I think I suggested this possibility since the limiter was capable
of shorting out the IF signal. Congratulations on finding the culprit.
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On 6/12/2024 5:18 PM, Floyd - K8AC wrote:
This started in another thread, which went off on a tangent and never
answered my question.? On my SX-117, switching the Noise Limiter on
resulted in the signals and background noise level just about
disappearing.? I wondered what should be heard when the NL is switched
on.? In my case, the problem was traced to one bad diode in the simple
noise limiter circuit.? The diode wasn't shorted or open, but exhibited
a resistance of 64 ohms in both directions.? That was enough to short
the IF signal to ground.? With the diodes replaced, when you switch the
NL on with no noise present, there is no difference in what you hear and
strong nearby signals do not cause any distortion.? The original diodes
are obsolete, but you can find them on eBay if you're willing to pay the
price.? Or, you can use 1N459A diodes as suggested by K9AXN.? They're
available from the usual suppliers.? At this time, there is no local
noise here so can't evaluate how well the NL circuit functions.
73, Floyd - K8AC
--
Richard Knoppow
Los Angeles
WB6KBL
SKCC 19998
