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kenwood 440 mods

warning never do these!!

Type: Amateur HF transceiver
Frequency range: TX: 10-160 m + WARC
RX: 0.15-30 MHz
RF Power output: Max 100 W (AM: 50 W)
Sensitivity: N/A
Selectivity: N/A
Image rejection: N/A
Voltage: 12-16 VDC
Current drain: RX: 1.9 A
TX: Max 20 A
Impedance: 50 ohms, SO-239
Dimensions (W*H*D): 270*96*313 mm
Weight: 6.3 Kg
Manufactured: 1986-19xx
Other: Auto-AT option.


Kenwood TS-440S (TS 440 S TS440S) Circuit Improvements

Problem: Limited transmit frequency coverage.
Fix: Cut D80 on the Control Unit for 1.6MHz to 30MHz transmit capability. D80 is about 2" from D66, which is cut for 10Hz frequency readout.


Problem: Lack of crispness in the RX audio, which makes the sibilant parts of human speech hard to distinguish from each other. This is caused by a ­p;5db roll-off at 3000Hz in the RX audio.
Fix: Change C51 [0.033µF] on the IF Unit, near L5, to .005µF [5000pF/5nF]. This will reduce the roll-off to a more acceptable ­p;1.4db at 3000Hz. "After modification, the RF Gain control should be backed off [CCW] until the band/sky-noise decreases to a comfortable listening level. This will not interfere with the reception of moderately weak signals.

Problem: Even while listening on a large, external speaker, music sounds flat and tinny because the audio frequency response rolls off below 200Hz.
Fix: There are a number of capacitors in the RX audio amplifier circuits that can be increased in capacitance to restore the low-end audio. These capacitors are in the IF Unit. They are: C60, C66. C67, C69, C170 and C175. The increase in capacitance should be 4 times. {Note: Some capacitors in the audio circuitry can not be arbitrarily increased in value without causing unacceptable tradeoffs.} C175 can be replaced with a 1000µF, 10V unit, whose full-length leads are sheathed in Teflon sleeving, except for the last 8mm, to allow soldering to the PC board. This is done because the board-space allotment for the stock C175 is too small for the larger, replacement unit. The new capacitor is folded over and tucked in appropriately.

Problem: Tinny/thin-sounding transmit audio.
Fix On the IF Unit, change C135 {0.1µF}, near the center-board fastening screw, to 0.47µF.

Problem: The stock, muRata CFJ455K14 SSB filter in the 455KHz IF has a selectivity shape-factor of 2 to 1. This is definitely less than wonderful. The stock SSB filter in the TS-830S and TS-940S has about the same bandwidth at minus 50db, but it has a much better shape factor and it is mechanically and electrically interchangeable with the stock filter in the TS-440S. The better filter is a muRata CFJ455K12 or CFJ455V12, which will noticeably improve the transmit and receive, SSB audio quality of the TS-440S. This filter is available from Trio-Kenwood as p/n: L72-0333-05 for $42.89 {Dec 1989}. If you want SSB double-filtering in the 440's RX, the TS-940S' matching, 8.83MHz, YK-88-S1, 2.7kHz SSB filter is available from Trio-Kenwood as p/n L71-0222-05]. for $66.62 {Dec 1989}. This filter goes in the optional SSB filter space on the IF Unit. For listening to an uncastrated-male voice, the YK-88-S1 will produce better-sounding, and more understandable, audio than the Kenwood-recommended optional YK-88-S, 2.4kHz filter. A pair of TS-940 SSB filters will give the 440 the same superb selectivity that comes with the 940.


Alignment: Supply a signal to the receiver. Set the TS-440S' selectivity switch to M2, the single filter position. The USB and LSB carrier oscillators [DIP switches on Control Unit] should be reset so that there is roughly 20db of RX, SSB carrier-suppression for each sideband at zerobeat. [use the 440's 20db ATTN as a standard] {Use 15db rolloff at zero-beat for more low-end audio, or 25db roll-off for more high-end audio and/or better unwanted sideband suppression} This completes the alignment of the carrier oscillators. >>> If you installed BOTH filters: on LSB tune the 440 above the calibrator's zerobeat frequency and note the 20db (or the roll-off db you used above) roll-off point. This should be around 3.1KHz, ±200Hz higher than zerobeat. Put this frequency & LSB into VFO B. Put the zerobeat frequency & LSB into VFO A. With the Selectivity switch set to M1 [double SSB filter], the 8.375MHz oscillator on the IF Unit is adjusted [TC2, in the lower left corner of the PC board] so that the improved skirt selectivity on the double filter position is equally distributed between the zerobeat 20db rolloff point [VFO A] and the high-frequency 20db rolloff point [VFO B]. The comparison can be done by watching the S meter and repeatedly pushing the A/B button on the 440. [use fast AGC to reduce settling time] Note 1: TC2 is installed backwards on the PC board so that the rotor adjustment slot on TC2 is hot instead of grounded. This causes the capacitance of TC2 to change when a metal screwdriver is used to make the adjustment.

To fix this problem, TC2 is removed, reversed 180 degrees and re-soldered on the PC board. Note 2: see IF Unit schematic, CF2, the AM filter. There is a 1K Ohm resistor [R49] in series with the input [D13] to the filter. This resistor provides a closer impedance match between the 2000 Ohm filter and the source [L4]. A similar resistor can be installed in series with D12 at the input to CF1.

Problem: RX audio distortion. {This problem seems to be more prevalent in early production radios. There may have been a recent factory component change to reduce receive distortion.} There is one designed-in source of distortion and several other possible sources of distortion. The designed-in source of distortion exists because not enough forward bias current is applied to the switch diodes that select the SSB [D23] , AM [D24] , and FM [D25] audio detectors. Here's why: A mixer is a nonlinear device. Nonlinearity and distortion go hand in hand. Diodes make good mixers when their forward current is in the range of 0.05mA to about 0.6mA. At currents above 1.5mA, diodes are reasonably linear and they make good switches. The switch diodes in the TS-440S have enabling currents of from 0.2mA for FM to 0.28mA for SSB, so the switch diodes are operating in the region of maximum nonlinearity, which results in distortion. The fix is simple: Increase the forward bias DC-current through the diodes to roughly 2mA. This is accomplished by decreasing the resistance of each DC-bias resistor to about 1k Ohm. When these resistors are decreased in value, the 5000 Ohm impedance of the low-level audio circuits decreases to about 500 Ohms and the values of the coupling capacitors must be increased accordingly to prevent a rolloff of the low frequencies. Similarly, the resistors that are in series with the audio signals in these circuits must be decreased in value to offset signal attenuation. The capacitance of the filter capacitors between switch diode bias resistors (for SSB: C52, 4.7µF) must be increased to compensate for the decreased value of the bias resistors.
Fix for SSB audio detector and D23 switch: In the left, rear corner of the IF Unit, change: R71, R73, R74, and R85 to 1k Ohm; C53 to 47µF, 10V [XL=68 Ohms at 50Hz]; C52 to 22µF, 16V.
I'm guessing that similar changes can be made in the AM and FM detectors. This project can become tricky since some of the needed changes can also affect the transmit÷receive transition performance of the radio. Thus, it may be necessary to compromise by lowering the switch diode bias current to about 1mA. In general, this can be done by using 2k Ohm, instead of 1k Ohm, bias resistors.
If, after the changes are incorporated, you can still hear RX distortion on SSB, the problem may lie at the
[right-adjacent} product detector. Possible FIX: Install the missing injection-oscillator terminating-resistor at the product detector. This resistor is 62 Ohm, 1/8W or 1/4W. It is soldered under the IF Unit PC board, near L5. The terminating-resistor is soldered to the junction of R69 and R70 and the ground foil at the edge of the PC board. If the distortion persists, you may have an unmatched set of Germanium product-detector diodes: D19, D20, D21, and D22. These diodes can be replaced with Schottky diodes. The product detector balance should then be checked and adjusted as follows: Connect an RF detector to the emitter of Q9/R77. R77 sticks up from the board at one end so that the test connection can be easily made. The RF detector can be an oscilloscope, detector/probe for a DMM, or a 455KHz receiver coupled through a 10pF capacitor. With no signal input to the ANT jack, turn the RF Gain on the 440 to zero. Set mode to USB, IF Shift to detent. Adjust TC1 [also installed backwards, like TC2] for minimum RF. End of test. Reset the RF Gain control to normal.

Problem: AGC overshoot while receiving strong SSB signals. The symptom is audio distortion on peaks only. The distortion is reduced when the RF-gain control is backed off.
Fix: On the RF Unit, near J13, near Q5, change R42 from 470k Ohm to 10k Ohm. This speeds up the attack response of the AGC.

Problem: TX frequency response is not the same as RX frequency response with the IF Shift control set on detent.
Fix: Connect a frequency counter to IF Unit, J26, pin 2 and ground. With the IF Shift on detent, the frequency [roughly 455kHz] of the carrier oscillator should not change between TX and RX. If the frequency changes, adjust VR7 until the frequencies are equal. VR7 is just behind the MIC pot and the top of the front panel; it is mounted on a small, PC board.

Intermittents. The interconnecting wires in the TS-440S are copper. The tin-plated single-row connector pins that are crimped to these copper wires form a dissimilar metal junction that is subject to electrolytic action due to moisture in the air. Some of these crimp connections may eventually fail to provide electrical contact due to electrolysis.
Fix: Remove the defective connector pin by depressing the ratchet-tab in the slot on the side of the connector pin and pulling the freed pin from the connector body. [The ratchet-tab can be depressed with a small screwdriver.] The copper wire that protrudes past the crimp is then electrically bonded to the pin with solder or Silver Print [GC Electronics] conductive paint. The wire/crimp junction should be inspected with a magnifier before the pin is re-inserted into the connector. If a wire/crimp junction is soldered instead of being dabbed with conductive paint, it is difficult to prevent the heat from melting the plastic insulation on the wire. If soldering is the choice, the rosin flux residue should be removed from the pin with alcohol, or acetone.
The same type of intermittent problem may also occur in the coaxial connectors. The fix is to apply conductive paint between the crimp on the center conductor pin and the copper wire.
An intermittent frequency display or wandering SSB receive frequency can be caused by a dirty socket-to-chip contact on IC52 in the Control Unit.

On later production radios, IC52 may be soldered in. The same symptoms can also be caused by a bad solder connection on R152 in the 36MHz VCO [VCO #5] at the front-center of the PLL Unit, near T20. Another common problem with VCO5 is L41 [10µH] which apparently suffers from an intermittent internal connection. L41 is potted, so the best fix may be to replace it.
A very common problem with VCO5 is that the type of glue that is used to mechanically bond the components together appears to absorb moisture from the air (it is hygroscopic). Since water has a dielectric constant of 79, its presence can cause much grief in an RF circuit. Thus, the moisture that is absorbed into the glue can cause the oscillator to unlock.
Fix: Remove the original glue with solvent and a knife. If the glue is not replaced, VCO5 will exhibit microphonic problems. Some types of clear hot-glue seem to work well for replacing the original glue. Re-adjust VCO5 after the glue has set up.

Problem: No direct access to RX input or RX mute. These capabilities are necessary if the 440 is to be used as a slave-receiver in conjunction with another transceiver.
Fix: On the IF Unit, connect a wire from the base of Q39 to J22, pin 2. Remove R176, near J22. On the X41-1610-00, (M/14) Switch Unit at the rear of the 440, jumper across R46 [10K Ohm]. The RX will now mute when the FSK IN jack is grounded. {FSK TX is still possible if the AFSK is fed into the MIC jack through a 10 to 1 voltage divider.} The receiver input access can be brought out to the ACC 3 connector by connecting a 27 Ohm to 51 Ohm 1/4W resistor to J29, pin 2 on the X41-1610-00, (N/14 ) Switch Unit. A short length of wire connects the other end of the 1/4W resistor to the center of the ACC 3 jack which is now the RX input. When slaved to another transceiver through the transverter port, this arrangement allows the operator to simultaneously listen on 2 frequencies with stereo earphones. This provides an advantage to the user when working DX on split frequencies.

