[TenTec] Resonant antennas

[Charles Greene]

Ken,

What you say is true, and you can point out some good examples of antennas 
that are not resonant that work better, and extended double zepp, for 
example.  But you have to qualify what you say.  You need a low loss feed 
line, like a open wire feed line for example.  Then you need a low loss 
antenna tuner, and you have to use it right.  I have seen antenna tuners 
with a 3 dB loss.  If you use a balun with an antenna tuner, it needs to be 
high efficiency too.  For our last field day, we used a tri band beam, a 40 
meter wire beam and a 135' Windom with a high efficiency balun at the top 
and fed with coax, which was broad band across 80, 40, 20 and 10.   Nary an 
antenna tuner in sight.

W1CG

At 06:01 PM 9/4/2004, you wrote:
>This is not a Ten-Tec specific topic, however.....
>
>>And, of course, he/she needs to know how to change bands and load the 
>>antennas (which ought to be resonant).
>While there may be some reasons that it is "nice" or "convenient" to have 
>antennas resonant, it is absolutely not necessary. I does not even make 
>them work better in some instances, or significantly better in most 
>instances. Yes, the transmitter should have a load which is not too far 
>from being the right impedance and low reactance (50 ohms for most rigs 
>these days) This can be accomplished using a tuner, making the antenna 
>system (antenna, feedline and tuner) not necessarily the antenna by 
>itself, resonant. Or it can be accomplished by using a wideband antenna, 
>such as a discone or log periodic, that has such a broad flat impedance 
>curve that it can hardly be called "resonant" at all. A lossy antenna ar a 
>dummy load is another way, but of course not the best.
>
>Ken N6KB
>
>
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