[Test-Equipment] HP 8673M 2-18GHz generator problem

Sat, 24 Jan 2004 20:30:56 -0800

John,

Thanks for your reply. I did fix the unit and it is amazing how simple
it was.

Someone mounted the minus 40volt power supply filter capacitor incorrectly 
on the power supply board. The -40volt power source was not being filtered at
all. Fixed that and the unit tool off and worked correctly, locking right up.
I then went through and adjusted all of the YIG preoutput freq settings according
to the manual, and the YIG driver for proper freq range. If anyone plans on doing
theirs, you will need to resolve to 6 digits of accuracy on those voltage settings.
Fortunately I have an HP 3456A 6 digit DMM to do this with. I checked the output
spectrum on my HP 8569B and looks like we are meeting specs for phase noise
and harmonics.

Jerry Mulchin - N7EME
JWM Engineering Group
http://jwmeng.com

At 07:00 AM 1/20/2004 -0800, John Miles wrote:
>How's the YTO's FM coil continuity?
>
>How's the output of the sampling-type detectector (phase gate) used to
>sample the YTO output?
>
>These things aren't usually too hard to troubleshoot if you have a manual;
>nearly impossible otherwise.
>
>-- jm
>
>> -----Original Message-----
>> From: [email protected]
>> [mailto:[email protected]]On Behalf Of Jerry Mulchin
>> Sent: Monday, January 19, 2004 11:16 PM
>> To: test-equipment
>> Subject: [Test-Equipment] HP 8673M 2-18GHz generator problem
>>
>>
>> To All,
>>
>> I just recently acquired a HP8673M, the military version of the
>> 8672  2-18GHz
>> Synthesized Generator. But it has a problem with the YTO loop not locking.
>> All of the other 3 loops are locking OK. But the YTO loop appears broken.
>>
>> Is there anyone on the reflector that knows of any common failure
>> mechanism
>> related the Yig Tuned Osc loop? The generator puts out power and
>> the initial
>> test done in the manual show that the pre-tune is working. So the
>> Yig Osc is
>> OK and tunes.
>>
>> Any help would be appreciated. Even the name of someone who repairs them.
>> I am willing to pay to have it fixed.
>>
>> 73
>> Jerry Mulchin
>> JWM Engineering Group
>> http://jwmeng.com
>>
>>
>>
>>
>>
>> Jerry Mulchin - N7EME
>> jwm Engineering Group
>> e-mail - [email protected]
>>
>>
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>
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Jerry Mulchin - N7EME
jwm Engineering Group
e-mail - [email protected]