[TenTec] 80M LOOP

[Sinisa Hristov]

Rick Westerman wrote:
 

> I stand by my statement that at all the clubs I've belonged to,
> the loop has outperformed the dipole for the type of operations
> needed for Field Day contests.  That of course means to work as
> many portable stations as possible, the majority of whom are in
> the same country (DL in my case).  I'm not talking about one
> dipole that didn't perform - I'm talking about many dipoles that
> didn't perform. Actually they did perform but the loop simply
> performed better.  The 80/40 meter difference was small and
> sometimes the dipole was equal, but it was almost never stronger.
> Usually the loop was stronger.  On the higher bands, the loop
> stomped the dipole.


Did you investigate WHY?

Antenna A (as sophisticated as it can be)
can outperform antenna B (as UNsophisticated as it can be)
in ALL directions (both azimuth and elevation),
ONLY if antenna B has too much loss,
i.e. transforms most of RF energy into the heat instead of waves.

All 100 % efficient antennas have exactly the same AVERAGE "gain",
i.e. there is no such thing as "gain" per se - what the word actually
describes is simply focussing of radiation.

This means that antenna A can produce a few dBs more
in a selected direction ONLY by producing 
several dBs less in ALL the other directions.

In essence, that is the law of conservation of energy.
And I don't think you'd claim encountering a perpetuum mobile.

Properly constructed antennas have almost perfect efficiency,
with loss on the order of 0.1 dB or less.

Therefore, if your loops were always better than dipoles,
then the dipoles were bad, very bad, plain and simple.

Can we agree on this before proceeding any further?


> I could buy into your theory if this had only happened once or
> twice. But it happened many, many times.

Obviously a bad method of dipole construction
did not become a good one by pure repetition.


> All of these articles and my experience with it (which spans 25
> years) point towards this antenna out-performing a dipole - but I
> couldn't tell you why!

That's a very convenient and powerful method :-)

But it has a minor problem of not being scientific.
And although we are not scientists, that doesn't enable
our antennas to work better than the laws of nature permit.


73,

Sinisa  YT1NT, VA3TTN