Mark Keith wrote:
Telamon wrote in message
I only looked at a few frequencies but those were near the frequency for
which the antenna was cut. Išm not worried about the other bands. I want
to know why I did not get a higher S meter reading on the band the
antenna was cut for. The transformer should have made for a better match
on 13 meters and it didnšt.
I mentioned in an earlier post that the folded dipole I modeled showed
a low Z. But after thinking about it, that didn't seem right. I had
always assumed most folded dipoles with two wires had about a 300 ohm
feedpoint. And double checking in a book, that seems to be the case. I
don't know why the antenna I modeled showed that, but I'll have to
look into it. But anyway, if you had a 300 ohm feedpoint, and used a
9:1 balun, you would end up quite low in Z to the radio.
A 4:1 would put you in the ballpark. But, I'd still prefer to use a
single wire dipole fed with coax for a single band dipole. No
transformer needed. Only a balun, and that can be a choke wound from
the coax. But again, as far as s/n ratio, not counting noise ingress
problems, any of them should work. MK
Hi Mark,
What software are you using for modeling? NEC engines do not like close wires
(perhaps NEC4 has dealt with this).
EZNEC or AO should handle the problem better.
Dale W4OP
for PAR Electronics, Inc.
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