[time-nuts] How I got my FE-5680A to lock in Sydney, Australia

Charles Steinmetz csteinmetz at yandex.com
Sun Feb 9 23:37:29 EST 2014


Jim wrote:

>Here's what I found, as before looking at the frequency with my 
>counter (GPSDXO 1pps timebase):
>
>Inverted position:  swings between 9,999,798Hz and 10,000,001Hz, 
>before locking.
>Normal position:   swings between 9,999,756Hz and 10,000,057Hz, a few times.

Are you sure you didn't transpose the "high" swing numbers?  As you 
state it above, the oscillator swings 203 Hz (peak-to-peak) when 
inverted and 301 Hz p-p right-side-up.  If we swap the "high" swing 
numbers, it is 245 Hz inverted and 259 Hz right-side-up, which seems 
more plausible.  There seems to be little reason why the absolute 
value of the sweep range would vary so much (203 to 301).  Also, a 
normal range of 9,999,756 to 10,000,001 and an inverted range of 
9,999,798 to 10,000,057 would seem to explain your previous results, 
while the results reported above would not.

I'm a little confused by what you've said about your counter time 
base -- as I recall, you said you were feeding GPS 1pps to the 
counter.  I'm not familiar with any counter that locks to 1pps -- 
most counters I'm familiar with lock to 10MHz (or in older gear, 5MHz 
or 1MHz).  Can you say a bit more about your "1pps timebase"?

Best regards,

Charles






More information about the time-nuts mailing list