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Sorry Dave!!
Got confused before the third cup of coffee!!
On 28 Feb 2021 at 12:19, Dave McGuire wrote:

Eliud is the guy with the 8640B problem, not me.

I'm pretty familiar with them; I've had three and have used them
a
lot, and repaired them a few times.

Though, it has been years since I've powered one up...If memory
serves, the output level meter does not indicate power when the RF
output switch is set to off.

-Dave

On 2/28/21 8:43 AM, kim.herron@... wrote:

I don't know how familiar you are with the 8640B. Is the
RF output switch set to on?? In on the front panel right
above the main output on the generator. Look there first.
If you're not familiar with the gear, it's easily missed.



On 27 Feb 2021 at 22:00, Dave McGuire wrote:

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

--
Dave McGuire, AK4HZ
New Kensington, PA

Kim Herron W8ZV
kim.herron@...
1-616-677-3706

--
Dave McGuire, AK4HZ
New Kensington, PA

Kim Herron W8ZV
kim.herron@...
1-616-677-3706