Problem: There is no way to adjust the reference frequency oscillator with the case on. If the frequency is adjusted with the case off, the frequency will be different with the case on.
Fix: drill a 7mm to 8mm hole in the left side of the bottom half of the case. The hole should line up with TC1 on the PLL Unit. The position of the hole can be located with the case in place. The horizontal measurement is 122mm back from the edge of the front panel that wraps around the left side of the radio. The vertical measurement is 6mm below the edge of the top half of the case that overlaps the bottom half of the case.
To adjust TC1: [You must have 10Hz readout enabled] Tune to 10.00000 MHz WWV, USB or LSB. Select W [wide] on the selectivity switch. Wait until the tone modulation is present. You will hear both sidebands. If the 2 tones are not the same, adjust TC1 until the tones zerobeat.

Problem: On QSK and on SSB VOX, it does no good to back off the RF Gain control to reduce the nuisance of static crashes or band noise. This is because the factory stock receiver comes on full-bore whenever the TS-440S transitions from TX to RX - even if the RF Gain is backed off!
Fix: On the IF Unit, change R36, near Q5, to 2M Ohm; change R60, near Q7, to 510K Ohm. ± a few standard values will make little difference.

Problem: Your own transmit RF gets into the TS-440S through the EXT SP jack and causes audio rectification that is heard in the external speaker.
Fix: The sleeve/shield terminal on the EXT SP jack should be bypassed to ground on the (G/14) Switch Unit with a 2nF to 20nF, 500V, disc ceramic capacitor.

If the problem is most severe on 10 meters, try 2nF [.002µF]. If the trouble is most severe on 80m or 40m, try 20nF [.02µF].

Problem: You can hear distorted audio coming out of the internal speaker while you are transmitting on SSB.
Fix: Remove the top cover on the radio and re-position the internal speaker wires away from the area around the SSB filters. The speaker wires should be confined to the area around the speaker plug on the IF Unit. Also, keep the speaker wires away from the Control Unit behind the digital display.

Problem: Key-clicks on CW. This is caused by too fast (500µS) RF output rise [make] and fall [break] times.
Fix: On the IF Unit, change C168, near Q49, to .22µF; change R225 to 33K Ohm-43K Ohm. {the factory's "fix" for this problem is OK on make but it still clicks on break}. Unfortunately, fixing the key-click problem also seems to affect the full breakin make timing in the 440 which clips the first dit. Thus, if you want to use the 440 on full, instead of semi, breakin, you must put up with the key-clicks.

Problem: The amplifier-keying-relay, RY2 on the (N/14) Switch Unit, makes too much noise, or the contacts on RY2 have burned and pitted, or all of the above. Another problem with RY2 is that it is too slow to use with a full-QSK amplifier. This needless make-delay can cause the amplifier to hot-switch, burning the contacts in its QSK-relays.
Fix: replace RY2 with an NPN switching transistor and fix the current pulse problem that pitted the relay contacts, which may also damage the transistor. [only works for amplifiers with positive voltage relay control]. If your amplifier uses positive 110V for the relay control, like the SB-220 and the TL-922, the relay pitting is caused by the current pulse from the repeated shorting out of the charged .02µF bypass capacitor across the amplifier's relay control jack. The bypass-capacitor can be removed if shielded wire is used for the interconnection cable to the transceiver. Another fix is to install a 150 Ohm to 200 Ohm, 1/4W series resistor at the relay control jack to limit the discharge current to a value that the relay or switching transistor can handle. The bypass capacitor is connected to the relay-side of the resistor.

Transistor Installation Notes: The N/14 Switch Unit is located just behind the ANT RF connector on the rear panel. The small access panel on the bottom, rear of the radio is removed to gain access to the N/14 Switch Unit. Two chassis-ground connections and one center pin connection must be unsoldered from the RF connector before the Switch Unit can be removed. Unplug the three connectors, remove the two sheet metal screws, and lift out the Switch Unit. Unsolder and remove RY2, D16, and the white jumper-wire and the pin that it plugs into. Install one 1k Ohm resistor each in place of D16 and in place of the jumper-wire and its pin. The transistor will solder in place of the relay if its full length leads are bent to fit the available holes. The emitter goes to common-ground, as does the trace to J30, pin4 [CMC], the ground return for the relay control circuit. The base lead connects to the trace that goes to R2 {D16} and C37. The collector solders to the trace that connects to J30, pin 2 [TXC].

Problem: Poor skirt selectivity on AM.
Fix: The unsatisfactory, stock, TS-440S AM filter, CF2, can be directly replaced with the better performing, AM-narrow, 6KHz filter from the Trio-Kenwood R-1000 receiver. The part number of this filter is L72-0319-05 and the price is $9.10 {Dec 1989}. It is available as a replacement part. Even though the better filter has more pin connections and is physically larger than the original filter, the IF Unit printed circuit board was designed to accept either AM filter. The design engineers must have realized that some people would want to install a good AM filter.

CF2 is a small, black, cube-shaped plastic component at the rear of the IF Unit just slightly to the right of left-to-right circuit board center. No realignment is necessary after the AM filter is replaced.

Maintenance: The VFO tuning knob should be removed, after loosening the 1.5mm hex-socket set-screw, and the tuning shaft's bushing-bearing should be lubricated with a modern semi-synthetic lubricant like Break Free or Tri Flow. The quantity of lubricant used should be small and the radio should be tipped back to help the lubricant run down into the bushing-bearing. This should be done once when the radio is new and roughly every 4-years thereafter.


Double-sideband modification for the TS-440S

Occasionally, it may become advantageous to use double-sideband-transmit and single-sideband receive mode in order to thwart the efforts of radio sociopaths who are gratified by interfering with others. DSB-xmit/SSB-RX mode gives the non-interfering stations the option of listening to the sideband that has the least amount of interference.

To install DSB capability in the TS-440S, the audio processor switch is rewired so that when the switch is depressed, the carrier is removed from the AM transmit signal. Without a carrier, AM becomes DSB. {The DSB modification will disable the less-than-worthless audio-PROCessor in the TS-440S.}

The modification: On the IF Unit [the top board] locate R179, which is between IC4 and Connector 21 at the front, left of the circuit board. Remove R179 and connect a jumper wire from the right hand, empty solder-pad hole on the circuit board [collector of Q41] to the junction of D45 and R196, which is straight back on the circuit board, just to the left of IC5; about 4cm from the rear of the circuit board.

To enable DSB transmit/SSB receive, "SPLIT" operation is utilized:

  1. Program VFO A=B.

  2. Program VFO A for either USB or LSB, depending on which one has the least interference.

  3. Program VFO B for AM and push the PROC [DSB] switch in to remove the AM carrier.

  4. Select VFO A.

  5. Program SPLIT operation. The 440 will now listen on VFO A and transmiton VFO B.

  6. Set the carrier control straight up to position #5 [12 o'clock].

  7. While transmitting, adjust the MIC gain control for a small amount of ALC. This keeps the DSB bandwidth to a minimum.

While listening [VFO A], it may be necessary to select the sideband that has the least amount of interference. If your friends are also transmitting on DSB, you may be able to continue communicating, despite the efforts of those who would like to spoil the enjoyment of others.

>>>DSB should not be used unless the other sideband is vacant. If the interfering station or stations can cause the group that they are interfering with to interfere with a third group, it will definitely make their day.

Most jammers enjoy being talked about, either positively of negatively. This is why they usually switch back and forth between receive and transmit. If you want a jammer to stick around, talk about him. Stupid insults usually work best.

Kenwood TS-440S (TS 440 S TS440S) mod for improved receive sensitivity of 0.5 to 1.6MHz

TS440S mod for increasing sensitivity on the MW AM broadcast band:

(Removes MW attenuator pad). The TS440S has an attenuation pad hard wired on the spectrum between 500KHz and 1600KHz. You can open up sensitivity by removing it. On the RF unit board, clip a lead on R13 68 ohms), clip a lead on R14 (68 ohms), and solder a jumper across R12 (220 ohms). These are under a shield held down by screws on the RF board.

I've noticed no intermod problems and only the strongest stations (above S + 40) overload (which can be solved by using the front panel attenuator button).

Proceed at your own risk.

The VCO and active low pass filter are sealed in synthetic rubber to mechanically stabilize them during mobile operation. Over a period of several years, the rubber's insulation properties can break down. This may be caused be repeated temperature variations. This can cause the VCO to vary in frequency which will force the loop to unlock or cause the audio to warble.

This modification will correct or prevent an unlock caused be VCO #5.

Required parts:

2SC2459(BL)      Transistor          QTY. 2
1SV153           Varactor diode      QTY. 1
  1. Disconnect the power supply and antenna.

  2. Remove the top and bottom covers. Do not damage the speaker wires when removing the top cover.

  3. Remove the two screws from the rear of the IF unit and raise the unit to expose the PLL board.

  4. Remove the 8 screws from the PLL board and disconnect all the cables going to the board.

  5. Remove the board from the transceiver.

  6. Remove the shield cover from VCO #5. Desolder and remove the shield from the PLL board.

  7. Carefully remove the synthetic rubber from the area of Q34, Q35, and D14. The rubber must be picked off the board with pointed tweezers or some other tool. It cannot be removed with any type of solvent as this will harm the components in the area.

  8. Desolder and remove Q34, Q35, and D14 from the PLL board.

  9. Check the component side of the board to make sure all the rubber in the area of Q34, Q35, and D14 is removed.

  10. Once the rubber is removed, replace Q34, Q35 and D14 with new components.

  11. Inspect and resolder the foil side of the PLL board under VCO #5.

  12. Install the VCO shield on the PLL board and solder it in place.

  13. Seal the VCO with hot melt glue (glue stick used in a hot melt glue gun). Apply the glue to the circuit from the glue gun. Once the area i covered, use the hot air gun to flow the glue around the components. Do not overheat the components.

  14. Install the PLL board in the transceiver.

  15. Apply power to the transceiver and allow it to run in receive for about a half hour so the transceiver's temperature stabilizes.

  16. Set the operating frequency to 14.200 MHz.

  17. Adjust T20 to obtain 5 Vdc at TP11 (the exposed lead of L40) measured with a DVM or VTVM. Do not use a VOM. After adjusting the VCO, bench run the transceiver for an hour or more to make sure the circuit is stable.

  18. Assemble the transceiver.


Time required to perform this modification is 1 hour or less.

Kenwood TS-440S (TS 440 S TS440S) PLL unlock due to VCO #1

The TS-440S Control unit supplies band information to four circuits in the transceiver. The circuits are the receiver front end Band Pass Filter (BPF), the antenna tuner (AT), the transmitter Low Pass Filter (LPF), and the VCO circuits on the RF board that are part of PLL #1.

There are ten receiver front end BPFs that are diode switched into operation. If one of the diodes (D4-D23) becomes shorted or leaky, the band information is felt at two BPFs at one time. The voltage going through the bad diode will loop back to the VCO circuit, antenna tuner circuit, and LPF circuit.

