Re: ProgRock + TCXO + GPS Stability/Accuracy


Giuseppe Marullo
 

Hi Sid,

I know that some people got their "quirks" with the accuracy of this, you were not the only one looking back the ML.
I have received a new MCU, to rule out eeprom wear, since I kept it powered several weeks and if fhe eeprom is written once a second, well I expect it not to work anymore, theoretically it will die after 27hours. I was past 10x this period, easily.

My problem is not that it is not spot on on 10MHz. The problem is that it stays about 2.4Hz below 10MHz of my Trimble. It is almost constant, like either my Trimble is not 10MHz and it is stable, let's say it is @ 10.0000024MHz, or ProgRock decides that 9.9999976MHJz is the right frequency. I am evaluating getting another source for my lab, if I could acquire at a decent price. Unfortunately there is no visible feedback from the ProgRock about what is really doing, if it consider itself within range or what.

The most common "solution" recommended is to replace the xtal with a
TCXO which is no solution that simply masks the problem. That's the discipline...use a clock source that does not drift!!
Hehe, mind to give me a DigiKey part number with less than 12 digits in the price column? Everything drifts within a hobbyist budget, that the point in the disciplined part of their name.
I am already using QRPLabs TCXO BTW.

Waiting to perform the surgery on the ProgRock, then I will analyze the PSU too(didn't check it yet). Not much left to look at though.

I am building some GPIB interfaces to connect the frequency counter and log data programmatically, it will take 2-3weeks tough, waiting for AR488 pcb to arrive.

Giuseppe Marullo
IW2JWW - JN45RQ

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