Kenwood TS 820S Diagram

Modifications for the Kenwood TS-820

TS-820 Fix the problem with the display

Here is somthing you can do if your digital display on the kenwood ts-820 is giving you

a problem..............

1. Remove the counter assembly unit from the 820.

2. Remove both circuit boards from the counter assembly ( upper and lower boards

).

3. Scrape away the varnish from the corners of the boards where the

interconnecting screwes and spacers hold the boards into the case.

4. Reassemble the counter....

That should take care of the problem..
New Display Tube for DG-1

The original display tube (LD-8109) used in the DG-1 digital display for the TS-820
and TS-820S has been discontinued by the manufacturer. However, there is a
replacement tube available. This tube is the LD-8135. It is not a direct replacement for
the original tube. The leads come out of both ends of the display tube instead of just one
as in the LD-8109. Therefore, it will be necessary to replace the complete display unit if
the display tube fails. The part number of the new display unit is X54-1310-00.
Please use this part number when ordering a replacement display unit. The new display
unit is being installed in the current production of the TS-820S and DG-1.

The new display unit (X54-1310-00) is a little more involved to install than the old one.
The installation is as follows:

1. Remove the top cover of the TS-820 (or TS-820S) and set the unit on the bench

so the front panel is facing you.

2. Remove the two screws from the original display unit (save them), unplug the

display unit forom the counter assembly and remove the display unit from the
transceiver.

3. Run the connector of the new display unit through the left bracket (from the

center).

4. Gently (but firmly) push the right side of the display unit throught the right

bracket. ( This is the most difficult part).

5. Gently push the left side of the display through the left bracket.

6. Install the screws from the old display in the mounting bracket of the new

display unit and plug the connector into the counter assembly.

7. Turn on the TS-820 (or TS-820S) and make sure the display tube works

properly.

8. Replace the top cover of the transceiver.

TS-520, TS-820 CW filter select control

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In the TS-520SE, the heater switch has been replaced with a CW WIDE/NARROW
select switch. For those operators who desire this type feture for their transceiver, the
following information may be considered as a guideline.

TS-520S series transceivers

1. A minature SPDT switch may be installed at the operators preference, on the

rear side, or bottom panel. Use this to switch the CW or SSB filters by wiring
the BROWN lead, which normally is transferred to the CW terminal on the IF
unit, between the SSB filter, for WIDE , and CW for NARROW>

2. A Traditional solution has been to use the FIX CH switch, position 3 and 4 for

filter switching. This may be donw by completely rewireing the switch, or by
leaving the switch wiring and the filter wiring as for normal operation, and
bridging the following terminals:

3. A. FIX CH C terminal to IF SSB Terminal

4. B. FIX CH 4 terminal to IF CW terminal

5. Placing the FIX CH switch to 4 will operate the SSB

filter

6. in CW mode.

TS-820S Series Transceivers

1. Similar to the TS-520 series, a miniature SPDT toggle switch may be installed at

the operators preference a the rear or on the obttom cover.

2. The FIX CH switch, or Digital Hold switch may be rewired to control the CW

wide/narrow function

On the MODE switch, S6-1, the SSB filter control is GREEN, and the CW filter control
line is GREY. Break the GREY line and connect it from the MODE switch to the SPDT
common terminal. Connect the GREY line to the IF unit ot one terminal, and bridge tht
GREEN SSB line to the other Switch terminal.
Installing AUX Band in TS-820 (RX only)

Author: Trio-Kenwood Communication, inc.

Service bulletin no. 11 13-1-1977

The following information is for the installation and alignment of the AUX band inthe
TS-820. This extra band will be for receive only. Reference will be made to schematics
and board layouts as shown in the Service Manual.

INSTALLATION

1. Remove the top and bottom covers.

2. Remove the Connectors from the PLL Assembly.

3. Remove the PLL assembly and set it aside.

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4. Use the board layout of the Coil Pack to locate thepositions for the ANT and

MIX coils on the Coil Pack.

5. Install the ANT and MIX coils on the Coil Pack.

6. Remove both covers from the PLL Assembly.

7. Remove the 5 Phillips head screws holding the PD Unit in the PLL assembly

and carefully remove the PD unit.

8. Use the board layout of the PD unit to locate Q11.

9. Install R01, R02, C01, C02 and X01 as needed for the band desired.

10. Locate terminals AUX, B1, B2, B3, and B4 on the PD unit.

11. Install a jumper from the AUX terminal to the B terminal for the band desired.

B1 is for 1.8 MHz to 9 MHz, B2 is for 10MHz to 18MHz, B3 is for 19MHz to
24MHz and B4 is for 25MHz to 30MHz.

12. Replace the PD unit in the PLL Assembly.

13. Use a 3mm nutdriver to remove the 4 hex nuts mounting the VCO unit in the

PLL assembly, then remove the two phillips screws.

14. Carefully remove the VCO unit from the PLL assembly.

15. Use the board layout of the VCO unit to locate Q11.

16. Install C01, C02, C03, C04, C05, and T11 as needed for the band desired. Install

T11 last.

17. Replace the VCO unit in the PLL assembly.

18. Install the connectors on the PLL assembly.

ALIGNMENT

1. Turn on the TS-820.

2. Tune VFO to 250.

3. Set band switch to AUX.

4. Set the TUN/NOR switch on the VCO unit to TUN.

5. Connect a frequency counter to terminals TP5 and TP6 on the VCO unit. (TP6 is

ground).

6. Adjust T11 for a frequency of 9.08 MHz plus the lower limit of the band

desired.

7. Connect a frequency counter to TP4 and ground on the PD unit, and verify the

frequency of the reference oscillator. It may vary +/- 500KHz.

8. Return the TUN/NOR switch on the VCO Unit to the NOR position.

9. Turn off the TS-820S.

10. Replace the covers on the PLL assembly and reinstall it in the transceiver.

11. Replace the top and bottom covers on the TS-820S.

CAUTION
Do no use magnetized tools when working on the PLL assembly. Beryllium tools would
be better than ferrous ones. If the PLL assembly should become magenetized, use a bulk
tape eraser on open core AC transformer to demagnetize it.
TA7201P Substitution Parts Kit

The Toshiba TA7201P audio amplifier (Q3) used in the TS-820(S) and R-820 is no
longer available. The part has been replaced with a kit (Part # W05-0257-00). This

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