[time-nuts] PRS10 C900 replacement

davidh dhooke at gmail.com
Fri Feb 26 06:52:51 EST 2016

Hi All,

I used the TAP225K035SRW, from Mouser, and have the PRS10 running again. 
In the process of pulling it apart I managed to break one of the glass 
thermistors (Mouser replacement from US Sensor, part number 104JG1F). Doh.

Whether it was the lamp temperature change (thermistor) or mechanical 
alignment now being a bit different, the frequency moved by about 
300E-12 (measured by locking to my GPSDO 1PPS and comparing old to new 
"SF" values).

I've also added a cooling fan so the base plate is now below 40dC. I 
guess that could also affect the frequency.



On 20/01/2016 4:59 PM, Charles Steinmetz wrote:
> david wrote:
>> It's a 2.2uF cap, with a 0.125" lead spacing, and I'm looking for
>> 125dC temp rating. I wondered if there were other characteristics such
>> as ESR/ESL I need to keep in mind.
> You're on the right track.  Get the highest temperature rating available
> (which is probably 125C), buy only caps manufactured by one of the
> known-good manufacturers, and select from a parts series the
> manufacturer designates as "high reliability" (or equivalent).
> If it is a solid tantalum, I like the Vishay 199D Series.  The AVX TAP
> Series and the Kemet "T" Series ("UltraDip II") are also high quality.
> (This list isn't exhaustive -- these are just the ones I've had occasion
> to qualify.)
> Best regards,
> Charles

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