[time-nuts] E1938

Brooke Clarke brooke at pacific.net
Tue Oct 2 17:06:01 UTC 2007


Hi Rick:

If the aging drift is up in frequency then there might be an advantage in 
starting at the low end of the window.  Any idea of how these age?

Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Cam


Richard (Rick) Karlquist wrote:
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+brooke=pacific.net at febo.com RETRY
> 
> The labels may or may not be significant.  If the frequency
> is indeed -2.94 Hz at 2.5V EFC, you could probably get it back
> to 10 MHz by increasing the EFC voltage.  You can also decrease
> the bridge capacitor to bring the frequency up if necessary.
> The factory was supposed to choose the capacitor to get 10 MHz
> in the center of the EFC range.  If this is not correct, the
> oscillator is usually perfectly OK , and they just
> goofed on the capacitor.  The capacitor installation process
> had a lot of problems.  Should be safe to power it up and see
> what the status is.
> 
> Rick N6RK
> 
> Jeroen Bastemeijer wrote:
> 
>>); SAEximRunCond expanded to false
>>Errors-To: time-nuts-bounces+richard=karlquist.com at febo.com RETRY
>>
>>Dear All,
>>
>>After some shipping time, my E1938 arrived today! :-)  :-)  :-)
>>
>>Thank you Rick!
>>
>>First thing was examining the board, oscillator and the HP-test 
>>notes/labels. Most of the specs mentioned there are logical and numbers 
>>are very reasonable. ;-) However, one spec drew my attention: "Hz off 
>>freq. after warm up: -2,94". Does anyone know what it means? Is this the 
>>offset after warm-up without EFC applied?
>>
>>The unit hasn't been powered up. Whit the hardware at hand I first want 
>>to read some docs to be sure about what I'm doing. For comparison, what 
>>other numbers are around for the "Hz off freq. after warm up"-spec?
>>
>>Final result of the HP-test was: PASS. So, I assume this number is OK. 
>>What is your opinion? Looking forward to your reactions.
>>
>>73 Jeroen PE1RGE
>>
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 




More information about the Time-nuts_lists.febo.com mailing list