[time-nuts] T.I. experimenting - newbie question

[Bruce Griffiths]

Joseph Gray wrote:
> Interesting followup. With the exact same setup, but replacing the tee
> with a Wenzel power divider, I get 18.6 ns.
>
>    
Resistive or rf power divider?
Using the latter may result in significant reflections.
> On Sat, Apr 2, 2011 at 7:42 PM, Joseph Gray<jgray at zianet.com>  wrote:
>    
>> I have a borrowed HP 5328A with the Universal Module. I'm using
>> averaging mode and auto triggering. Counter does not have the OCXO
>> option. I'm using the internal oscillator, not locking to my GPSDO.
>>
>> I was just messing around with a length of Belden 9273 and the 100 KHz
>> square wave output from my Spectracom distribution amp. Start signal
>> is the 100 KHz signal. Using a tee, the stop signal is the same 100
>> KHz after passing through the length of coax. I'm reading 18.9 ns. The
>> coax specs give a VOP of 66%. This should calculate out to a length of
>> 3.74 M. When I measure the coax, I get 3.8 M.
>>
>> I am including the BNC connectors in my length measurement. If I
>> subtract them, I'm much closer to my calculated length. Should the BNC
>> connector lengths be included or not? Or, is the measurement I'm
>> getting as good as it gets with this HP counter?
>>
>> Joe Gray
>> W5JG
>>
>>      
>    
Bruce