The unwanted voltage will then create one or more of the following symptoms:

  1. PLL unlock (the transceiver only displays decimals).

  2. No antenna tuner operation.

  3. Low receiver sensitivity.

  4. Low or no transmit power output.

  5. Distorted transmit audio.

  6. RF feedback.

The most common symptom is the PLL unlock. To test the diodes, remove the large shield on the RF board to expose the BPF circuits. Reset the transceiver by holding in the A=B button as power is turned on. Even if the display only shows decimals, only the BPF for 14 MHz should be turned on. Using a DC voltmeter, measure the voltage at coils L11, L15, L21, L28, L34, L40, L46, L52, L58, and L62. Only coil L52 should measure 8 Vdc. The other coils should read 0 Vdc. If one reads 0.5 - 8 Vdc, replace the two diodes in that BPF circuit.

Coil/Diode/frequency range relationship:

L11  D4   D5           0 - 0.5 MHz        L15  D6   D7         0.5 - 1.6 MHz
L21  D8   D9         1.6 - 2.5 MHz        L28  D10  D11        2.5 - 4 MHz
L34  D12  D13          4 - 6 MHz          L40  D14  D15          6 - 7.5 MHz
L46  D16  D17        7.5 - 10.5 MHz       L52  D18  D19       10.5 - 14.5 MHz
L58  D20  D21       14.5 - 22 MHz         L62  D22  D23         22 - 30 MHz
Replacement diode part number
1S2588 or 1SS91S:    D4, 6, 8, 10, 12, 14, 16, 18, 20, 22
BA282                D5, 7, 9, 11, 13, 15, 17, 19, 21, 23


Time required to perform this modification is 1 hour or less.

Kenwood TS-440S (TS 440 S TS440S) Intermittent operation

When intermittent problems such as erratic display, loss of front panel control, or frequency lock-up are encountered, the PLL and Control circuits must be checked to determine which circuit is malfunctioning. While any number of components may cause such problems, if the Control circuit is suspect, there is a possibility that the ROM socket is at fault. The socket should be tested to determine if it is making good electrical contact with each pin on the ROM. If it is found to be defective, remove the socket and solder the ROM directly to the board. The ROM is IC52 on Control unit (B/2). It should be noted that units with serial number of 909xxxx and above do not incorporate a socket.


Removing the socket requires good soldering skills. The ROM is mounted on the Digital A unit and is designated as IC2. The board, being double sided, has solder connections on both component and foil sides. When the socket is removed, it is very important to insure that each pin is completely solder free. Having to pry up on the socket means that it is not completely desoldered and will cause the circuit foils to tear.

When performing any work on the Control boards, CMOS handling techniques must be observed. Such techniques include using a grounded or isolated soldering tip, avoid touching the pins of IC chips with your fingers, and ground yourself with a wrist ground strap.

To remove the socket:

  1. Disconnect the power supply and antenna.

  2. Remove both the top and bottom covers from the transceiver. Disconnect the speaker cable from the transceiver.

  3. Remove 2 countersunk screws from each side of the front panel chassis and gently pull the front panel forward.

  4. Loosen the 5 round head screws (2 on top and 3 on the bottom) that secure the shield plate inside the front panel and then remove the plate.

  5. Set the transceiver on its left side and fold the front panel back to expose Control board (B/2). Do not stress the cables.

  6. While avoiding contact with the pins, remove the ROM (IC52) and set it aside on anti-static foam.

  7. Unplug connectors 56 - 58 from Control board (B/2).

  8. Remove 3 brass screws from Control board (B/2). Do not remove the fourth screw that connects to the angle bracket. Instead, remove the brass screw from the Control board (A/2) so the angle bracket stays with the top board.

  9. Fold the top board towards the body of the transceiver. Be very careful not to stress the flat ribbon cables that are soldered between the two boards.



If the foil side of the board id not sufficiently exposed for desoldering purposes, remove the 3 hex bosses from the bottom Control board. Pull both boards forward and open them like a book to allow the best access to the foil side of Control board (B/2).
  1. Carefully desolder the socket and remove it from the board. Do not pry up on the socket. If it does not easily pull off the board, the top foils are still soldered to the socket.

  2. Install the ROM in the board and solder it in place.

  3. Assemble the transceiver by reversing steps 1 - 9. If the bottom board was removed, do not pinch the wire harness under the board during installation. If the harness produces excessive stress on the board, solder connections may become intermittent.

This modification may be covered under warranty during the warranty period.
Time required for this modification is 1.5 hour or less.

Kenwood TS-440S (TS 440 S TS440S) SSB Power-adjustment

Hello TS 440 user.

The last few weeks I've seen questions of how to make the power in SSB mode for the TS440S adjustable without changing the Mic-Gain. It's a very easy job to do.

Take off the top cover of the rig.
At that moment you have a sight on the first unit (IF-Unit)
Than you have to look for Diode 49.
You will find Diode 49 at about 5 CM from the backend of the unit and about 6,5 CM from the leftside of the unit.
Just next of C138 and between plug 38? (red/orange wires) and plug 26 (black-cover/blank wires) Just cut that Diode 49,bend one part a little away and leave the part's where they are. It's the best way to do I think.
Replace the topcover.
From now on it is possible to adjust only the power in SSB mode by just turning the CARRIER Control at the front of your rig and leave the Mic-gain for where it is.
Turning counterclock will minimize the power until a 20mW or something like that.
Because most TS440 users have'nt used their carrier control that much I think it's better to pull off the MIC/CAR knobs and spray some contact cleaner in the shafts. (I know,it's not the best way).
When you switch your rig into the CW mode you can adjust the power in what you like,switch the mode in to USB or LSB and if it is correct the power will not come above the level that what you have adjusted in the CW mode.
Just simple , is'nt it?
Of course you will do this all in your own responsibility because I won't take any!!! Agree?
Kenwood TS-440S (TS 440 S TS440S) Digital Audio Modification

Please be very careful with your transcievers, and we accept no responsiablity for any damage that may be incurred, and this modification may, and proably would be cause for any WARENTY to be DISCONTINUED.

This Modification allows for the Kenwood TS-440s transceiver to have the data audio on PIN 11 of the 13 pin DIN connector ACC JACK 2. Later models may or maynot have a correction for this, but my PK-232, or for that fact NONE of my TNC's would drive the audio to the PIN 11 of ACC JACK 2. Encountering this problem, and having another H.F. transceiver I have been using the REMOTE connector, and using an audio input to the AFSK IN RCA type connector. This would allow me to use the same cable with my TS-180s also. Anyway this modification moves the wire's from the AFSK IN to the ACC 2 connector. This should only take about 20 to 30 minutes to preform this change, and most of the time is used up with the removal, and replacement of the THREE covers of the transceivers cabinet.

The circuit boards to work with, are called:
DISPLAY UNIT (X54-1870-00) (C/4) This has the ACC 2 JACK.
SWITCH UNIT (X41-1610-00) (M/14) This has the AFSK INPUT.

The eaiest way is to remove these two boards 4 screws hold the ACC 2 JACK, and 2 screws hold the AFSK INPUT board in and they are located at the rear of the transceiver. If you are interested in following the SCEHMATIC in your manual, the leads you will be working with are ANI, and GROUND which is the PURPLE LEADS, and the FSI lead and GROUND, which are the GREEN leads.

The problem is that when kenwood designed this rig, they brought the DATA INPUT(ANI) from the ACC2 JACK to connector J25 of the IF UNIT.
This coming in after the Processor, and Microphone Amplifier does not allow sufficent amplification of the signal, thus very low, or no audio at all. What this modification does is swap at the rear of the RIG the FSI, and ANI signals, Which also could be done on the IF UNIT board, and for some may actually be eaiser. In my case the leads were just a bit too short to allow this modification to be accomplished on the IF UNIT.


  1. Be shure to have on a work bench, and NO POWER APPLIED!
  2. Remove the TWO BOTTOM covers, One MAIN cover, and the smaller cover to the REAR of the transceiver.
  3. Remove the TOP cover.
  4. Remove the FOUR screws holding the AUTOMATIC ANTENNA TUNER.
  5. Place the transceiver on it's side with the BOTTOM towards you, and the FRONT to your LEFT.
  6. Being very careful, remove the antenna tuner and allow it to hang.
  7. Remove the TWO SCREWS that HOLD the AFSK INPUT board.
  8. Remove the FOUR SCREWS that HOLD the ACC 2 JACK board.
  9. Carefully from the inside of the transceiver, pull these TWO boards out.
  10. Near the Bottom edge of the ACC 2 JACK board, is a TWO lead connettor, unplug this. The leads should be PURPLE.
  11. On the AFSK INPUT board, there is a 6 PIN connector, unplug this. The leads you will be working with are GREEN in color.
  12. Note how the PURPLE leads are connected to the connector itself, and remove these two leads by inserting a very small screwdriver into the slot on side, and being very gental, push the leads out one at a time.
  13. Now remove the GREEN leads the same manor.
  14. Insert the GREEN leads into the 2 PIN connector, the BLAC lead is the GROUND, and the WHITE or perhaps YELLOW is the AUDIO lead.
  15. Insert the PURPLE leads into the 6 PIN connector, noting that the smaller lead is the AUDIO lead, and it connects to PIN 2, the other lead, being BLACK goes into PIN 1.
  16. Now reassemble in reverse order the BOARDS, and start at STEP 11, and work in reverse to STEP 1.


Kenwood TS-440S (TS 440 S TS440S) Fan Temperature Modification

I don't know about you, but I don't think solid state equipment needs to run hot enough to fry an egg on. The fan on the 440 is set to come on at 50 deg C. That makes the heatsink hot enough that you can only put your hand on it for about 3 seconds without being in pain.

Looking at the schematic and pondering the situation, I decided that it would be quite easy to change the "trigger" point for fan operation. This mod will do just that and not effect the "high-temp-shutdown" mode that is provided in case the fan dies. Actually, it wouldn't be a bad idea to make the same sort of mod to that circuit too, but let's just do this one for now. I'll put out another bulletin on this if I go into the failsafe circuit.

The fan is controlled by two sensing circuits on the FINAL UNIT. On the schematic, Q9(1/2) is the failsafe trigger that activates the powerdown circuit in case the final reaches 80 deg C. It won't normally do this, even under continuous keydown conditions, unless the fan has failed.
Q9(2/2) is the stage that controls operation of the fan. It is a simple voltage comparator and therefore can be made to trigger wherever you want.
TH1 is a thermistor with a negative coefficient. That is, when the temp rises, the resistance goes down. This pulls the - input to Q9(2/2) lower and lower until it is at or below the 2.26v reference that is present on the + input of the same stage. At that point, the output flips high and turns on Q8, thus turning on the fan. By raising the reference voltage at the + input, the TH1 voltage will fall to the reference voltage sooner and turn on the fan at a cooler temperature. By clipping the top loop of R27 on the final unit (2.2k res. that provides reference voltage) and temporarily inserting a 5k precision multi-turn pot in series with it, I determined that I liked the way it operated with about 800 ohms extra resistance in the circuit.

I then installed an 820 ohm fixed resistor in series with the cut loop. I also put a very small dab of silicon seal between the new "hung" resistor and the ferrite transformer right next to it so that there would be no added strain on the remains of R27. The alternative would be to remove the final unit completely and do the mod the right way, replacing the complete R27 with a 3k resistor. This was a step that I didn't really want to perform on a two week old rig. When you choose your series resistance, remember that the more resistance you add to it, the sooner the fan will turn on. If you go too high, it will be on all the time.

This modification brings the fan on at least 10 deg. earlier. By the way, my only reservation about this mod is the added wear and tear on the fan unit itself. I have been buying parts from Kenwood for about 10 years now and they have always seemed remarkably inexpensive. Ordering a spare fan to have on hand seems like a very reasonable thing to do if you are worried about it.
Kenwood TS-440S (TS 440 S TS440S) Possible cure for TS440 showing dots only on display

The most common reason for the the display to show only dots, is that one of the phase locked loops is not locked. So take of the top cover. You will be looking at the IF unit. This board is mounted in a hinged frame. It hinges on two screws near the front pannel sides. So remove the other two screws near the final unit instead and hinge the IF board towards you. You now uncovered the PLL unit.

