[time-nuts] Looking for insight with an hp 5350B 20GHz counter

[walter shawlee 2]

I recently got a nice looking 5350B counter, but bench tests showed a strange 
problem.  the low frequency section is fine, but the high frequency section only 
runs to 14Ghz, and is about 20dB less sensitive than it should be (-10dBm v. 
-32dBm).  the manual shows that there is nothing between the input and a 
mysterious undocumented circle labeled U1 Sampler.

There are no real diagnostics for this portion other than a live signal, and it 
appears to a non-user service item. Overloading the input is a tragically common 
way to damage the front end, so I am a bit worried that is the problem here. Is 
there anyone with some similar experience with this counter that can give me a 
bit of good troubleshooting advice?  there is a very good and detailed set of 
diagnostics for this unit, except this one input portion, but it would be 
helpful to know if this is symptomatic of a damaged input sampler before I burn 
up many bench hours testing everything else.

all advice welcome,
regards,
walter

-- 
Walter Shawlee 2, President
Sphere Research Corporation
3394 Sunnyside Rd.,  West Kelowna,  BC
V1Z 2V4  CANADA  Phone: (250) 769-1834
walter2 at sphere.bc.ca
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