TopBand: Beverage terminating resistor

[w8jitom@postoffice.worldnet.att.net]

> From:          Bill Hohnstein <k0ha@navix.net>

Hi Bill,

> modeling of a Beverage that I just put up today shows that chosing
> a termination resistor for best F/B produces a 58 degree wide area
> with a 20 dB minimum null range.  My termination resistor chosen
> shows a 65 degree wide area with a 20 dB minimum null range and the
> four pattern nulls all having greater attenuation at their azimuths
> than the similar nulls on the optimum F/B pattern.

Any way we slice it, that is a 12% pattern null change that 
probably amount to a fraction of a dB directivity. 

In my experience, termination adjustmet changes null depth much more 
rapidly than null location. Is that what the models show? Since 
null depth *seems* to change much faster than null location, and any 
mistermination adds frequency sensitivity, I've always assumed the 
best termination to be a "flat" termination.

73, Tom W8JI

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