There are five PLL's on this board. Each one has a pin indicating if its loop is locked or not. So get out a volt meter and set it for 5 volts full scale. Now check pin 2 for each of the following IC's. IC18, IC1, IC4, IC9.
Also check pin 7 of IC17. If all the loops are locked, you would see a steady voltage there in the neighbourhood of 4.7 volts. If any of the loops is not locked, one of these pins has a voltage well below 1 volt.
Note the IC number so you can look up which VCO you may have to tune a bit so it will lock again.
IC18  VCO#5 T20
IC1   VCO#4 T1
IC4   VCO#3 T2
IC9   VCO#2 T9
The above are all located on the PLL board.
The VCO for IC17 is actualy one out of four different VCO's selected on the RF board. Which one of these depends on what band is selected.
If you have display dots on all the bands, then you have no problem with the PLL made up with IC17. So you only have to adjust either T1, T2, T9 or T20.

Now here it goes. Make sure you have an alignment tool that isn't to small or to large for the slots in the slugs in the coils (T1, T2, etc.) Also, absolutely don't turn any other coil than the one that belongs to the unlocked PLL. If you do so anyway without a service manual and proper equip- ment, then you are likely stupid.

Only turn the indicated slug. First turn it 1/4 clock wise and see if it is ok now. If not, turn it 1/4 counter clockwise and see if it works. I suggest that you don't try more than one half turn either way. If you think that it needs to go that far, it likely has an other problem.

If the display dot problem only shows up on some but not all band, send me a note and I will see if I can help you.

The correct way would be to use a good voltmeter and follow the service manual for this adjustment. But in most cases, the above will do fine. I don't work for Kwood, I don't have a 440. Just a service manual for one. But I did cure some of the above problems.
Kenwood TS-440S (TS 440 S TS440S) Undocumented feature

The TS440 is nice. Here's what I've found out about it that isn't in the operation manual (in some random order):

Diode options: There are a bunch of configuration options controlled by clipping or inserting diodes on the back of the control board. You get to it by taking the top and bottom covers off (a bunch of silver screws), loosening the front panel (4 flat-head silver screws, NOT the black ones). Then you have:

   diode        controls                in              out (cut)
   -----        --------                ----------      ----------
   D65          mode confirmation       Morse           single beep
   D66          display resolution      100 Hz          10 Hz
   D67          memory protect          none            on
   D73          CW shift                800 Hz          400 Hz
   D78          WARC 24MHx band tx      disabled        enabled
   D79          WARC 18MHz band tx      disabled        enabled
   D80          General Coverage tx     disabled        enabled

Self-Test: You can run a rather complete test of the control logic by the built-in "semi-self-test", a series of 56 routines. To run this, turn the unit on whilst holding the AM and T-F SET switches pushed in. It changes to the next test when you turn the VFO knob clockwise. Turn the power OFF to reset the unit.
   Test         What it does
   ----         ---------------------------------------------------
     0          all positions in display light
     1          all segments in display dark
     2          all positions in display light
     3          all segments in display dark
     4          one digit lighted (rightmost)
     5          next digit lighted
     6          next digit lighted
     7          next digit lighted
     8          next digit lighted
     9          next digit lighted
    10          next digit lighted
    11          next digit lighted
    12          next digit lighted
    13          next digit lighted
    14          next digit lighted
    15          next digit lighted
    16          next digit lighted (leftmost)
    17          beeper sounds
    18          beeper silent
    19          all mode LEDs ON
    20          all mode LEDs OFF
    21          receive 
    22          transmit
The following tests change internal signals. They are most useful if you are trying to trace the circuits controlled by these signals.
You'll need a s service manual (or at least a schematic) to made reals sense of these.
    23          Band select - all lines high
    24          BAND select - all lines low
    25          PD select - all lines high
    26          PD select - all lines low
    27          ENF select - all lines high
    28          ENF select - all lines low
    29          ENP select - a:ll lines high
    30          ENP select - all lines low
    31          RES select - all lines high
    32          RES select - all lines low
    33          CO select - all lines high
    34          CO select - all lines low
    35          AX select - all lines high
    36          AX select - all lines low

these next tests check the outputs of the 8255 parallel port interfaces, which select several internal functions.
    37          (IC2) port A all lines high
    38          (IC2) port A all lines low
    39          (IC2) port B all lines high
    40          (IC2) port B all lines low
    41          (IC2) port C0-C3 high, C4-C7 low
    42          (IC2) port C0-C3 low, C4-C7 high
    43          (IC53) port C all lines high
    44          (IC53) port C all lines low
Following display busy lines and scan lines in the rightmost 9 digits of the display. You will push buttons to cause the digit to change from a 1 to a 0 indicating that the associated button has been pushed.
 test   bit8    bit7    bit6    bit5    bit4    bit3    bit2    bit1    bit0
 ----   ----    ----    ----    ----    ----    ----    ----    ----    ----
  45    LOCK            AT      Mic UP  Mic DN  PTT/AT                  VS1
  46 (none)
  47 (key scanner)
  48     1       6      V/M                     VOICE
  49     2       7      M>V     RIT             A/B
  50     3       8      SCAN    XIT             SPLIT
  51     4       9      M.IN    T-Fset          A=B     dip3    dip4    dip5
  52     5       0      CLEAR   1Mhz            dip1    dip2    dip6    dip7
  53                    ENT     DOWN            UP      dip8    dip9    dip10
(the digits 0-9 are on the front panel keyboard; dip2-dip10 are the segments of S50, the SSB frequency response dipswitch on the rear of the control unit printed circuit board.)

54 not used
55 not used
56 END
Kenwood TS-440S (TS 440 S TS440S) Serial interface

The TS440 has a serial ASCII interface option. You have to insert two chips into sockets on the back of the control unit circuit board to take advantage of this. IC54 is an 8251A Uart, and IC55 is a CD4040 divider. These chips are available from Kenwood together with a interface manual, or you can buy them at your local chip shop for about $6.00 or so. When inserted, the transceiver speaks 4800 baud ascii in/out the 6-pin DIN connector ACC-1 on the rear. The signals are from the 8251, but are inverted in a 74LS04 and RFI filtered before being brought out to the world. An interface box with inverter, RFI filter, power supply, opto-isolator, RS232 level shifters, and power supply is available from Kenwood for about $49.00, or you can build your own.

(Depending on how much your computer radiates and how sensitive to RF it is, you may only need 5v, +/-12v, a 74LS14, MC1488, and MC1489. If your computer has a TTL level serial port, perhaps all you'll need is the 74LS14. If you're not confident of being able to solve the possible digital/RF interface problems yourself, the $49 interface is proably a good buy.)
                ACC-1 Serial Interface
        pin     signal
        ---     ----------------------------------------------------
         1      signal ground
         2      data from transceiver
         3      data to tranceiver
         4      cts to transceiver - computer can throttle output
         5      cts to computer - transceiver can throttle input
         6      no connection
SSB frequency response dipswitch: located on the back of the control unit, this adjusts the frequency response of the upper and lower sideband modulators to compensate for component variations. Changing it isn't a good idea, since you have to have a two-tone oscillator and have to reset the carrier suppression adjustment if you do. The service manual explains this process; I'm including this here so that people who have been wondering what the dipswitch does won't screw themselves by flipping switches to see what happens.
Kenwood TS-440S (TS 440 S TS440S) A few adjustments you should know

A few adjustments you should know about (read the service manual before you tweak wildly on these!):

        tweaker         what it does
        -------         -----------------------------------------------
        RF-VR3          FM Microphone Gain
        RF-VR6          FM Deviation - set to 4.6KHz on dev meter
        IF-VR2          S-meter zero - set to zero with 50 ohm dummy load
        IF-VR3          S-meter S9 - set to S9 with 40dbu input 14.175MHz USB
        IF-VR4          Squelch threshold - close at 12 o'clock with
                        mode = CW and filter WIDE
        IF-VR9          CW side tone level - as you like it
        IF-VR10         Beep tone level - as you like it
Someone wanted to know what the difference between the DATA connections on ACC-2 and the AFSK connectors was. On output, none; the AFSK and the DATA out pin on ACC-2 are connected together, and are fed from the high side of the volume control - they are receiver audio BEFORE the cw sidetone, beeper, and voice response unit are mixed in, and should be a constant level independent of the AF gain setting. The AFSK input is different from the DATA IN connection; AFSK and microphone signals both go through the mike preamp and speech processor; the DATA input bypasses both. The MIC GAIN pot does control all three input levels.
(as a note, you can tap preamped/processed audio OUT of the DATA IN connection, since it is just a tap on the output of the preamp/processor. This is also the feed into the FM modulator. But NOTE that the MIC GAIN pot doesn't adjust the mic gain on FM - there is a separate tweaker for that.)
Kenwood TS-440S (TS 440 S TS440S) modification to use antenna tuner

Remove case from rig. Remove (4) screws that holds antenna tuner in place. Next slide antenna tuner out to get to the coax connections. Remove the in coax attached to antenna tunerfrom FO connector on filter unit (X51-1340-00). Remove coax from out connector on antenna tuner and install in FO CONNECTOR ON FILTER UNIT. Unplug and remove switch unit (X41-1610-00 N-14) from rig.
Remove short wire from antenna connector to PC BOARD. Cut coax on the in connector of antenna tuner in half and connect cut end to switch unit PC BOARD Where short antenna wire was removed and shield to ground. Solder other half of coax to antenna connector and shield to ground, and plug other end into out conector of antenna tuner. Your still have control of antenna tuner with auto and thru switch. It works very well. Maybe someone can use this idea.
Kenwood TS-440S (TS 440 S TS440S) display calibration

I found there was some shift in the reference oscillator frequency of my TS-440S. This can be noticed and corrected as follows:
  1. Remove the top and bottom covers from thd radio.
  2. Do not disconnect the speaker cable.
  3. Connect the supplied calibration cable between RF Unit and PLL unit, as shown in "Kenwood TS-440S Instruction Manual" on Page 24 in Section 5-8-3.
  4. Set VFO A to 10.001.00 MHz LSB and VFO B to 9.999.00 MHz USB.
  5. Pushing the A/B function button, you can have different audio signals, if that 36 MHz reference oscillator is miwadjusted.
  6. Using a small flat bladed scredriver, adjust trimmer capacitor TC1, near connector 8 of the PLL Unit (the location shown in Instruction Manual in the same section as above) until those audio frequencies from VFO's A and B are equal.
  7. Disconnect the calibration cable and reassemble the radio. This procedure can be done by ear with good accuracy without any measuring equipment. WWV is too weak here in Finland to use it as comparative signal for the procedured described in "Instruction Manual", Section 5-8-3.
Kenwood TS-440S (TS 440 S TS440S) Connection to a DATA

Connection of the KENWOOD TS440S to a DATA terminal such as a Kantronics KAM using the rear ACC2 13 pin jack.

                   ____ 4    3    2    1
       GROUND ___ |
                  |____ 8    7    6    5
                  |___ 12   11   10    9____________
                           /                        |
       MIC    ____________/    13                   |
                                |                   |
                                |                   |
                               \_/                 \_/
                              =====               =====
                                |                   |


       Pins        |           Application

        3              Data output - not used as the level is very low
                       the prefered connection is via the speaker output
                       this also allows fine adjustment of level to
                       enable best decoding. (A switch on the speaker to
                       'mute' it when required is a good idea.)

        4              Ground - you may have to experiment with these
        8              connections to eliminate RF feedback and noise.
       12              Here they are all strapped.

