Look for a bad solder connection. I have seen many on these build it yourself
amps. Mike
-----Original Message-----
From: Steve London <n2icarrl@gmail.com>
To: amps <amps@contesting.com>
Sent: Sun, Jan 20, 2019 4:06 pm
Subject: [Amps] SB-220 tick,tick,tick
I have an SB-220, of unknown lineage.
While using it, I noticed that on receive, listening on my receiver, I was
hearing a strong tick, tick, tick sound, about 3 ticks per second. With a
little
experimentation, I noticed the tick rate was higher in the SSB position than
the
CW position. At audio frequencies, I localized the source to the HV area of the
amp. My guess would be filter capacitors, rectifiers or equalizing resistors. A
few more data points - the equalizing resistors are not the original - they are
100K, rather than the original 30K. The electrolytics are Nichicon 200uF, 450
WV, 85 degree C. That's probably not original, either. I don't see any cracked
resistors. Best course of action ? Replace the electrolytics ?
73,
Steve, N2IC
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