Topband: beverage impedance

[i4jmy at iol.it]

> I've been working on some methods to determine proper Beverage termination. 

The SWR flatness is not a bad choice. Most practical method is to chose a termination in such a way the impedance fluctuation (SWR) with frequency is minimal.

> Some time domain and some frequency domain. Has anyone tried a TDR on a 
> Beverage?

For other purposes than measuring a beverage, already 20 years ago I used a microwave time domain network analyzer. With transmission lines, displayed bursts gave some information about the kind of discontinuity, while the point (the time) where the discontinuity appeared told how far it was along the line.

73 and season greetings,

Mauri, I4JMY

> I would use a pulse generator with a 10 ns rise time and a pad to set the 
> output impedance to around 500 ohms. A 50 MHz oscilloscope is plenty fast to 
> look at it. This should give a resolution of <10 feet and allow one to see how 
> the impedance varies along the length of the Beverage. A simpler method is to 
> operate the Beverage as a Transmission Line Pulse Generator and one can get the 
> same information. If anyone wants to give this a try I can explain it and how 
> to interpret the waveform.
> 
>    Dave WX7G