I'm checking the frequency at the output connector. I could also check it at Q94 but I think that either way, I can't quite squeeze 10.000MHz out of the oscillator.
Thanks,
Barry - N4BUQ
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----- Original Message -----
From: "David C. Partridge" <david.partridge@...>
To: "tekscopes" <[email protected]>
Sent: Tuesday, December 7, 2021 11:58:36 AM
Subject: Re: [TekScopes] 10Mhz under frequency in 184 Time-Mark Generator
Don't measure the frequency at the xtal - you will pull it down a load.
Measure at the output of the 1st gain stage (collector of Q94).
David
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of n4buq
Sent: 07 December 2021 16:30
To: tekscopes <[email protected]>
Subject: Re: [TekScopes] 10Mhz under frequency in 184 Time-Mark Generator
At cold start, with 0.1us selected, the output checked 9.9981MHz. After about a
90 minute warmup, the crystal can is warm to the touch, cycle time is much
longer, and the output still checks 9.9981MHz. I was going on memory that the
output frequency was 9.999x and that's incorrect.
I'll have to check the components as well as the interaction of L9. I think I
adjusted that for uniformity of the markers but I don't think I tried checking
to see whether I can reach a compromise between L9 and C8 to get good results
for both frequency and marker uniformity.
Thanks,
Barry - N4BUQ
