[Elecraft] XG50 - Frequency Instability - Resolved

[Phil Wheeler]

Thanks for posting that, Gary. As a user of the 
XG50 it's reassuring that you have resolved this 
issue.

Phil w7ox

On 5/22/14, 9:53 PM, kj7rt at kj7rt.com wrote:
> First I want to thank those that pointed out that my first two postings
> didn't contain message content, probably due to using HTML. You were
> right, I changed the default for this email program to plain text.
>
> Second thank you to the responders that suggested solutions to my
> "instability" non-problem. Turns out it was the input level to the HP
> 5334A. Adjustment of the counter nailed it pretty close. Stabilized at
> 49.380000 MHz +-2 Hz.
>
> 73
> Gary Marklund
> KJ7RT
> Sun City, AZ
> USA
>
>> -------- Original Message --------
>> Subject: [Elecraft] XG50 - Frequency Instability
>> From: <kj7rt at kj7rt.com>
>> Date: Thu, May 22, 2014 7:31 am
>> To: Elecraft at mailman.qth.net
>>
>>
>> I am trying to use my XG50 to run the Extended Temperature Compensation
>> Procedure on my KX3. This is the first time I have attempted to use the
>> XG50 since building it. I have completed the 8 hour burn-in.
>>
>> When I first connect the XG-50 to my HP frequency counter, I get a
>> reading of something like 49.379990. Then after running for several
>> minutes it starts dropping in frequency to something more like
>> 49.32xxxx. It is still wildly fluctuating. If I connect the 10MHz output
>> of my Trimble Thunderbolt GPSDO to the counter it stays quite stable
>> just below 10 MHz.
>>
>> I re-soldered all the XG50 components and tried with both a metered
>> home-brew power supply and a 12v SLA battery with the same result
>> although re-soldering made a significant but not permanent improvement.
>>
>> My lab is in my photographic darkroom which has an ambient temperature
>> of about 68 degrees F and the AC does blow across the work area.
>>
>>
>> Thanks,
>>
>> Gary Marklund
>> KJ7RT
>> Sun City, AZ
>> USA