1 Mhz Standard source
Jan 20th 2012, 12:34 | |
kf4tvyJoined: Nov 22nd 2011, 06:31Total 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 | |
W1VTSuper Moderator Joined: Apr 4th 1998, 00:00Total 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 | |
kf4tvyJoined: Nov 22nd 2011, 06:31Total 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... |