        9              Mic mute - prevents audio pickup from the mic when
                       earthed. By connecting to the PTT line as shown
                       through a diode automatically MUTES the mic when
                       using data. When the front panel PTT or MIC PTT
                       are used the microphone is 'live'.

      13               Standby - PTT which when taken to ground puts the set
                       'on air'. By connecting through a diode as shown
                       doesn't affect the PTT operation but allows auto
                       mic muting.
The diodes used can be virtually anything, here they are IN4148.

The INPUT audio to pin 11 must be quite a high level. If using a KAM you are certainly going to have to change the HF LEVEL JUMPER in the KAM. The level of the KAM as shipped suites connection to the FRONT PANEL MIC but not the rear connector, you can however correct this with the jumper. People using the PK232 have complained of NO TX AUDIO, I suspect the level is so low that only local minitoring will show a level present.
Kenwood TS-440S (TS 440 S TS440S) Computer Interface Instruction

These Instructions are TS-440 specific, but the basics also apply to the TS-940, TS-811 and TS-711.

It is possible to save yourself a few dollars and lose nothing in quality by buying the parts to upgrade your Kenwood radio for computer control. Just purchase the parts were you find them and install them using the instructions in the Radio's Manual.

     IC 54 is a uPD-8251-AC   Serial Communications Interface.
                Commonly called an 8251A    ($1.89 Mail Order)
     IC 55 is a TC-4040-BP    12 Stage CMOS Divider.
                Commonly called a 4040      ($0.69 Mail Order)
The IC-10 Interface Kit from Kenwood Contains ONLY these two parts and less instructions than are in this file. The only thing you are going to miss, is the $22+ price tag on the IC-10 Kit.

 Signals are    TTL levels  (NOT RS-232)
Baud rate is    4800 (1200 Opt.)
   Format is    ASCII Serial;  1 Start, 8 Data, 2 Stops
The Baud rate may be changed to 1200 Baud by removing jumper W50 and installing a jumper from the left pad to the center pad as viewed from the front of the radio. This will become obvious once you have the radio opened up. Many other Baud rates are possible, just look at the schematic.

As long as you are in the radio, lift D-66 to enable the 10 Hz. display. The main tuning knob is varing this digit, so you might as well see it. It also helps when using RIT/XIT as the RIT/XIT display does not resolve the 0.01 KHz. digit. This Modification is in the Radio's Book.

Not in the book is the fact that if you lift D-80 and do an MPU reset, you will be able to transmit on any frequency between 1.5 and 30.0 MHz. This means you will be able to work the Mars nets, Etc. Do not transmit out of band. It is illegal even if it is accidental.

Some computers use TTL levels on their serial ports. If so, here is a time when you will not have to convert it to RS-232.
The IF-232 Interface from Kenwood is a 1488 and a 1489 chip in a box. These are an RS-232 Quad Line Driver and Receiver and are available at Radio Shack for $1.29 Each. Here is an easy project that will save you a lot over the $69+ Kenwood price of the IF-232 Interface. The 1488 needs a + and - supply.
Unregulated + and - 12vdc is just fine. Get the +5 vdc for the 1489 by putting a 7805 regulator on the +12 vdc supply. 100 mA.
is about the max you'll draw, so the smallest transformer you can find will still be plenty large. Don't forget to series up two of each gate to cancel the inversion that the 1480's produce.

ACC-1  Connector                  Use a 6 Pin DIN Connector.
                                         (Radio Shack $1.29)
Pin     Signal  Comments

1       Gnd     Signal Ground
2       TXD     Serial Data from Radio to Computer
3       RXD     Serial Data from Computer to Radio
4       CTS     Computer Ready;  (Radio Input)
5       RTS     Radio Ready;    (Radio Output)
6               No Connection

Pins 4 and 5 may be left Unconnected.

***** Command Description for Kenwood Computer Interface *****

                Auto Information
                The Radio Will Send the Status Info Automatically
                Whenever the Operator Manually Varies any Function
                on the Radio which is Covered in the IF; Command
                        Where   n = 0 for Auto Info OFF
                                    1 for Auto Info On

                The Status Information Will be Sent in the Form :
                        As defined in the IF; Command

                Display Memory
                This is a Factory Diagnostic Function
                and is of no practical use to the operator

                The Contents of the MPU Memory will be Read
                        Where   nnnn = MPU Address (0000 Thru FFFF (HEX))

                The Contents of the MPU Memory Will be Sent in the Form :
                        Where   nnnn = MPU Address (0000 Thru FFFF (HEX))
                              aa~~kk = Hex Number Pairs Of Next 16 Locations

                The Frequency or Memory Channel
                Will Decrement One Step

                Frequency VFO A / VFO B Request
                The Frequency in the Selected VFO Will be Read

                The Frequency Will be Sent in the Form:
                 FAggmmmkkkhhh;   or
                        Where    gg = GHz. Value
                                mmm = MHz. Value
                                kkk = kHz. Value
                                hhh =  Hz. Value

                Frequency VFO A / VFO B Select
                The VFO Selected Will be Set to the Frequency Defined
                        Where    gg = GHz. Value (May be sent As 00 or Spaces)
                                mmm = MHz. Value
                                kkk = kHz. Value
                                hhh =  Hz. Value

                Function Select
                The Function Defined Will be Selected
                        Where   n = 0 for VFO A
                                    1 for VFO B
                                    2 for MEMORY

                Identify Model Request
                The Model of the Radio Will be sent in the Form :
                        Where : n = 1 for a TS-940 (*)
                                n = 2 for a TS-811 (*)
                                n = 3 for a TS-711 (*)
                                n = 4 for a TS-440

                Read Information Request
                The Status Information Will be Sent in the Form :
                 IFggmmmkkkhhh     snnnzrx yytdfcp
                        Where   gg~~hhh = Value as defined in FA Command
                                      s = "+" or "-" Value of RIT/XIT
                                    nnn = Value of RIT/XIT (n.nn kHz.)
                                      z = "0"  (Not Used in TS-440)
                                      r = Value as defined in RT Command
                                      x = Value as defined in XT Command
                                     yy = Memory Channel No.
                                      t = 0 for Receive
                                          1 for Transmit
                                      d = Value as defined in MD Command
                                      f = Value as defined in FN Command  
                                      c = Value as defined in SC Command
                                      p = Value as defined in SP Command  

                Lock Knob
                The Manual Frequency Control Functions Will be Disabled
                        Where   n = 0 for Lock OFF
                                    1 for Lock ON

                Memory Channel Select
                The Memory Channel Defined Will be Selected
                        Where:  x = Don't Care   (Use "0" or Space)
                               mm = Memory Channel No. (00 thru 99)

                Mode Select
                The Mode Defined Will Be Selected
                        Where:  n = 1 for LSB
                                    2 for USB
                                    3 for CW
                                    4 for FM
                                    5 for AM
                                    6 for FSK

                Memory Read
                The Memory Channel Defined Will be Read
                        Where:  n = 0 for RX VFO
                                    1 FOR TX VFO (Split Channels Only)
                                x = Don't Care      (Use "0" or Space)
                               rr = Memory Channel No.    (00 thru 99)

                The Memory Information will be sent in the Form :
                 MRn rrggmmmkkkhhhdz    ;
                        Where:  n = 0 for RX VFO
                                    1 FOR TX VFO (Split Channels Only)
                               rr = Memory Channel No.    (00 thru 99)
                         gg~~hhh = Value as defined in FA Command
                                d = Value as defined in MD Command
                                z = "0"  (Not Used in TS-440)
                        (Note: Four trailing Spaces)

                Memory Write           
                The Memory Selected Will be Set to the Frequency Defined
                        Where:  n = 0 for RX VFO
                                    1 for TX VFO (Split Channels Only)
                                x = Don't Care  (Use "0" or Space)
                               rr = Memory Channel No.    (00 thru 99)
                          gg~~hhh = Value as defined in FA Command
                                d = Value as defined in MD Command
                                z = "0" (Not Used in TS-440)

                RIT/XIT Clear
                The RIT/XIT will be set to 0.00 kHz.

                RIT/XIT Down
                The RIT/XIT will Decrement by 0.01 KHz. (10 Hz.)

                RIT/XIT UP
                The RIT/XIT will Increment by 0.01 KHz. (10 Hz.)
Kenwood TS-440S (TS 440 S TS440S) increase the power by ALC control

This article also tells how to increase the power of the TS-440 by adjusting the internal ALC control. The procedure is applicable to other rigs.

Illustration captions:
  1. Remove 17 screws holding on the bottom and top covers. The bottom cover comes off, and the top cover is carefully removed and put next to the radio. It is till connected via the speaker wire.
  2. Gain access to the front of the unit by removing two top side screws and loosening two bottom side screws. This allows the front assembly to swing open.
  3. Remove the shiny silver control board protection plate. This requires removing two screws on the top and three screws on the bottom. Lift the plate out completely. Locate diode D-80 in the bottom left-hand corner. Snip it for all-band transmit.
  4. Now locate D-66 and snip. It adds 10 Hertz readout to your digital frequency display.
  5. Carefully reassemble the control plate using a magnetized tiny screwdriver to hold the five tiny screws in place. Don't pinch any wires. Also, close up the front and replace the top and bottom covers with 17 screws.
  6. Connect power. Depress A=B switch and turn on the power simultaneously. This resets the microprocessor for all-band transmit and 10 Hz frequency display.
Kenwood TS-440S (TS 440 S TS440S) with PIN-Diods

Hallo, ts440-owners!

Recently i read about an upgrade for the ts440 concerning the bandswitc-diods.
Originally, there are simple switching types built in. For better high level performance i decided to replace D2,3,4,5,6,7,...23,68 by the ECG553 PIN Diode.
The result was not so doubtless positive. i could not really confirm an advantage. unfortunately, i have no measuring equipment for determining the intercept point.
But on 40m , where i sometimes have problems using a 160/80/40/30/20m 5-band fullsize dipole, i still suffer intermodulation effects.
I can not really say, if it is much better after the replacement, but i'm sure, it isn't worse (hi).
Some remarkable progress was the usage of the built-in tuner in the receiving pass. that really helped espacially on the 10mc band to overcome the problems of interference.
But best results and a final solution i found in using an external preselector as described in the cq-dl several times.
That really did it! Of course you need to add on to cinch connectors at the rear panel.
It is no real problem.
so, my advice:
dodn't modificate the diods or use of the tuner for reception.
The result is too poor compared with that of an external preselector.
Kenwood TS-440S (TS 440 S TS440S) Operation with the MC-85

With some TS-440S transceivers, insufficient modulation may occur when the MC-85 compression switch is turned on. This may be caused by too much of a voltage drop across resistor R172 on the IF unit of the transceiver . If this is found to be the case, change the resistor from 1K ohm to 100 ohms.

Required part
100 Ohm, 1/6 Watt resistor (RD14CB2C101J)


  1. Disconnect the power supply and antenna from the transceiver.

  2. Using a #2 Phillips screw driver, remove the 9 screws from the top cover of the transceiver. Remove the cover and unplug the speaker wire.

  3. Locate resistor R172 on the component side of the IF board (Figure 1).

  4. Using a #1 Phillips screw driver, remove the 7 screws that secure the IF unit to the chassis of the transceiver.

  5. Pull the board up and rotate it towards the front of the transceiver to expose the foil side of the board.

  6. Desolder and remove resistor R172 from the board.

  7. Install and solder the 100 ohm resistor in place of R172.

  8. Assemble the transceiver by reversing steps 1 - 5.


Figure 1

This modification may be covered under warranty.
Time required for this modification is 0.5 hrs or less.

