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Old July 20th 08, 04:53 PM posted to rec.radio.amateur.antenna
Ed Cregger Ed Cregger is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 236
Default Window ladder line losses ton environment vs coax losses


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...
A very 'general' answer is that coax will have less 'variable' loss
from being near stuff than 'ladder-line' because of the way it's
constructed (and why it was originally made anyway). If that's the
only consideration you have to think about, then it's a fairly simple
question to answer. When you start thinking about the other
properties/characteristics of coax/ladder line, the answer isn't quite
so simple any more. (I like using ladder line, but I seriously doubt
if I try running it in a vehicle, see what I mean?)
- 'Doc


I've found that a 10ga loaded with small shot will clear out most
leaves that might interfere with ladder line. Large twigs, limbs,
etc, require larger shot. Gotta get that angle right though, that's
the hard part. Not to mention the neighbors...
(No, I'm really not that dumb. Just depends on how frustrated I am.)


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Twinlead/ladder line comes in handy for situations such as mine.

I'm running a Van Gordon All Bander dipole. Fed with 450 ohm twinlead, which
it is, I can tune virtually anywhere from 160 meters to 6 meters as long as
I'm tolerant of a bit of RF in the shack. To me, the versatility of being
able to transmit anywhere I'm legal from six meters down to 160 meters is
well worth the pattern changes and other characteristics of the
dipole/twinlead combination.

Just be aware that you can enter into situations with this setup that can
start a fire by arcing to an interior/exterior object if a kilowatt or more
is used. Maybe even less power, come to think of it. I set a curtain on fire
once this way. That was an interesting sounding transmission after I saw the
curtain ablaze.

For me, this setup works the best for my circumstances.

Feed this same antenna with coax and you'll run out of tuner swing long
before you'll match the same antenna to the same bands as matched with
twinlead. Chances are you'll also punch a hole through the coax' dielectric
insulator, which leads to breakdown (internal arcing) at even lower voltages
later on. Coax has its uses and I use plenty of it for the higher bands.
Just not on the low bands since I must make do with my single Van Gordon All
Bander antenna.

I apologize for not sounding as scholarly as many of you, but I'm getting
old and don't have time for that nonsense. 8)

Ed, NM2K