On 2/27/21 9:51 PM, Eliud Caraballo wrote:
I have this 8640b that got used, it shows voltage on the meter but does not have RF out. the frequency display works and tracks but the output does not trigger my 5328a counter.
Were should I start first to troubleshoot ? im perplexed that can see voltage with no output.
If I remember the 8640B's topology correctly, the detector that drives the level meter circuit is after the RF amplifier, but before the attenuator. The attenuator could have a problem (either fried by reverse power input, or contact problems), or the cable from the attenuator to the output bulkhead connector could have failed.
Do you have some way of measuring approximate RF power, like an RF power meter, or a coaxial crystal detector?
-Dave
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Dave McGuire, AK4HZ
New Kensington, PA
Dave McGuire