Topband: Beverage antenna

Herb Schoenbohm herbs at vitelcom.net
Wed Jan 19 04:57:07 PST 2011



On 1/18/2011 1:50 PM, Ben Wasilauskas wrote:
> Was wondering since the matching unit for the beverage is 9:1, would it be possible to feed the antenna with 450 ohm ladder line directly? Would this lessen the effectiveness of the beverage?
>
> Thanks,
>
> Ben, K4GHS
>
No problem as long as you you watch the balance with respect to ground 
and provide for a balanced to unbalanced transition at both ends.  Yet 
RG-6 is much much cheaper than 450 ohm ladder line, another 
consideration.  however if you feed a flag or pennant with a 1/4 wave 
electrical of twin lead, you are looking into a balanced load.  With 
proper feed line dress and some twists along the way this will work well 
by transforming 75 ohm to about 950 ohm, actually 300 ohm twin lead will 
get you closer to the impedance  required by the flag or pennant.  You 
will still need a 1:1 transformers where the balanced line approaches 
the shack.  But this is a piece of cake with a few primary and 
secondary  turns through a binocular ferrite core.

Herb, KV4FZ


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