Modifications for the Kenwood TS-50

TS50 FIX: LCD display dark

No display illumination, LEDs On Air, AT TUNE no function The menu item 2 has no effect, display keeps always dark.
All other functions normal.

Possible reason:
Bad contact LCD Assy for 5V line to R9, R10 and IC5.
Power on the TS50 and check voltage at R9/R10.
If voltage is 0V, but display readout is active, the reason might be as discribed.

Measurement to fix it:
Look for the small hole near R9 at the LCD Assy, component side view, where the contact between the two sides of the LCD Assy is located.
If you have no service manual:
This is the side oriented to the front side of the device.
R9/R10 are located close to the two LEDs.
Take a small size needle to pick through the contact hole to encrease the diameter.
Make a contact between the two layers by soldering a piece of wire across the hole.
Check the 5V at R9/R10.
73, Mario

TS50<-->AT50 communication

 |      TS-50 <--> AT-50      Communication        |
 |        as measured/discovered by DF6KR          |
 |        No guarantee for whatsoever....          |

Communication method:   Serial interface
Tranfer rate:           4800 bps
Synchronization:        Start-stop (Asynchronous)
Parity:                 None
Signal format:          TTL level (!)

        |       +---+       |   1:  Ground
        |   1   | 2 |   3   |   2:  TT (TS50<--AT50)TTL!

 ACC    | +---+ +---+ +---+ |   3:  TS (TS50-->AT50)TTL!
        | | 4 |   5   | 6 | |   4:  N.C.
        | +---+       +---+ |   5:  ATG (signal ground)
        +-------------------+   6:  +13.8V from TS50
      Rear Panel Connector ACC


1. at Power-on:

    +------------------+ ++1         ++3++6
TT--+                  +---------------------->
    |                  |  |           | |
    |       1.45 sec---+  |           | |
    +--+                  ++2         +-+4,5
TS--+  +--------------------------------------->
       |                   |<- 600ms->|
    0  + 90ms               resume time       t

       1         3              6
TT: ;;;;;0C;___0D01;__________0F11;
             2        4    5
TS: ________0C;_____0D01;0F11;____

1: Power on comm.
2: Power on answer
3: Auto on request
4: Auto resume finished
5: ok at50
6: ok answer ts50

2. DOWN-UP-Communication

TT: 0E02;__________0F11;__   - UP from 1.8 to 3.5
TS: _____0E02;0F11;_______

0E04;0E04;0F11;0F11;   UP 3.5 --> 7
0E05;0E05;0F11;0F11;   UP 7   --> 10
0E06;0E06;0F11;0F11;   UP 10  --> 14
0E07;0E07;0F11;0F11;   UP 14  --> 18
0E08;0E08;0F11;0F11;   UP 18  --> 21
0E09;0E09;0F11;0F11;   UP 21  --> 24.5
0E0B;0E0B;0F11;0F11;   UP 24.5--> 28
0E0C;0E0C;0F11;0F11;   UP 28  --> 29
0E01;0E01;0F11;0F11;   UP 29  --> 1.8


TUNE:             0D03;0D03;0F41;0F41;
AUTO OFF (THRU):  0D00;0D00;
AUTO ON:          0D01;0D01;
tune error:       0d03;0d03;0F83;0F83;

TS-50 Power Mod for QRP

"Honey - I Shrunk the Rig"
by Bob Gobrick WA6ERB

No this is not an article about Kenwood shrinking their new TS-50 HF rig into a "CB" sized package, but the "shrinking" of the low power level on the TS-50 from 10 watts to 5 watts output in order to "officially" comply with the nationally recognized QRP power level for contest operation.

Prepare yourself before you remove any covers from the TS-50 - this is no Hallicrafters (feel a little dated) with 6L6's glowing in the inside. All components are surface mounted and to conserve space surface mounted subassemblies stand up at right angles all over the place. No place to work with that stubby tipped Weller soldering gun. But have no fear, this QRP mod is simple - you just need a screwdriver with a blade the size of a toothpick.

If you check the schematics you will see on the TX/RX board two potentiometers to set the Low 10 watt (pot VR15) and Medium 50 watt (pot VR16) power levels. The high power level is fixed at 100 watts by resistor R214. Our goal is to get to VR15 and set it for a 5 watt output.

First remove the top cover, set aside speaker and remove the latched speaker bracket (gives you better operating room). Locate two teeny-weeny pots next to IF filter module in the middle of the TX/RX board. The pot closest to the front panel is VR15 (low power adjust) and the one closest to the back of the rig is VR16 (medium power adjust) - the pots are somewhat marked on the PC board. Hook up a QRP wattmeter, dummy load and power and while in th low power mode adjust the pot (I used a flat blade calibration tool I had around) for 5 watts. That's it. You may notice that you can crank the pot all the way down to 0 watts so set where you want. I suspect the medium power adjustment with VR16 can also go to zero so maybe you can go QRPp by setting the low power pot for 999 mw and the medium power pot for 5 watt.

PS: Kenwood Service cautioned that their automatic antenna tuner requires 10 watts to actuate so this adjustment may affect that operation. You may want to check if Kenwood actuates the low power mode when the antenna Tune button is pressed. Also don't expect to run this rig off of a small solar cell for field day - the unit and all of it's surface mounted components draws a bit of power - enough for the internal fan to come on even in the QRP low power mode.

TX Coverage mod TS-50
OLD version

Hi folks,

I just got a spanking new Kenwood TS-50S

Searching around the local LLBBS's I found a very simple mod for full transmit from 1.7 - 30 mhz....

Remove the bottom cover of the TS-50

Locate the PLL board --
it is the pc board on top of the main board,
it has a shield on it's right side.

