Topband: broadbanding an L
Bob Eldridge
r.c.eldridge at ieee.org
Fri Dec 31 16:21:36 EST 2004
At 19:07 2004-12-31 +0000, you wrote:
>Don't forget that sometimes increased bandwidth indicates losses within
>the system.
That's true, but sometimes a tradeoff is useful. Last week my horizontal
loop showed 1.5 SWR right across the band. It is normally about 25 kHz
bandwidth. Signals didn't sound bad, and I worked a couple of JA's.
When it was light I plodded around in the snow and found the wire had
drooped and was in the branches of an evergreen. I freed it and it came
back to normal. But it had worked.
>infamous Maxcom antenna matcher, which was essentially a dummy load
with >nonresonant antenna wires attached. The wires radiated enough rf to
produce a >detectable signal . . .
On some bands that antenna was only half an S point down from a dipole. A
terminated rhombic loses about a third of the applied power in the termination.
The resistor gets warm in a T2FD, but the radiation is more than "detectable".
Just depends what the main objective is. The loss is there, but sometimes
it helps.
Bob VE7BS
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