[TowerTalk] Re: TopBand: Re: Sloped Beverage Terminations

Thu, 23 Oct 1997 10:27:19 +0000

> Perhaps part of the problem is that these beverages have run within
> about 50 feet of my tower, but I wonder if the assembled masses 
> could comment on the relative effectiveness of terminated vs un-
> terminated beverages?  The books all say that unterminated beverages
> differ from terminated ones mainly in that they are bidirectional,
> but I wonder if that is too simplistic and that there may be other
> factors at work? 

Hi Alan,

Bi-directional ASSUMES the antenna has zero dB reflection return 
loss. If the antenna has any loss at all, it will have F/B ratio.

I've measured Beverages here (GA, 4 mS/m ) and in Ohio (15-25 mS/m) 
and found the loss about 3 to 6 dB per 500 ft on 160.

That guaranties a minimum 3 to 6 dB F/B ratio without termination on 
a 500 ft wire and 6 to 12 dB if the wire was 1000 ft long.

You might have to keep the antenna away from the TX antenna also, or 
detune the TX antenna when on receive.

73, Tom W8JI

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