[time-nuts] AC Connector On HP 5061B

Jeffrey Okamitsu w3kl at w3kl.com
Fri Oct 3 21:44:25 UTC 2008


In this case, cable quality is critical and controlling cable characteristics (as a function of temperature, humidity, etc.) is also critical.
 
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Friday, October 3, 2008, 4:58 PM

Tom Van Baak wrote:
>> On the DA you will want to ensure all your output cables are of
>> identical length as this will ensure that all signals are in phase at
>> the timebase input(s).   It's a small thing really a fraction of a
>> picosecond but it's there and easily compensated for.
>>     
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb
>
>   
Tom

Another example of a case where the electrical length of a cable can be 
important is in precision frequency distribution systems.
Trimming the cable to the right length (one way propagation delay equal 
to an odd multiple of half the signal period) for the frequency in use 
minimises the effect of load and source mismatch.

Bruce

_______________________________________________
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_lists.febo.com mailing list