Pages: [1]   Go Down

Author Topic: Help - Problem with my Kenwood TS-520  (Read 488 times)

KK5RH

  • Member
  • Posts: 8
Help - Problem with my Kenwood TS-520
« on: May 27, 2020, 06:59:19 AM »

Problem, will not tune in the tune mode. No bias voltage, no output in the tune mode.
However, in the cw mode it will tune up but not transmit unless the send switch is engaged.
I'm afraid to operate the radio like this in fear of damaging the finals.
Any suggestions on where and what to look for?
TIA - KK5RH
Logged

W0CKI

  • Member
  • Posts: 637
Re: Help - Problem with my Kenwood TS-520
« Reply #1 on: May 27, 2020, 07:25:41 AM »

Do you have a manual? You can adjust the bias to 60 mills with an adjustment in the back of the radio. It's normal to transmit when the send switch is engaged. There are several tune up instructions on line as well as manuals. Are you adjusting the drive and dipping the finals as suggested? Using CW or SSB?
Logged

THC1

  • Member
  • Posts: 10
Re: Help - Problem with my Kenwood TS-520
« Reply #2 on: May 27, 2020, 07:27:09 AM »

Check the soldering on the mode switch, try re flowing the connections.
Logged

KB7TT

  • Member
  • Posts: 264
Re: Help - Problem with my Kenwood TS-520
« Reply #3 on: May 27, 2020, 08:26:57 AM »

Try cleaning the mode switch thoiroughly and rotating at least 40-50 times.  A simple step but its a good place to start.  Kenwood mode switches of that age are known to become intermittent.  They pass low voltage signals and need to be clean. 
Logged

AB5CC

  • Posts: 51
    • HomeURL
Re: Help - Problem with my Kenwood TS-520
« Reply #4 on: March 05, 2022, 05:32:53 PM »

I had the same problem on a TS-530SE and found out that the TUNE mode doesn't put out power if there is a CW key plugged into the radio.  I unplugged the key and all is good.
Logged

W5RKL

  • Member
  • Posts: 1214
Re: Help - Problem with my Kenwood TS-520
« Reply #5 on: March 05, 2022, 08:20:43 PM »

Problem, will not tune in the tune mode. No bias voltage, no output in the tune mode.
However, in the cw mode it will tune up but not transmit unless the send switch is engaged.
I'm afraid to operate the radio like this in fear of damaging the finals.
Any suggestions on where and what to look for?
TIA - KK5RH

You say no bias voltage. How did you determine that?

Have you checked the rear panel "SG" switch?

SG switch must be in the ON position for normal operation, discussed in the operators manual.

You say CW mode only works when SEND switch is "engaged". Did you turn VOX ON
in CW mode? If not then you need to do that to use "Semi Break-in" which is discussed in
the 520 manual.

If VOX is turned ON but CW still doesn't work by pressing the CW key without SEND switch engaged then the
problem is a failed Q8 relay switch on the VOX Unit board.

73
Mike W5RKL
www.w5rkl.com


Logged
Pages: [1]   Go Up