dxAce wrote:

Someone else might chime in here on this one but if I'm not mistaken using the
coaxial cable in that fashion actually defeats the purpose as it should be
terminated in its characteristic impedance at both ends to be effective.

I was going to try a variation of that, by putting the matching transformer
at the long wire junction to the coax. We had a few warm days here, though
and the it's a mudhole back there, so I wait..



I seem to recall some effects of capacitance coming into play when used as
you've described, and what happens there is that the coaxial cable is simply
acting as a very long capacitor which might actually act as a block to some
frequencies.

Possibly. If I ever get energetic I'll connect a signal generator to the far
end and see what comes out on the radio side. I have an old scope here that
will go to 30Mhz, so it should be fine. Things don't seem too bad now, but I
have no way of knowing if they can get better until I try.



I'll have to look through the literature when I get a chance.
Depending upon how you have it hooked up you might not have noticed any
difference with a matching transformer if it was not attached properly.

Very true. I have no way of knowing to what degree the impedance
characteristics of the wire have been changed (if at all) by the single
point ground cable sheathing. That signal input test is starting to sound
better all the time.






mike

"m II" wrote in message news:CPgKd.47029$Ob.7617@edtnps84...
dxAce wrote:

Someone else might chime in here on this one but if I'm not mistaken
using the
coaxial cable in that fashion actually defeats the purpose as it should
be
terminated in its characteristic impedance at both ends to be effective.

I was going to try a variation of that, by putting the matching
transformer
at the long wire junction to the coax. We had a few warm days here, though
and the it's a mudhole back there, so I wait..



I seem to recall some effects of capacitance coming into play when used
as
you've described, and what happens there is that the coaxial cable is
simply
acting as a very long capacitor which might actually act as a block to
some
frequencies.

Possibly. If I ever get energetic I'll connect a signal generator to the
far
end and see what comes out on the radio side. I have an old scope here
that
will go to 30Mhz, so it should be fine. Things don't seem too bad now, but
I
have no way of knowing if they can get better until I try.



I'll have to look through the literature when I get a chance.
Depending upon how you have it hooked up you might not have noticed any
difference with a matching transformer if it was not attached properly.

Very true. I have no way of knowing to what degree the impedance
characteristics of the wire have been changed (if at all) by the single
point ground cable sheathing. That signal input test is starting to sound
better all the time.






mike

"m II" wrote in message
news:3L1Kd.153974$KO5.86186@clgrps13...
starman wrote:

I use stranded steel clothesline. Very strong and thick enough so that
the
senior members of the bird population can see it before they get maimed.


Do you run the steel wire all the way to the radio? If not, how do you
connect the lead wire such as copper to the steel antenna wire without
galvanic corrosion?



It's a temporary setup, So I just used a wire nut (Marrette) filled with
Penetrox, an anti oxidant grease, before it was put on the twisted coax
centre and the steel line. I positioned the closed end upwards, so that it
wouldn't collect rainwater.

A ground wire then runs down to the clamp on water pipe underneath. That's
the only side I have the coax grounded on. Then the coax runs through the
attic and down to the push button switch selector, which feeds the 'radio
of
the day'.

A matching transformer didn't seem to make much difference




mike