[time-nuts] Basic question regarding comparing two frequencies

J. L. Trantham jltran at att.net
Sat Jul 24 22:40:41 UTC 2010


I would agree. GPIB (aka HPIB) is ubiquitous and is a great place to start.
Unfortunately, I haven't gotten that up to the top of my 'to-do' list yet.
I have a computer, HP and National interface cards, cables, but no time to
find the software to make everything communicate yet.  I think it has a lot
to do with the fact that I have relatively old HP equipment that is
relatively 'tongue-tied' but I think I will be able to figure it out once I
get the time.

Certainly the right place to start though, IMO.

Joe

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of J. Forster
Sent: Saturday, July 24, 2010 5:24 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Basic question regarding comparing two frequencies

"..  more generic interface." ??

The vast majority of professional test equipment has GPIB. Virtually
anything else is an "also ran".

FWIW,

-John

============


> Thanks, I'm glad to hear I am on the right track.   At some point it would
> be
> nice to obtain a counter that can measure the drift of the time base in
> the
> 5328A.  The 5328A has a GPIB interface but as the display only varies by a
> few
> counts I'm not inclined to track down a GPIB adapter just to plot this.)  
> Hopefully a newer counter would have a more generic interface.
>
> Best regards
> Mark Spencer
>
>
> ----- Original Message ----
> From: J. L. Trantham <jltran at att.net>
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Sent: Sat, July 24, 2010 1:49:51 PM
> Subject: Re: [time-nuts] Basic question regarding comparing two
> frequencies
>
> Sounds about right.  One cycle per 5 seconds or about 0.2 Hz difference.
> Therefore, 9,999,999.8 Hz.
>
> I would feed the GPSDO to trigger your scope and look at the output of the
> time base on one channel of the scope.  You could also look at the GPSDO
> on
> the other channel.  Then you could adjust your counter time base to
> 'freeze'
> the display.  Probably good to 'align' the counter time base but for long
> term comparison, probably better to use a counter and plot the difference.
>
> Joe
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Mark Spencer
> Sent: Saturday, July 24, 2010 12:29 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Basic question regarding comparing two frequencies
>
> Hello:
>
> Just for grins I decided to compare the frquency from my GPSDO to the time
> base
> in my 5328A counter.   
>
>
> I connected the 10 mhz time base from the counter to channel A of my 100
> Mhz
>
> scope, fed the 10 mhz signal from my GPSDO into Channel B and with a T
> adaptor
> also fed this signal into the input of the counter.    I scope to trigger
> from
> Channel B.  
>
>
> The drift betwen the two signals on the scope seems to match the error in
> the
> displayed frquency on the counter.  (ie. if the counter shows 9999.9998 it
> takes
> approx 5 seconds for the the wave form on channel A to slip a full cycle
> realitve to channel B.)  
>
>
> Is this a reasonable approach or is there a better way to compare two
> frequencies using a scope ?
>
> Best regards
> Mark Spencer
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>



_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.




More information about the time-nuts mailing list