Kenwood TS-440S (TS 440 S TS440S) Notch filter low frequency improvements

The low frequency attenuation characteristics of the notch filter can be improved by reducing the input level to the notch filter chip (IC1). To compensate for the loss of input level, the amount of negative feedback to the audio amplifier (IC7) will need to be reduced. This modification is already incorporated in all models beginning with serial number 704XXXX.

Required parts:

120K Ohm, 1/6 Watt resistor ........ RD14CB2C124J
390 Ohm,  1/6 Watt resistor ........ RD14CB2C391J
  1. Disconnect the power supply and antenna.

  2. Using a #2 Phillips screw driver, remove the 9 screws from the top cover. Remove the top cover from the transceiver and unplug the speaker wire.

  3. Locate resistors R86 and R229 on the component side of the IF board (Figure 1).

  4. Using a #1 Phillips screw driver, remove the 7 screws that secure the IF unit to the chassis of the transceiver.

  5. Pull the board up and rotate it towards the front of the transceiver to expose the foil side of the board.

  6. Desolder and remove both resistors from the board.

  7. Install and solder a 102K ohm resistor in place of R86.

  8. Install and solder a 390 ohm resistor in place of R229.

  9. Assemble the transceiver by reversing steps 1 - 5.


Figure 1

This is an optional change that may not be performed under warranty.
Time required for this modification is 0.5 hrs or less.


Kenwood TS-440S (TS 440 S TS440S) Protecting Q33


If pin 7 (RL) of the remote connector is accidently connected to ground, current from the 14 volt line (14L) will damage transistor Q33 on the IF unit. This will prevent the radio from transmitting. To protect Q33, a 4.7 ohm resistor should be installed in series with the RL line on the foil side of the IF board. In the event that pin 7 is connected to ground, the resistor will open, but the transceiver will still be capable of transmitting.

Required part:
4.7 Ohm, 1/6 Watt resistor ........ RD14CB2C4R7J

  1. Disconnect the power supply and antenna from the transceiver.

  2. Using a #2 Phillips screw driver, remove the 9 screws from the top cover of the transceiver. Remove the cover and unplug the speaker wire.

  3. Locate connector 19 on the IF unit.

  4. Using a #1 Phillips screw driver, remove the 7 screws that secure the IF unit to the chassis of the transceiver.

  5. Pull the board up and rotate it towards the front of the transceiver to expose the foil side of the board.

  6. On the foil side of the board, locate the trace that is connected to pin 3 (brown wire) of connector 19.

  7. Using a craft knife, cut the trace comming from pin three so as to open the foil trace.

  8. Solder the 4.7 ohm resistor across the now open trace (i.e. in series with the trace).

  9. Assemble the transceiver by reversing steps 1 - 5.


This is an optional change that may not be covered under warranty.
Time required for this modification is 0.5 hrs or less.

Kenwood TS-440S (TS 440 S TS440S) Case Screws binding in the heat sink

Occassionally a case screw that fastens to the heat sink of the TS-440S will cross thread or bind when it is being inserted or removed. Binding may be caused by tooling marks on the screw or by burrs on the tapped threads in the heat sink. When a screw starts to bind, DO NOT TRY TO FORCE IT! as this may cause the head to shear off. If the screw is being removed and it starts to bind, return the transceiver to KENWOOD. Do not make attempts to remove the screw. In addition, if a transceiver is being brought to you with a scrw sheared off, return the unit to KENWOOD. Do not attempt to drill out the screw.

If a screw starts to bind when it is being installed, carefully back it out. Inspect the screw for marks or burrs and replace it if it is questionable. Since the threads in the heat sink may be causing the screw to bind, they should be cleaned by running a 3 x 0.5 mm tap into each hole.
The tap is inexpensive and can be obtained at may of the larger hardware stores.

To avoid cross threading, make sure the covers are properly aligned when they are being installed. Proper alignment means that there is a clear path for the screw to turn into the heat sink.
This assures that the screw does not rub against the case and result in it turning into the heat sink at an angle.

Kenwood TS-440S (TS 440 S TS440S) RX Audio Mods

Here's some easy modifications to improve the rx audio fidelity of Kenwood TS-440's. All references below are to the IF board component designations.
  • Increase C60 to a .47uf or 1 uf. This will increase low frequency response on all modes.

  • Decrease C51 to .01 uf. This will increase high frequency response on SSB/CW.

  • Try removing R263 (tacked on the bottom of the board on my early production unit). This will lower in amplitude the audio coming out of the detectors and improved the smoothness (a real technical term) of the audio, especially on AM signals.
And, of course, I take no responsibilty for anything you do to your radio. Be careful. The IF board on the 440' is about the easiest one to get at.
Kenwood TS-440S (TS 440 S TS440S) Bandscope-Schaltung


Zum Herausführen der 2. ZF von 8,83 MHz genügt ein 33pf Keramikkondensator An Diode D34/ D36 auf der IF-Unit (X44-1680-00) und ein Stückchen RG-174 Coaxleitung.

Eine genaue Anleitung findet ihr in der Clubzeitschrift des DARC e.V.
CQDL 11-1991 S.673
Bandscope-Schaltung mit TS-440S und Monitor SM-220

Da ich keine zusätzlichen Löcher bohren wollte, habe ich entgegen der Anleitung die paar Schrauben mehr gelöst, und die unbeschaltete Chynchbuchse auf der Rückseite benutzt.
Die Platine mit den Chynchbuchsen ist mit drei Schrauben befestigt, die Leitungen sind mit Steckverbindern angeschlossen.


Kenwood TS-440S (TS 440 S TS440S) Modifications in FM mode


FM rx-modification

The TS-440 FM receiver seems to be constructed for 25kHz steps. Using 10kHz steps, the bandwidth is much too wide.

Using the 8.83 MHz filter on the RF board, which is normally bypassed by FM solved this problem and I got a very useful FM rig, even with the original F-Type filter.

Required parts: 2 diodes 1N4148

  1. Disconnect the power supply and antenna from the transceiver.
  2. Using a #2 Philips screw driver, remove the screws from the bottom cover. Remove the bottom cover from the transceiver.
  3. Locate resistor R59 and capacitor C131 on the component side of the RF board.
  4. Using a #1 Philips screwdriver, remove the screws that secure the RF unit to the chassis of the transceiver.
  5. Remove all plugs still keeping the board in position.
  6. Pull the board up and rotate it towards the front of the transceiver to expose the foil side of the board.
  7. Find the junction of R59 and C131 opposite their ground connection.
  8. Disconnect R59 from C131 by scratching the track with a sharp knife.
  9. Install and solder diode A with anode connected to R59 and cathode connected to C131.
  10. Install and solder diode B with anode connected to R58/C131 and cathode connected to C131.
  11. Remove resistor R57.
  12. Reassemble the transceiver by reversing the steps 1 to 6.
Model No Manufacturer Description  

The following parts are available for the model listed above. To order parts, enter a quantity and click "Add to Cart".

Part No Description Availability Price   QTY
 E07-1351-05 13 PIN DIN PLUG DISCONTINUED     
Replacement Available - See Below    
 E07-1351-15 13 PIN DIN PLUG NOT IN STOCK  $22.82 
 E04-0157-05 ANT RECPT IN STOCK  $2.64 
 X57-1150-00 AT UNIT DISCONTINUED     
 E08-0671-05 DC JACK IN STOCK  $2.71 
Replacement Available - See Below    
 E30-2065-45 DC POWER CORD NOT IN STOCK  $62.09 
 F09-0410-04 FAN BLADE NOT IN STOCK  $6.59 
 A20-2556-03 FRONT PANEL ASSY NOT IN STOCK  $27.79 
 X60-1300-00 IF UNIT ASSY NOT IN STOCK  $427.00 
 G02-0505-05 KNOB FIXED SPRING IN STOCK  $0.95 
Replacement Available - See Below    
 K29-0758-24 KNOB, POWER NOT IN STOCK  $3.54 
 K29-0741-34 KNOB, RF IN STOCK  $4.16 
 B30-0817-15 LAMP (METER) IN STOCK  $4.07 
Replacement Available - See Below    
 W09-0599-05 BATTERY, LITHIUM IN STOCK  $6.00 
 B31-0657-05 METER DISCONTINUED     
 T91-0352-15 MICROPHONE NOT IN STOCK  $59.95 
 T42-0302-05 MOTOR, FAN NOT IN STOCK  $32.75 
 X50-2050-00 PLL UNIT (PCB ) DISCONTINUED     
 R24-9405-05 SQL CONTROL NOT IN STOCK  $16.00 
Replacement Available - See Below    
 S40-2437-15 POWER SWITCH NOT IN STOCK  $12.99 


Kenwood  parts from Kenwood Parts


Qty. Part Number Description Alternate Part Price
 1SV153   (L20) VARICAP TS-440S      $1.78 
Discont.  AN7808   (D) IC TS-440S TS-140S TS-680S   AN7808F   $6.42 
 C90-0822-05   47UF 16V TS-440S      $1.63 
 CC45SL2H331J   CERAMIC 330PF TS-440S      $1.38 
Discont.  DSP-301NF   (D) THERMISTOR TS-440S KRC2001   DSP-301N-BF   $2.77 
 E40-3237-05   SPEAKER CONN. (2P) TK-805 TS-440S TS-850S TM-251A TS-2000 TS-2000X      $0.83 
 E40-3238-05   PIN CONNECTOR 3P TS-2000 TS-2000X TS-850S TS-440S      $0.95 
 E40-3239-05   TS-440S TS-850S 5P CONN.      $1.21 
 L40-1021-13   INDUCTOR(1MH) TK-720 TS-440S      $2.82 
 L40-2792-14   TK-802R TK-702R TS-950SD TS-440S INDUCTOR 2.7UH TS-950SDX      $1.38 
 TC4030BP   IC TS-440S      $6.31 
 TC4069UBP   TS-440S IC      $6.12 
Discont.  27C128-25JAH3   IC TS-440S      $40.66 
 2SA562TM   TRANSISTOR TS-440S   2SB698(F,G)   $1.10 
 2SC2075   TRANSISTOR TS-430S TS-440S TS-850S      $7.93 
 2SC2879   TS-440S TS-850S FINAL TRANS.   2SC2879(O,Y)   $45.00 
 2SK125-5   (L10) FET (SI 300MW 100MHZ) TS-440      $4.65 
Discont.  5T41L   (D) THERMISTOR TS-440S   5T-41L   $0.00 
Discont.  A01-0998-02   (D) TS-440S TOP CASE      $42.06 
Discont.  A01-0999-12   (D) TS-440S BOTTOM CASE      $338.82 
Discont.  A20-2556-03   (L1) FRONT PANEL TS-440S      $27.79 
Discont.  A40-0617-03   (D) BOTTOM PLATE TS-440S      $8.04 
Discont.  B31-0657-05   TS-440S METER      $52.56 
Discont.  B40-3625-04   (D) TS-440S   B40-3625-14   $1.48 
Discont.  B40-3625-14   NAME PLATE TS-440S      $1.46 
 B41-0338-04   TS-440S NAME PLATE      $0.81 
 B42-2422-04   TS-440S NAME PLATE      $2.49 
Discont.  B43-1065-04   (D) BADGE TS-440SA      $4.07 
 B50-8048-30   TS-440S OWNERS MANUAL (XEROX COPY ONLY)      $20.00 
Discont.  B50-8153-20   (D) TS-440S MULTI LANGUAGE O/M      $15.00 

