[Collins] 75S3B drift parameters

[Dr. Gerald N. Johnson]

Warm up time is probably 15 minutes to an hour. One time I tried 
monitoring 20 meter packet all day. While the forwarding stations held 
their frequency to 10 Hz, my 75S-3B wandered randomly about that 100 Hz 
over the day and required retuning at probably hourly intervals to keep 
copying packets. This is a 75S-3B that I bought as an employee and its 
PTO had zero end point spread when new and in the 70s with very careful 
use of the calibrator and a well practiced slide rule interpolating 
eyeball, I did better than 1ppm on 7 MHz in an ARRL Frequency Measuring 
Test. That's an error less than 7 Hz. But I didn't give it time to drift 
after setting the calibrator on WWV and then setting the dial with the 
calibrator.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association

On 9/28/2011 12:47 PM, James Liles wrote:
> The Collins published drift parameters for the 75S-3B state that you can expect up to 100 cycles after warm-up.  Can anyone articulate in a more specific way what that might mean?  What is after warm-up?
>
> Thanks and Kindest regards Jim K9AXN
>