Locate the only non-surface mounted component on the PLL board --
look near the rear left-hand side of the pll board (front of radio facing you) and remove the very obvious diode. You can't miss, ther's only one.

Replace cover.

Perform microprocessor reset as described in your manual.

Credit for this photo is attributed to Hugh Brunson - AE4N Notice the callsign on the speaker. TNX,
Hugh Brunson - AE4N

TX Coverage mod TS-50
NEW version

I purchased a new TS-50S in May 2001, to enable Wideband TX cut D3 & D4 on the digital unit X46 - 315X - XX.

I purchased another new TS-50S today 10/10/2001 the mod is the same except cut D5 as well to enable.

Enable this mod entirely at your own risk and responsibility.

TX Coverage mod TS-50
Australian version

Tx mod for TS-50S originally from Sydney, Australia in 1995.

Review the mod in where the coloured picture of the control board is provided. This shows a picture of D5. The pads for D1 through D5 are obvious on the control board which is piggy backed on the PLL board with 2 multipin sockets and 2 screws.
This radio only had D4 obvious - snipping it did not do the job. D1, D2 and D3 were not fitted. (D5 not fitted next to D4 - see below)

Disconnect the power.
Ground the radio and keep one hand on the metal work or use a wrist strap to ground yourself. Locate the Control Board as it says in the Instruction Manual for "Options Installation" and "TCXO UNIT (SO-2)".

Remove the control board as it says in the book.
The 3 plugs are not as such plugs - the catch bar releases the ribbon cable and is easy to push apart but a bit fiddly to get back in. 3 hands might be needed and you have to push the bar down as well as in.
Very little force is needed. Do not force it - if it wont go in then you have not got the right angle.

The 2 screws required the use of a special tool which was not available. A fine pointed set of side cutter wire snips can be used to tightly grip the round headed screws by the dimples.

Suggest you locate the 2 white plug/sockets visually by looking under the Control Board before you pull off the Control board from the PLL board so that you dont bend the pins since it has to go strait up at both ends.

Under the board (under D5) was found what looked like a blob of opaque glue about 4mm diameter. Under this glue could be seen a black speck. The glue was levered off and a Surface Mount diode came off with it - breaking away from the PCB track. Diode about 1.5*1mm.
Obviously this blob was doing the function of D5 which was pictured in

A full "Microprocessor Reset" as it says in the Instruction Book gave the desired result.

Important note to 0-30 MHz TRX mods

If you want to make your TS50 tranceiving 0-30 and find more then 1 diode in your radio, PLZ watch out! Dnt remove diode nr1! Remove nr5.

If you remove diode nr1 your radio is history!
19-01-2000 New version. General TX for TS-50
From: - Jon

The new version of the TS 50 has three non surface mount diodes to be cut for general TX.

CAT control for TS-50S

I wish to offer an cheap solution for solid work with CAT control with your transceiver Kenwood TS-50S and PC. After long examinations and testing.
I found out following solutions as most acceptable:
  1. Interface IF-10D (227DM) and serial interface RS-232C (283DM) with program.
  2. Interface IF-10D,line DIN6P connector and DB9 for PC (COM1), 2 germanium diodes, 2 condesators 10nF, which acts as RS-232C !
  3. Small home made interface, in SMD technology, on the PCB 2x3 cm,integrate with TS-50S on the lower side of its PCB. The connecting line with PC can be home made. This can be done by specialists which can achieve an cheap solution.
The most convenient solution is mentioned under 2. Software is selected between 40 different solutions.The best one that made by N3EQF, RIG-EQF ver. 1.02. He is well known author for LOG-EQF software. This software is produced for TS-940S ?, but it works OK with TS-50S. The program runs after command RIG-EQF 1, for COM1 and RIG-EQF 2, for COM2. I tested program on laptop T2200SX25 and on PC 80386DX40.
The program is easy to use, with simple commands. The program can be activated only if all his hardwware is on, interface, PC and TS-50S. When the program is active the working frquecy is displayed,very precisely registering each change, then RIT control, modulation, VFO A and B, SPLIT etc.
Option O has possibility to input 22 different QRGs, modulations, descriptions and call sigs. Then you can choose any of them with coursor.
With key P is possible to obtain scanning of frequency in the wished range,then step raster and speed.
The second program , witch works the same things, but in litlle bit reduced range, is KEN-AE6G, dated 1990. it has VFO A and B control, and M memmory control. It is intended for use with TS-440 and TS-940s!
I include the plan of connection for IF-10D to DB9 pin PC port. The software can be downloaded from BBS and programs are very well sorted on FBBS of IV3LAV-8 via IR3GO (gonode). Using yapp protocol all can be quickly dowwnloaded from subfolder RTX. Names are RIG-EQF.ZIP 71.005 bytes, and TS50.ZIP - 6.847 byta. Detail description, schemas and know-how will be published in "Radio HRS",edition of 9A union.
On my TS-50S I tried the work with 2 computers: laptop worked with CAT-control, while PC 386 worked with SSTV (Hi )! The work was stable.

I wish to all CAT enthusiasts a lot of pleasure.

Vy 73 de !
Connection "home made" cable to IF-10D to PC:
  IF-10D                                                    PC-DB9
_________                                                _____________
  1. o GND------------------------------------------------o 5.(GND)
  2. o TXD------------------------------------------------o 2.(RXD)
  3. o RXD---------------------------I>I------------------o 3.(TXD)
                                  |--I I--|
  4. o CTS-----------------------------------I>I----------o 7.(RTS)
                                          |---I I---|
  5. o RTS------------------------------------------------o 8.(CTS)
  6. N.C.
        -I>I- germanium dioda -in ser!
        --I I---paralel diods kond 10nF
 de Iko-73!

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