Qty. Part Number Description Alternate Part Price
Discont.  B51-1919-00   (S) S/M TS-440S PS-430 PS-50 MB-430      $38.00 
 BX6124   IC TS-440S      $24.08 
 BX7191   IC TS-440S      $15.25 
 C90-2035-05   TS-440S E.CAP, 100UF/16WV      $0.99 
Discont.  C91-0125-05   (D) TS-440S   C91-1067-05   $0.00 
 C91-0714-05   TS-440S SL, 7PF      $0.33 
 C91-0727-05   CAPACITOR 18PF (SL) TS-440S      $0.33 
 C91-1063-05   TS-440S CERAMIC,0.0033UF      $0.59 
 C91-1064-05   TS-440S CERAMIC, 0.0039UF      $0.62 
Discont.  C91-1065-05   TS-440S CERAMIC, 0.0068UF      $0.62 
 C91-1067-05   TS-440S 0.0027UF      $0.59 
 CC45RH1H680J   CERAMIC 68PF TS-440S      $0.59 
Discont.  CC45TH1H390J   TS-440S CERAMIC 39PF   CC45CH1H390J   $0.91 
Discont.  CC45UJ1H470J   TS-440S CERAMIC 47PF      $0.59 
Discont.  CC45UJ1H680J   TS-440S CERAMIC 68PF      $0.62 
 CK73FB1H123K   CHIP CAPACITOR TS-440S      $0.65 
 DAN401   DIODE TS-440S      $3.91 
Discont.  DSP-301N   (D) TS-440S   DSP-301N-BF   $0.00 
 DSP-301N-BF   SURGE ABSORBER TS-440S KRC2000A      $2.18 
 E02-2001-05   TS-440S IC SOCKET, 28P      $5.16 
 E06-0656-05   TS-440S 6 PIN DIN SOCKET      $4.68 
 E06-0754-05   TS-440S 7 PIN DIN SOCKET      $4.92 
 E06-1351-05   TS-140S TS-680S TS-440S DIN SOCKET 13P ACC2 CN28      $8.92 
 E11-0413-05   TS-440S R-600 US JACK PHONE      $7.56 
 E11-0414-05   3.5D PHONE JACK (3P) TS-2000 TS-2000X TS-440S R-2000      $2.85 
 E11-0418-05   JACK TS-440S TS-680S      $6.94 
 E13-0362-05   TS-440S PHONO JACK      $7.20 
Discont.  E23-0473-04   (D) TERMINAL TS-440S      $2.56 
Discont.  E30-1638-05   (D) TS-430S TS-440S TS-130S TS-120S TS-180S   E30-2065-25   $24.95 
 E31-3161-05   TS-440S 13P CONNECTING CORD      $2.56 

Qty. Part Number Description Alternate Part Price
 E31-3162-05   TS-440S 12P CONNECTING CORD      $2.56 
 E31-3163-05   TS-440S 9P CONNECTING CORD      $1.70 
 E31-3164-00   TS-440S CONNECTING WIRE      $10.59 
 E31-3165-05   TS-440S CONNECTING WIRE      $1.28 
 E31-3167-00   TS-440S CONN CORD ASSY      $65.59 
 E31-3168-00   TS-440S CONNECT. CORD W/PLUG      $10.51 
 E31-3169-00   TS-440S CONN CORD ASSY      $46.59 
 E31-3170-05   TS-440S CONNECTING WIRE      $3.01 
 E31-3173-00   TS-440S CONNECTING WIRE      $4.19 
 E31-3174-00   TS-440S CONNECTING WIRE      $20.44 
 E31-3177-15   AT-440 TS-440S CONN. WIRE 8P TO 4P & 2P      $10.81 
 E31-3178-00   TS-440S CONNECTING WIRE      $41.12 
 E31-3183-00   TS-440S CONNECTING WIRE      $7.73 
 E31-3184-00   TS-440S CONNECTING WIRE      $23.44 
 E40-0675-05   TS-440S MINI CONN. 6P FEMALE      $0.71 
 E40-3240-05   PIN CONNECTOR 5P TS-2000 TS-2000X TS-440S      $1.25 
 E40-3241-05   6P CONNECTOR TS-440S KCH-4      $1.15 
 E40-3242-05   TS-440S TS-850S 7P CONN.      $1.34 
 E40-3243-05   TS-440S PIN CONNECTOR, 8P      $1.52 
Discont.  E40-5066-05   TS-440S PIN CONNECTOR, 9P      $1.70 
 E40-5068-05   TS-440S PIN CONNECTOR      $1.91 
Discont.  F01-0937-05   (D) TS-440S HEAT SINK   F01-0937-15   $75.33 
Discont.  F01-0937-15   TS-440S HEAT SINK      $110.00 
 F02-0423-04   TS-440S HEAT SINK      $5.76 
Discont.  F11-1004-03   TS-440S SHIELD COVER (CONT.)   F11-1004-13   $7.20 
 F11-1004-13   TS-440S R-5000 SHIELDING CASE      $6.00 
 FIP13BM7   (L1) LCD TS-440S R-5000      $40.54 
Discont.  G10-0638-04   (D) CUSHION TS-440S   G10-0638-14   $1.04 
 G10-0638-14   ELECTRIC INSULATION TS-440 R-5000      $0.93 
 G10-0640-04   TS-440S MASK FOR VOX SW      $0.57

Qty. Part Number Description Alternate Part Price
Discont.  H01-4683-04   (D) INSIDE CARTON TS-440S      $7.42 
Discont.  H03-2278-04   (D) TS-440S W/AT OUTSIDE BOX   H03-2278-14   $3.00 
Discont.  H03-2278-14   TS-440S W/AT CARTON OUTSIDE      $3.00 
Discont.  H03-2279-04   (D) TS-440S   H03-2279-14   $3.00 
 H03-2279-14   TS-440S W/O AT CARTON (OUTSIDE)      $5.42 
Discont.  H10-2615-02   (D) BUFFER (F) TS-440S      $2.00 
Discont.  H10-2616-02   (D) BUFFER (R) TS-440S      $3.00 
 H10-4683-04   (D) TS-440S      $4.50 
 H12-1390-03   (D) TS-440S      $1.50 
 H12-1391-04   (D) TS-440S      $2.00 
 H20-1425-03   TS-440S PLASTIC BAG   H20-1410-03   $3.80 
 ITT310TE   (L20) DIODE TS-440S R-2000 TS-670 TH-21A TH-21AT      $3.71 
 J02-0440-04   FOOT (METAL BAR) TS-2000 TS-2000X TS-440S TS-570D TS-570DG TS-570S      $7.83 
 J02-0441-05   FOOT (SIDE) TS-50S TS-440S TS-570D TS-570DG TS-570S      $1.10 
 J21-4177-04   TS-440S BRKT FOR X53-1450-11      $1.70 
 J31-0141-04   COLLAR (MIC) TS-2000 TS-2000X TS-50S TS-440S TS-820      $1.49 
 J32-0792-04   STUD TS-440      $1.87 
 J32-0794-04   TS-440S      $1.96 
 J32-0795-04   TS-440S      $3.57 
Discont.  K01-0416-05   TS-850S TS-950SD TS-440S TS-790ATS-140S TS-680S R-5000 HANDL   K01-0420-05   $8.42 
 K21-0778-02   MAIN KNOB TS-440S      $36.39 
 K21-0778-05   TS-440S KNOB, MAIN   K21-0778-02   $36.39 
 K23-0782-04   KNOB TS-440 R-5000      $3.57 
Discont.  K27-0426-04   (D)1/23/92. TS-440S BAND BAR (UP & DOWN)   K27-0426-14   $5.76 
 KNOB440-SPLIT   TS-440S SPLIT      $1.00 
 KNOB440-TFSET   TS-440S T-F SET      $1.00 
 KNOB440-XIT   TS-440S XIT      $1.00 
 KNOB5000-1MHZ   R-5000 TS-440S 1MHZ      $1.00 
 KNOB5000-A/B   R-5000 TS-440S A/B      $1.00 
 KNOB5000-A=B   R-5000 TS-440S A=B      $1.00

Qty. Part Number Description Alternate Part Price
 KNOB5000-AM   R-5000 TS-440S AM      $1.00 
 KNOB5000-CLEAR   R-5000 TS-440S CLEAR      $1.00 
 KNOB5000-CW   R-5000 TS-440S CW      $1.00 
 KNOB5000-ENT   R-5000 TS-440S ENT      $1.00 
 KNOB5000-FM   R-5000 TS-440S FM      $1.00 
 KNOB5000-FSK   R-5000 TS-440S FSK      $1.00 
 KNOB5000-HF/VHF   R-5000 TS-440S HF/VHF      $1.00 
 KNOB5000-MIN   R-5000 TS-440S MIN      $1.00 
 KNOB5000-MV   R-5000 TS-440S MV      $1.00 
 KNOB5000-PG   R-5000 TS-440S PG      $1.00 
 KNOB5000-SCAN   R-5000 TS-440S SCAN      $1.00 
 KNOB5000-USB   R-5000 TS-440S USB      $1.00 
 KNOB5000-VFO/M   R-5000 TS-440S VFO/M      $1.00 
 L19-0362-05   TS-440S TRANSFORMER      $6.36 
 L19-0363-05   TS-440S TS-850S TRNSFRMR.      $29.39 
Discont.  L32-0666-15   OSCILLATION COIL TS-440S   L32-0666-05   $4.17 
 L33-0232-05   TS-440S CHOKE C01L 1UH      $1.56 
 L34-1162-05   TS-440S COIL      $1.06 
 L34-1163-05   TS-440S COIL      $1.06 
 L34-2266-05   TS-440S COIL      $4.57 
 L34-2267-05   TS-440S COIL      $4.57 
 L34-2268-05   TS-440S COIL      $4.57 
 L34-2269-05   TS-440S COIL      $3.57 
 L34-2270-05   TS-440S COIL      $3.57 
 L34-2271-05   TS-440S COIL      $4.57 
 L34-2272-15   TS-440S COIL      $4.57 
 L34-2273-05   TS-440S COIL      $4.57 
 L34-2274-05   TS-440S COIL      $4.57 
 L34-2276-05   TS-440S COIL      $4.57 
 L34-2277-05   COIL TS-440S      $4.57 

Qty. Part Number Description Alternate Part Price
 L34-2278-05   TS-440S COIL      $4.19 
 L34-2283-05   TS-440S COIL      $4.57 
 L34-2284-05   TS-440S COIL      $3.57 
 L34-2285-05   TS-440S COIL      $4.70 
 L34-2287-05   TS-440S COIL      $4.57 
 L34-2288-05   TS-440S COIL      $4.57 
 L34-2289-05   TS-440S COIL      $4.57 
 L34-2290-05   TS-440S COIL      $4.19 
 L34-2291-05   TS-440S COIL      $3.86 
 L34-2292-05   TS-440S COIL      $4.70 
Discont.  L34-3144-15   (D) COIL TS-440S   L39-1229-05   $10.71 
Discont.  L34-3145-15   TS-440S COIL   L39-1228-05   $12.10 
 L34-3146-05   TS-440S COIL      $9.32 
 L34-3147-05   TS-440S COIL      $6.94 
 L34-3148-05   TS-440S COIL      $6.94 
 L34-3149-05   TS-440S COIL      $6.94 
 L34-3150-05   TS-440S COIL      $6.94 
 L34-3151-05   TS-440S COIL      $6.94 
 L34-3152-05   TS-440S COIL      $6.94 
 L34-3153-05   TS-440S COIL      $6.94 
 L34-3154-05   TS-440S COIL      $6.94 
 L34-3156-05   TS-440S COIL      $2.02 
 L34-3157-05   TS-440S COIL      $1.06 
 L34-3158-05   TS-440S COIL      $1.06 
 L39-0422-05   TS-440S COIL      $7.32 
 L39-0423-05   TS-440S COIL      $7.92 
 L39-0424-05   TS-440S TS-850S COIL      $7.32 
 L39-1228-05   TS-440S COIL      $10.02 
 L39-1229-05   COIL TS-440S      $10.71 
 L40-1511-13   INDUCTOR TS-430S TS-440S      $1.19 

