[TowerTalk] Perfect Field Day beam?

[Pete Smith]

At 10:57 AM 5/3/1999 -0400, Tom Rauch wrote:
>
>Hi Pete,
>
>> >Somewhere almost 5 dB (69%) of the applied power is missing.
>> 
>> Does this necessarily follow?  Trap losses surely aren't the only
>> mechanism at work here.  I suspect I could all too easily build a monoband
>> yagi that would work just as well (or badly) as a TA-33.  Why couldn't
>> element spacing compromises, real-world traps, etc., all lead to a net
>> deterioration in both pattern and F/B?
>
>If an antenna had no noticeable F/B, and the same F/S as a dipole, 
>then we can reasonably expect the system to have very little gain.
>
>I certainly know that isn't the case with a properly functioning TA-
>33.
>
>You be amazed at how hot an inductor gets (especially in a closed 
>cylinder) with even 30-40 watts of heat!

Tom, I'm certainly not arguing the old "trap losses" line, nor am I
suggesting that ohmic losses account for the TA-33's behavior.  What I am
suggesting is that cancellation effects resulting from incorrect spacing or
other design factors could lead to an antenna that has both F/B and minimal
forward gain, without having to blame it on low efficiency.  If not, why not?


73,  Pete N4ZR
Loud is good


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