RadioBanter - View Single Post - Kenwood TS-450s

Fred McKenzie · February 14th 17, 06:06 PM posted to rec.radio.amateur.equipment

In article ,
wrote:

On Saturday, 25 May 2013 19:25:54 UTC-3, Yorklynyankee wrote:
Thank all of you for your suggestions. Just for the record, I don't
operate CB radio, I am a retired Research & Development electrical
engineer from HP, and I have a masters degree in Electrical
Engineering.... now to answer some of the questions. As I mentioned in
my first posting the radio is connected to a 50 dummy load. By low
output power I mean 5~10 watts, I have tried two different microphones.
I have another Kenwood TS-450 so I have a working radio to compare their
outputs. When I whistle into the radio using USB/LSB on any bands at any
frequency, the radio will only put out 5~10 watts. Whereas under
identical conditions the working radio will put out 100 watts. There is
absolutely NO DOUBT that this radio's USB/LSB is not working. The same
radio puts out 100+ watts on CW and FSK. I suspect something in the
balanced modulator, but I am looking for someone who has encountered a
problem like this before. This radio is known for having some common
problems, like C104, so I was hoping that there was another frequently
failed component that causes this problem.

--
Yorklynyankee

Having same problem with my 450. Did you find the problem? Colin...

Colin-

I have the TS-690, which is a TS-450 with Six Meters. So far, the only
obvious problem I have had was due to a leaking electrolytic capacitor
in the audio output circuit. It seems the leaked electrolyte ate
through one of the foil circuits in series with audio output. I was
able to repair it by replacing the capacitor and adding a jumper across
the foil.

I also have had problems with an old Kenwood TS-50. Several
electrolytic capacitors have gone bad, sometimes leaking. It can be
very frustrating fixing one problem and then finding more that were
hidden by the first. I conclude that Kenwood has had problems with
electrolytic capacitors.

Good luck.

Fred
K4DII