Qty. Part Number Description Alternate Part Price
 L40-1592-14   TS-440S      $1.20 
 L40-1892-14   TS-440 FERRI-INDUCTOR 1.8UH      $1.20 
 L40-2201-13   INDUCTOR TS-440S      $1.14 
 L40-2292-14   TS-440 FERRI-INDUCTOR 2.2UH      $0.77 
 L40-2782-14   INDUCTOR TS-440S      $1.14 
 L40-3311-14   COIL TS-440S      $1.19 
 L40-3982-14   TS-440S 0.39UH      $1.20 
 L40-4701-13   TS-430S TS-440S INDUCTOR      $1.20 
 L40-6825-04   6.8MH FERR-INDUCTOR TS-440S TW-4000      $2.06 
 L71-0208-15   FILTER YK-88S CW 2.4KHZ R-5000 TS-440S TS-120S      $92.95 
Discont.  L71-0211-05   (D) CW FILTER 500HZ ( YK-88C ) TS-440S TS-430S TS-830S      $104.95 
Discont.  L71-0220-05   (D) CW FILTER 1.8KHZ YK-88SN TS-440S TS-430S TS-530S R-5000      $99.95 
Discont.  L71-0221-05   (D) FILTER, CW 270HZ YK-88CN TS-440S TS-430S TS-830S      $104.95 
 L71-0259-05   TS-440S X'TAL FILTER,45,05 MHZ      $46.39 
 L71-0260-05   TS-440S X'TAL FILTER,8.83 MHZ      $21.76 
 L72-0355-05   TS-440S CERAMIC FILTR,CF1455IT      $7.93 
 L72-0356-05   TS-440S CERAMC FILTR,CFJ455K14      $79.18 
Discont.  L77-1299-05   (L2) CRYSTAL 36MHZ TS-440S      $21.17 
Discont.  L77-1302-05   (D) CRYSTAL 8.375MHZ TS-440S   L77-1302-15   $18.81 
 L78-0015-05   TS-440S RESONATOR, 2.45MHZ      $5.40 
 L78-0019-05   TS-440S CERAMIC OSC,1.99 MHZ      $6.00 
 LM2931Z-5.0   IC TS-440S      $6.82 
 M54460L   IC TS-440S      $11.74 
 M74LS00P   IC TS-440S      $3.05 
 M74LS123P   IC TS-440S      $5.29 
Discont.  MA858   DIODE TS-440S      $1.14 
 MB87006   IC TS-440S      $21.83 
Discont.  MBM27128-25JA1   (D) IC TS-440S   27C128-25JAH3   $0.00 
Discont.  MBM27128-25JA2   (D) IC TS-440S   27C128-25JAH3   $0.00 
Discont.  MBM27128-25JA3   (D) IC TS-440S   27C128-25JAH3   $0.00 


Qty. Part Number Description Alternate Part Price
Discont.  MBM27C128-25JA3   (D) IC TS-440S   27C128-OR25JAH   $0.00 
Discont.  MV-5T   VARISTOR TS-440S TS-950SD TS-680S      $4.59 
 N09-0699-05   TS-440S      $0.33 
 N19-0601-14   TS-440S FLAT WASHER      $1.04 
 N19-0637-04   WASHER,FLAT(PANEL) TS-440S TS-690S TS-450S      $1.23 
 N30-4014-41   TS-440S SCREW      $0.07 
Discont.  N30-4014-46   (D) SCREW TS-440S   N30-4014-41   $0.00 
 NJM2903S   TS-440S IC      $4.09 
 NJM2904S   IC TS-440S      $5.80 
 R12-0435-05   TS-440S TRIM POT      $2.35 
 R12-2414-05   TS-440S TRIM POT, 5K      $2.35 
 R12-3408-05   POT (VX GAIN) 47KB TS-120 TS-440S (VR12)      $3.14 
 R12-3435-05   TRIM POT 30K TS-440S      $0.99 
Discont.  R19-3420-05   (L1) POT (AF/RF) TS-440S TS-670      $12.00 
 R24-9405-05   (L10) POT (SQ/NOTCH) TS-440S      $16.62 
Discont.  R90-0454-05   MULTIPLE COMPONENTS RESIS TS-440S      $1.10 
 R90-0596-05   TS-440S 100PFX8      $4.47 
 RC05GF2H510J   TS-440S 51 OHM 1/2W SOLID      $0.41 
 RD14CB2C4R7J   TS-440S 3W      $0.11 
 S01-2425-05   (L2) ROTARY SW TS-440S VFO-230      $11.90 
 S31-0402-05   TS-440S SLIDE SWITCH      $12.89 
 S31-4405-05   TS-440S SLIDE SWITCH      $5.76 
Discont.  S40-2434-05   (D) PUSH SW FULL BK TS-440S      $6.36 
 S40-2441-15   PUSH SW (RIT) TS-440S      $5.04 
 S51-1414-05   ANTENNA RELAY TS-930S TS-440S      $14.54 
 S51-1420-05   RELAY TS-50S AT-250 TS-440S      $11.90 
 S51-1429-05   RELAY (ANTENNA) TS-140S TS-440S      $14.50 
 S51-1432-05   TS-440S RELAY      $10.61 
 S51-2417-05   RELAY TS-440S      $16.36 
Discont.  S59-0436-05   (D) KEY BOARD ASSY TS-440S      $94.74 


Qty. Part Number Description Alternate Part Price
Discont.  S76-0402-05   TS-440S RELAY   S51-1432-05   $10.21 
Discont.  SN7404N   (D) IC TS-440S   HD74LS04P   $0.00 
 SN74LS123N   TS-440S      $6.00 
Discont.  T91-0331CORD   TM-201A TS-440S MC-43S MIC CORD ASSY TS-950SD      $20.90 
Discont.  T91-0352-05   (D) TS-440S MIC MC-42S   T91-0352-15   $60.30 
Discont.  T91-0352-15   MIC ( MC-43S ) 8P TS-2000 TS-2000X TS-440S TS-950SD TS-570D TS-570DG TS-570S   T91-0352-35   $59.95 
Discont.  TMP82C55AP-2   IC TS-440S KPT-20   MSM82C55A-2RS   $17.71 
 UPD7800G   IC TS-440S      $50.13 
 UZ3.0B   ZENER DIODE TS-680S TS-440S KSC-4 BC-7      $0.88 
 UZ6.2BL   DIODE TS-440S      $0.87 
Discont.  W02-0373-25   (L2) TS-440S ROTARY ENCODER      $58.65 
 X41-1610-00   SW UNIT TS-440S      $208.47 
Discont.  X41-1610-00A/14   TS-440S SW.UNIT(A/14 ONLY) CAR,MIC GAIN UNIT      $35.00 
Discont.  X41-1610-00B/14   (D) SW UNIT (B/14, IF,RIT) TS-440S      $35.00 
 X41-1610-00C/14   TS-440S SW.UNIT(C/14 ONLY) VOX,DELAY UNIT      $28.00 
 X41-1610-00D/14   TS-440S SW.UNIT(D/14 ONLY) EARPHONE UNIT      $18.00 
Discont.  X41-1610-00E/14   (D) SW UNIT (E/14-MIC) TS-440S      $22.00 
 X41-1610-00F/14   TS-440S SW.UNIT(F/14 ONLY) SELECTIVITY UNIT      $22.00 
 X41-1610-00G/14   TS-440S SW.UNIT(G/14 ONLY) EXT.SP. UNIT      $21.96 
 X41-1610-00H/14   TS-440S SW.UNIT(H/14 ONLY) PWR. SUPPLY UNIT      $26.38 
 X41-1610-00I/14   TS-440S SW.UNIT(I/14 ONLY) AVR UNIT      $45.00 
 X41-1610-00J/14   TS-440S SW.UNIT(J/14 ONLY) FILTER UNIT      $19.31 
 X41-1610-00K/14   TS-440S SW.UNIT(K/14 ONLY) SUB-AVR UNIT      $27.00 
 X41-1610-00L/14   TS-440S SW.UNIT(L/14 ONLY) VOX UNIT      $15.00 
 X41-1610-00M/14   TS-440S SW.UNIT(M/14 ONLY) FSK UNIT      $19.00 
Discont.  X41-1610-00N/14   (D) ANT RELAY UNIT (N/14) TS-440S      $30.00 
Discont.  X44-1680-00   (D) RF UNIT TS-440S      $377.39 
Discont.  X45-1470-00   (D) FINAL UNIT TS-440S      $336.51 
Discont.  X50-2050-00   TS-440S PLL UNIT      $317.78 
Discont.  X51-1340-00   (D) FILTER UNIT TS-440S      $206.96 

Qty. Part Number Description Alternate Part Price
Discont.  X53-1450-00   (D) CONTROL UNIT PCB ASS'Y TS-440S      $229.54 
 X53-1450-11   CONTROL UNIT TS-440S      $223.01 
Discont.  X54-1870-00   (D) DISPLAY UNIT TS-440S      $165.76 
Discont.  X54-1870-00A/4   TS-440S DISPLAY UNIT (A/4)      $89.58 
 X54-1870-00B/4   TS-440S DISPLAY UNIT (B/4)      $21.00 
 X54-1870-00C/4   TS-440S DISPLAY UNIT (C/4)      $25.20 
 X54-1870-00D/4   TS-440S DISPLAY UNIT (D/4)      $19.22 
 X57-1150-00   (D) AT UNIT TS-440S      $310.91 
Discont.  X59-1060-00   SIDE TONE UNIT TS-440S TS-450S TS-690S      $15.72 
Discont.  X59-1070-00   SELECTIVITY UNIT TS-440S      $13.99 
 X59-1080-00   SUB UNIT (VOX) TS-440S TS-850S TS-450S TS-690S      $18.99 
Discont.  X60-1300-00   (D) IF UNIT TS-440S      $427.24 
Discont.  E31-0431-15   CONN. WIRE W/PLUG TS-120S TS-440S      $4.66 
 K23-0712-04   (L2) VOX KNOB TS-120S TS-440S TS-450S TS-690S      $1.20 
Discont.  L19-0361-05   (D) TRANSFORMER TS-440S      $8.82 
 N30-2608-41   SCREW M2.6X8 TS-440S      $0.10 
Discont.  R19-3423-05   (L1) POTENTIOMETER (CAR MIC) TS-440S      $11.60 
 KNOB5000-LSB   R-5000 TS-440S LSB      $1.00 
Discont.  TMP8255AP-5   (D) IC TS-440S   MSM82C55A-2RS   $32.02 
Discont.  CC45SH1H470J   (D) CERAMIC 47PF 50V TS-440S      $0.39 
 KNOB440-RIT   TS-440S RIT      $1.00 
 E30-2065-25   CORD,DC ( PG-2S ) TS-430S TS-440S TS-130S TS-180S   E30-2065-45   $62.09 
Discont.  E30-2065-35   CORD,DC ( PG-2S ) TS-430S TS-440S TS-130S TS-180S TS-790S TS-680S TS-440S   E30-2065-25   $0.00 
 E30-2065-45   CORD,DC ( PG-2S ) TS-430S TS-440S TS-130S TS-180S TS-790S TS-680S TS-440S   E30-2065-25   $62.09 
Discont.  KB262   (D) VARISTOR TS-440S      $0.00 
 T91-0352-35   MIC ( MC-43S ) TS-2000 TS-2000X TS-440S TS-950SD TS-570D   T91-0352-15   $59.95 






































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