[time-nuts] Delay through GPS antenna splitter/amplifier -- an answer, and a question

[Rob Kimberley]

Now that is obsessive!!

:-)) 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Dr Bruce Griffiths
Sent: 12 March 2007 22:39
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Delay through GPS antenna splitter/amplifier -- an
answer, and a question

Tim Shoppa wrote:
> John Ackermann N8UR <jra at febo.com> wrote:
>   
>> But we're time-nuts... we DO worry about those things. :-)
>>
>> While we were at it with the network analyzer, we did FDR (frequency 
>> domain reflectometry) to measure the cable delay to the antenna, and 
>> I spent yesterday making up six matched cables to go from the 
>> splitter to the receivers -- they all test within about 1 nanosecond of
each other.
>>
>> Obsessive compulsive?  Me?
>>     
>
> At the lab I worked at in the 80's, all the cables hanging on the 
> wall-racks were calibrated and labeled in nanoseconds.
>
> But... after the ECL signals got turned into TTL, we just didn't care 
> anymore :-).
>
> Tim.
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
>   
John

Your not quite obsessive enough.
The cable delays (including the antenna to splitter cable) should also be a
multiple of half the signal period to minimise the effects of residual
mismatches at either end of the cable.

Bruce

_______________________________________________
time-nuts mailing list
time-nuts at febo.com
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts