On Mon, 12 Aug 2002, Morgan Olsson wrote:

>Hej veronica.merryfield@tesco.net. Tack f=F6r ditt meddelande 11:59 2002=
-08-12 enligt nedan:
>>I would make a small LC tank centered at 12Mhz across a scope input wit=
h an
>>arial close to the xtal
>
>I suggest a current pickup held to supply trace would pick up stronger s=
ignal, plus not interfere at all with xtal resonance.
>
>Problem is finding a good 12 000 000 Hz reference.
>good Xtal and caps & osc, helt at controlled constant temperature
>...but what to calibrate to?

Frequency standard, 10e6. 12e6 =3D 10e6 + 10e6/5. Or calibrate a counter =
to
10e6 then use it to measure 12e6. He probably does not need 1 part in
12e6. That's about 0.3 sec/month in a timer. That kind of timer would use
a TCXO at the very least. It is equivalent to 0.08 ppm. My heterodyne
method described in another message allows easy tuning to +/-2Hz at high
productivity. 2Hz at 12e6 is 1/6e6 or 0.16 ppm or 0.6 sec/month (much les=
s
than 1 sec/month in any case).

Peter

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