system degradation question
 

In message , rb writes
Got a station antenna setup. I have twinlead up to 140' per side dipole.
I have a desk, facing a wall. Window over to the right. Right now, I
have coax coming out of my antnenna tuner, going outside, through the
window, to a setup to feed balanced line.

For years, I've thought about what would happen if I brought balanced line
into the house.

I've got a metal filing cabinet between window and ham shack. I'd have
about 5' of line from my tuner, going around the cabinet, and finally
getting to the window.

How much performance degradation would this give me to do it in spite of the
metal cabinet? I know for years they say: don't let twinlead come near
metal objects. This would be doing that. Wonder how much degradation I'd
suffer if I did that?

As they say, "Suck it and see" (especially if it's easy to try).
Keep the feeder as far as possible from the filing cabinet (rotating it,
if you can). [No, not the filing cabinet.]

If you don't try it yourself, and report back here what your findings
are, in six months from now, this thread will still be going strong.
--
Ian

system degradation question
 

Got a station antenna setup. I have twinlead up to 140' per side dipole.
I have a desk, facing a wall. Window over to the right. Right now, I
have coax coming out of my antnenna tuner, going outside, through the
window, to a setup to feed balanced line.

For years, I've thought about what would happen if I brought balanced line
into the house.

I've got a metal filing cabinet between window and ham shack. I'd have
about 5' of line from my tuner, going around the cabinet, and finally
getting to the window.

How much performance degradation would this give me to do it in spite of the
metal cabinet? I know for years they say: don't let twinlead come near
metal objects. This would be doing that. Wonder how much degradation I'd
suffer if I did that?

system degradation question
 

On May 23, 2:53*pm, "rb" wrote:
Got a station antenna setup. * *I have twinlead up to 140' per side dipole.
I have a desk, facing a wall. * Window over to the right. * Right now, I
have coax coming out of my antnenna tuner, going outside, through the
window, to a setup to feed balanced line.

For years, I've thought about what would happen if I brought balanced line
into the house.

I've got a metal filing cabinet between window and ham shack. * I'd have
about 5' of line from my tuner, going around the cabinet, and finally
getting to the window.

How much performance degradation would this give me to do it in spite of the
metal cabinet? * * I know for years they say: * don't let twinlead come near
metal objects. * This would be doing that. * Wonder how much degradation I'd
suffer if I did that?

Probably none. Performance might actually increase slightly if the
coax to twin lead connection is lossy. I'm not a fan of running coax
to
twin lead. If I use a tuner, I run twin lead or ladder line the whole
route.
The "twin lead near metal" issues are often overblown.
Like Ian says, try it and see what happens.

system degradation question
 

On Sun, 23 May 2010 12:53:48 -0700, "rb" wrote:

Got a station antenna setup. I have twinlead up to 140' per side dipole.
I have a desk, facing a wall. Window over to the right. Right now, I
have coax coming out of my antnenna tuner, going outside, through the
window, to a setup to feed balanced line.

For years, I've thought about what would happen if I brought balanced line
into the house.

I've got a metal filing cabinet between window and ham shack. I'd have
about 5' of line from my tuner, going around the cabinet, and finally
getting to the window.

How much performance degradation would this give me to do it in spite of the
metal cabinet? I know for years they say: don't let twinlead come near
metal objects. This would be doing that. Wonder how much degradation I'd
suffer if I did that?


For my 80 meter dipole, I have 92 feet of twinlead running around the
roof, and through the window, to my tuner -- it passes a few metal
pieces here and there, and I can't see any problems. I'd say give it a
try -- it's the only way to find out.

I use one of the MFJ window feedthrough panels to get the twinlead
indoors -- they work very nicely.

bob
k5qwg