kenwood TS-50 High-Power-Modification
As the most of you TS-50-Users surely know, it is possible to increase the Medium-Power, the Low-Power but not the High-Power-Setting. Reason: There is no Trim-Pot, it is a small SMD-Resistor. With that small Modification you'll get a Trim-Pot and the TS-50 is able to run up to 180 W output without any problems.
- Remove Top-Cover and hook out the internal speaker. Place the rig top up, display to you. The area you need is closed to the left side of the CW-Filter-Board on the main-RF-Board, where the Filter-Board is screwed on.
On the board is printed on 'PL', 'PM', 'PH' and an arrow. Above are two pots and two little black chips, the right one (SMD-Resistor) is very closed to the second pot.
- Remove this SMD-Resistor (R214, 10k), wich is located closed above the two pots for Med and Low. It is a VERY small black chip, marked with '103'. Be CAREFULL while soldering!!
- Make yourselfe a small Board, 25 mm long, 8-10 mm wide. At one end drill a centered 3mm-hole closed to the edge of the board.
- Solder one konventional 4k7-Resitor (standing, a 5k6 or 6k8 also can do it) and a konventional 10k-Trim-Pot (lying) in serial order on this board.
Make sure, you make no shorts and build the circuit as narrow as possible and very closed to the reverse end, from where you drilled the hole in - you later need 10mm space at the drilled end!
- Connect two two fine wires (length aprox. 20 mm) at the ends of this little circuit and solder it (CAREFULLY!!) to the free solder-joints of the resistor. To make it a bit easier: the right one you can solder to a joint about 4mm away of it - just follow the small trace to the right and you will find this lonesome contact.
- Remove the screw of the CW-Filter-Board, place your little board hole-on-hole on top of the Filter-Board and Re-Screw the two boards together to the main-board. So your little "Tuning-Unit" is fixed, hanging above the Med- and Low-pot.
- Connect the rig to a power-supply (25-30 Amps!), a power-meter, a dummy-load and switch it on. No smoke? So you might have done everything all right ;-)
- Push a FM-Carrier on 14Mhz and set the 'new' pot on the desired output. My TS-50 can do max 185 Watts but I have adjustet it to 150-160, so it modulates fine 130 Watts SSB with the original mike - what a difference to that 70 before... Don't adjust it to high, think about your finals and filters!
Note: You are making this Mod on your own risk, I am NOT responsible!