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1 Mhz Standard source

Jan 20th 2012, 12:34

plaiii

Joined: Nov 22nd 2011, 06:31
Total Topics: 0
Total Posts: 0
Hello,
Does anyone have a schematic for building a crystal controlled oscillator to be used as a 1 Mhz standard. I have a Heathkit IB-1102 Frequency Counter I want to calibrate. The manual says to connect a 1 Mhz standard to the back and then adjust. There are all kinds of oscillator schematics on the internet. I am hoping someone here will know of one better suited for my intended use. I have a new 1 Mhz crystal already. Thanks,

Leon...
Jan 20th 2012, 23:07

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0


Hi Leon,

Technology has come a long way since that counter was designed. These days, the most practical method of calibrating a frequency counter is to obtain a surplus TCXO (temperature compensated crystal oscillator) or OXCO (overn compensated crystal oscillator) and adjust the tuning voltage to precisely zero beat WWV on a receiver. The best of these oscillators feature SC cut crystals that are unusually stable.

http://www.mtechnologies.com/aade/tcxo.htm
This commercial product uses this approach.

Alternately, the ARRL Handbook features a Marker Generator with Selectable Output that uses some 7400 series TTL NAND gates wired up as an oscillator--you can use the output of U1C to drive your counter. Again, you will need to calibrate the oscillator before use.

Zack Lau W1VT
ARRL Senior Lab Engineer
Jan 22nd 2012, 03:49

plaiii

Joined: Nov 22nd 2011, 06:31
Total Topics: 0
Total Posts: 0
Thank you for the link. I had been searching for a source such as the TCXO2 but everything I found was very expensive. I just now ordered theirs.

Leon...

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