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Old September 9th 04, 03:14 AM
Jack Painter
 
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Thanks Craig - and if you could, please elaborate on these design
considerations:

The antenna is not erected yet - still planning. I would choose a 1:1 balun
if I used one at all with an end-fed inverted-L configuration. But if I
configure the antenna as a sloper (same L-shape) and top-feed at the angle
point, then I thought a 4:1 balun could help make 2182khz tunable on an
antenna with dipole properties that is really too short (would have to be
107' each leg not 107' total, which is about all I can get at that
location). Of those two choices, I had not intended to use ladderline for
either, but would consider it if some benefit was possible. Ideally, the
antenna would be desireable to cover 2-20mhz. No compromse on the 2182 end
is worth the upper bandwidth though, with 5.7 & 8.9 mhz the other
requirements that should not unduly strain a tuner under high tx power. The
antenna would be primarily for 2182 - 4125 khz.. Thanks for any help.

Jack

"Craig Buck" wrote in message
news:Y6O%c.7112$OZ6.5222@okepread06...
You can go with ladder line right out of the tuner or to a short piece of
coax to a balun, then to ladder line. I have about ten feet of coax to a
1:1 balun outside. The coax is easier to get out of the house and away

from
things that might unbalance the ladder line. Loss on such a short piece

of
coax is negligible even at high SWRs on HF.

Whether you use a 4:1 or 1:1 depends on the antenna and feedline. I use a
1:1. Your antenna will be the "right" length so the impedance at the
transmitter end won't be too far off from 70 ohms. A 4:1 balun would be a
mistake as it would lower the impedance making it harder to match the
transmitter.

I have to ask, "Why are you using ladder line?" Usually it is only used
when the antenna has a high SWR and we want to avoid losses in the coax.
You won't have much of a mismatch, if any. I would think you would go

with
coax, you might not even need a tuner.
--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64


"Jack Painter" wrote in message
news:UuM%c.173651$Lj.145677@fed1read03...

"Craig Buck" wrote

I use a top center fed L. One side is horizontal and the other side

is
vertical. Fed at the top center with ladder line. Cebik has several
articles on his site about center fed Ls. No ground plane, horizontal
and
vertical polarization, fewer nulls in the pattern. Very nice

I think the center feds make a lot more sense for multiband operation.

--
Radio K4ia
Craig "Buck"
Fredericksburg, VA USA
FISTS 6702 cc 788 Diamond 64


Hi Craig, is that fed with ladder line right out of the tuner? I'm

hoping
there is a best-fit arangement from my tuner to an inverted-L with

either
a
top-fed through a 4:1 balun or end-fed without a balun. In either case

the
intention is to cover 2182khz with a 107' 1/4~ L. Any suggestions on

the
best arrangement for that work?

Thanks,

Jack
Virginia Beach VA