[time-nuts] Finally acquired a 5370B

Didier Juges didier at cox.net
Wed Jun 11 22:20:00 EDT 2008


> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Bruce Griffiths
> Sent: Wednesday, June 11, 2008 9:03 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Finally acquired a 5370B
> It is usually worthwhile to check the frequency multiplier 
> chain alignment and the waveform at the 10MHz output.
> Careful alignment of the frequency multiplier chain can 
> reduce the noise significantly.
> Sometimes the solder joints at the silver mica capacitors can 
> have high resistance.
> Alterations such as disabling the A8U1 10MHz present detector 
> have also been found to significantly reduce noise.
> Since this detector just drives an LED no functionality is lost.
> Bruce

Yes, I forgot I had that problem too. The external 10 MHz input circuit had
a cold solder joint in the tuning capacitor for the output tank, which was
resonating around 30 MHz instead of 10. The counter was not very happy with
it. Based on Bruce's suggestion, I reflowed the solder joints on the 3 or 4
silver mica caps and all was good.

Didier KO4BB

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