[TowerTalk] elevated short vertical dipole orquarterwave monopole?

[Juan M. Chazarra EA5RS]

I have a Cushcraft X-7 which is not a pure LPDA but uses a log cell.
It is fed thru a 4:1 balun and I route the coax along and taped over the
boom (the tx line is below the boom).

Except on 10m where I do have some unknown problem (F/B is very very
poor), I think I have no current on the outer shield of the coax. I
think this is the case as pattern is very clean and I measured >35 dB
dip off the ends of the antenna compared to front.

73 Juan EA5RS


-----Mensaje original-----
De: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] En nombre de Steve Katz
Enviado el: viernes, 03 de diciembre de 2004 19:36
Para: 'Tom Rauch'; Michael Tope; Jim Lux; Guy Olinger, K2AV; TowerTalk
Asunto: RE: [TowerTalk] elevated short vertical dipole orquarterwave
monopole?



> When I had a gamma matched Wilson 20M yagi, the common mode
> voltage on the coax was so high the coax actually arced
> between the tower leg and the coax shield. 
> 
> ::Tom, you posted something recently somewhere about LPDA mfrs
> recommending running the feedline along one of the excited booms and
> stuff.  Yep, Tennadyne recommends this.  I've also seen it recommended
to
> run the coax inside one of the excited booms, where an LPDA's elements
> didn't go through the booms, leaving them hollow.  In lieu of this,
which
> seems wrong to me too, how do you recommend routing xmsn line to an
LPDA?
> "Hanging down from the feedpoint for 1/2WL" isn't going to cut it for
most
> of us, that would be a 33' rotor loop...73 de Steve WB2WIK/6
> 
> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers",
"Wireless
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041
with
> any questions and ask for Sherman, W2FLA.
> 
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_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
any questions and ask for Sherman, W2FLA.

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