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.

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.
 

   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
 

 
                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.

        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.)
 

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.

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

                                          PTT

       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.

     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-60 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
                ________________
AIn; 
                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
                ______________
DMnnnn;
                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 :
                 DMnnnn-aabbccddeeffgghhiijjkk;
                        Where   nnnn = MPU Address (0000 Thru FFFF (HEX))
                              aa~~kk = Hex Number Pairs Of Next 16 Locations


                Down
                ____
DN;
                The Frequency or Memory Channel
                Will Decrement One Step


                Frequency VFO A / VFO B Request
                _______________________________
FA;
FB;
                The Frequency in the Selected VFO Will be Read

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


                Frequency VFO A / VFO B Select
                ______________________________
FAggmmmkkkhhh;
FBggmmmkkkhhh;
                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
                _______________
FNn;
                The Function Defined Will be Selected
                        Where   n = 0 for VFO A
                                    1 for VFO B
                                    2 for MEMORY

                Identify Model Request
                ______________________
ID;
                The Model of the Radio Will be sent in the Form :
                 ID00n;
                        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
                ________________________
IF;
                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
                _________
LKn;
                The Manual Frequency Control Functions Will be Disabled
                        Where   n = 0 for Lock OFF
                                    1 for Lock ON


                Memory Channel Select
                _____________________
MCxmm;
                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
                ___________
MDn;
                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
                ____________
MRnxrr;
                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           
                ____________
                 MWnxrrggmmmkkkhhhdzxxxx;
                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
                _____________
RC;
                The RIT/XIT will be set to 0.00 kHz.


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


                RIT/XIT UP
                __________
RU;
                The RIT/XIT will Increment by 0.01 KHz. (10 Hz.)

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.

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)

PROCEDURE:

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.

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

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.

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

If pin 7 (RL) of the remote connector is accidentally 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 coming 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.
 

Occasionally 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.
 

• 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 responsibility for anything you do to your radio. Be careful. The IF board on the 440' is about the easiest one to get at.

73/Dave n2fam@ka3fmo.pa
 

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.

Caution

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).

10. 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.
    
     
11. Install the ROM in the board and solder it in place.
    
     
12. 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.
 

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 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.
 

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.
 

(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.
 

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 transmit on 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.