Got a Radio Works choke balun I'd like to use for feeding ladderline out of
an unbalanced tuner.

The balun has coax fittings on each end.

Ladderline doesn't adapt well to coax interfaces.

What's the best way to put ladderline to my balun coax fitting?

I can kluge a PL-259 plug onto the ladderline.

I guess I could also stick one side of the ladderline in the center hole of
the chassis coac fitting, and clamp the other side to the threaded part of
the chassis fitting.

Ideas solicited.

Got a Radio Works choke balun I'd like to use for feeding ladderline
out of an unbalanced tuner.


I'm sure others here will correct me if I'm wrong, but I believe that
what you want to do is a very bad idea. Baluns are not meant to operate
under the potential very high SWR conditions you are likely to have on the
output of your tuner. Damage to the balun is likely. Besides, what is the
point of a balun on your tuner's output if you are using ladderline,
anyway?


Ed K7AAT

Ed wrote:

Got a Radio Works choke balun I'd like to use for feeding ladderline
out of an unbalanced tuner.

I'm sure others here will correct me if I'm wrong, but I believe that
what you want to do is a very bad idea. Baluns are not meant to operate
under the potential very high SWR conditions ...

It depends on whether the very high SWR is on the ladder-line
side or on the coax side. :-)
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote in
. net:

Ed wrote:

Got a Radio Works choke balun I'd like to use for feeding ladderline
out of an unbalanced tuner.

I'm sure others here will correct me if I'm wrong, but I believe
that
what you want to do is a very bad idea. Baluns are not meant to
operate under the potential very high SWR conditions ...

It depends on whether the very high SWR is on the ladder-line
side or on the coax side. :-)


Well, he said "OUT of an unbalanced tuner" so I assume that's the
ladderline side.

Ed K7AAT

Ed wrote:
Cecil Moore wrote:
It depends on whether the very high SWR is on the ladder-line
side or on the coax side. :-)

Well, he said "OUT of an unbalanced tuner" so I assume that's the
ladderline side.

Yes, and with a reasonable limit, the SWR on the ladder-line
doesn't matter. IMO, 25:1 is no problem for ladder-line.
--
73, Cecil http://www.qsl.net/w5dxp

On Mon, 07 Nov 2005 23:26:47 GMT, Cecil Moore wrote:


Yes, and with a reasonable limit, the SWR on the ladder-line
doesn't matter. IMO, 25:1 is no problem for ladder-line.

There must be a host of unstated assumptions behind that statement to
make it valid in a limited scenario.

Using TLDETAILS to work up a load of 16+j0 on 100m of Wireman551
ladder-line at 30MHz, the predicted VSWR varies between 25 at the load
end and a very modest 6.5 at the generator end, yet the predicted loss
is around 6dB. Some might not find that an acceptable loss.

Owen
--

Well, he said "OUT of an unbalanced tuner" so I assume that's the
ladderline side.

Yes, and with a reasonable limit, the SWR on the ladder-line
doesn't matter. IMO, 25:1 is no problem for ladder-line.


Correct, a high SWR is not an issue for ladderline, but the guy was
wanting to stick an apparently 50 ohm coax balun right there in between
his balanced tuner output and that ladder line. I would think a high
SWR, with some TX power, in that device might not do it much good.


Ed

Why are you using a choke at that point in the system? You should use
either a 1:1 or 4:1 current balun to go from coax to ladderline..and
keep the coax VERY short to minimize losses on it due to high SWR. A
choke is for something entirely different.

Jim/K2TL

wrote:
Why are you using a choke at that point in the system? You should use
either a 1:1 or 4:1 current balun ...

A properly designed choke performs the function of a
balun very well - witness the W2DU choke-balun. If
the common-mode currents are choked off in the coax
direction, they must necessarily flow in the ladder-
line direction.
--
73, Cecil http://www.qsl.net/w5dxp

RB wrote:
Got a Radio Works choke balun I'd like to use for feeding ladderline out of
an unbalanced tuner.

The balun has coax fittings on each end.

Sounds like it is actually a UNUN.

I can kluge a PL-259 plug onto the ladderline.

That will work. I usually just splice a short piece
of coax to the ladder-line.
--
73, Cecil http://www.qsl.net/w5dxp