Modifications for the Kenwood
TS-50

19-07-1998 TS50 FIX: LCD display
dark
From: DJ7UA @ DB0QS.#NRW.DEU.EU
(Mario)
Problem:
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
DJ7UA

19-07-1998 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
Timing:
1. at Power-on:
===============
+------------------+ ++1 ++3++6
TT--+ +---------------------->
| | | | |
| 1.45 sec---+ | | |
+--+ ++2 +-+4,5
TS--+ +--------------------------------------->
| |<- 600ms->|
0 + 90ms resume time t
Signal:
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;_______
same:
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
DOWNs
0E0C;0E0C;0F11;0F11;
0E0B;0E0B;0F11;0F11;
.
.
0E01;0E01;0F11;0F11;
TUNE: 0D03;0D03;0F41;0F41;
AUTO OFF (THRU): 0D00;0D00;
AUTO ON: 0D01;0D01;
tune error: 0d03;0d03;0F83;0F83;

19-07-1998 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.

19-07-1998 TX Coverage mod
TS-50
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.

23-01-1999 CAT control for
TS-50S
From: [email protected]
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:
- Interface IF-10D (227DM) and serial interface RS-232C (283DM) with
program.
- Interface IF-10D,line DIN6P connector and DB9 for PC (COM1), 2 germanium
diodes, 2 condesators 10nF, which acts as RS-232C !
- 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 [email protected] !
Connection "home made" cable to IF-10D to PC: IF-10D PC-DB9
_________ _____________
DIN6P.
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!

14-02-1999 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
The new version of the TS 50 has three non surface mount
diodes to be cut for general TX.

22-04-2000 TS-50S Lithium battery
replacement notes
Author:
Kenwood Communication, inc.
Service Bulletin no. 1015 (10 May 1993)
Procedure:
Immediately after replacing the Lithium battery you must
cycle the radio ON then OFF. Failure to follow this procedure will result in
premature failure of the battery. If the power is not cycled ON then OFF the
microprocessor will immediately begin drawing approximately 1 mA of power from
the Lithium battery, resulting in poor battery life.
When the battery is replaced we recommend the insulation sheet also be
changed. Part numbers for the battery and insulation sheet follow.
Parts required:
Qty Description Kenwood Part No. Circuit description
1 Lithium battery W09-0515-05 BA1
1 Insulating sheet F20-0521-04 --
Caution: This modification requires soldering equipment rated
for CMOS type circuits. It also requires familiarity with surface mount
soldering techniques. If you do not have the proper equipment or
knowledge do not attempt this modification yourself. Seek qualified
assistance.
Time required for this modification is 15 minutes or less.

23-04-2000 TS-50S "Hello" displayed during
TX
Author: Kenwood
Communication, inc.
Service Bulletin no. 1030 (29 June 1993)
Symptom:
Occasionally an "Hello" message will appear in the display
of the transceiver when the TS-50S is loaded into a antenna without the use of
an antenna tuner. This symptom usually occurs when the negative terminal of the
power supply is floating (un-grounded for RF). This can result in RF feedback
that causes the supply voltage to exceed to 16 Vdc.
Corrective action:
- Cut the Final Unit PC Board foil in two places, as shown below.
- Add a .01 µF chip capacitor (C125) as shown below.
- Add a 10 µH chip Ferri-inductor (L102) as shown below.
- Add an insulated jumper wire as shown below.
Parts required:
Qty Description Kenwood Part No. Circuit description
1 .1 µF chip capacitor CK73EB1E104K C125
1 10 µH Ferri-inductor L40-1001-48 L102
Caution: This modification requires soldering equipment rated for
CMOS type circuits. It also requires familiarity with surface mount soldering
techniques. If you do not have the proper equipment or knowledge do not
attempt this modification yourself. Seek qualified assistance.
Time required for this modification is 30 minutes or less.

23-04-2000 TS-50S Antenna lead
wire
Author: Kenwood
Communication, inc.
Service Bulletin no. 1035 (7 December 1993)
Symptom:
Several users have reported a problem with the antenna
lead connection, i.e. the lead that connects the antenna connector to the Filter
unit (X53-3120-xx). Originally this connection was made by a zero ohm resistor.
If excessive stress is placed on the antenna connector this lead is easily
broken, with a resulting loss of receiver sensitivity and transmitter power. The
use of a small flexible jumper wire will increase the flexibility of this
connection, thus minimizing the effect of mechanical stress.
Parts required:
Qty Description New part No. Circuit description
1 Cable E37-0445-05 W2
Procedure:
Remove the zero ohm resistor and replace it with the
small piece of cable. See accompanying diagram.
Caution: This modification requires soldering equipment rated for
CMOS type circuits. It also requires familiarity with surface mount soldering
techniques. If you do not have the proper equipment or knowledge do not attempt
this modification yourself. Seek qualified assistance from your closest Kenwood
Service Center (Long Beach, CA, or Virginia Beach, VA).
Time required for this modification is 30 minutes or less.

23-04-2000 TS-50S Mechanical noise from
final unit
Author: Kenwood
Communication, inc.
Service Bulletin no. 1044 (28 March 1994)
Symptom:
When the transceiver is subjected to vibration a
mechanical noise can be heard from the output transformer area. This has led to
concern by several consumers that something is loose or improperly installed.
Corrective Action:
In order to ease consumer concern toy should add
a cushion under transformer L4 as shown in the accompanying diagram, and replace
transformer L13 at the same time. This transformer has been fastened to the
circuit board with high temperature adhesive, so use caution when removing it
from the circuit board.
Parts required:
Qty Description Old part No. New Part No Circuit Description
1 Cushion NA G13-0871-04 (Under L4)
1 Output transformer L39-1209-25 L39-1252-05 L13
Time required for this modification is 30 minutes or less.
