[Antennas] J-Pole

Thu Sep 30 08:42:02 EDT 2004

Then again what is the system used for? Is it a test bed for 
experimentation? Or is for amateur radio operation?
>From: "W1GOR" <W1GOR at Maine.RR.Com>
>To: <antennas at mailman.qth.net>
>Subject: Re: [Antennas] J-Pole
>Date: 2004年9月29日 15:29:15 -0400
>>John...
>>We knew all of that... But anything other than coax is impractical from a
>measurement standpoint... How much test gear exists that will provide
>reasonable accuracy with ladder-line..? With the exception of ancient
>LECHER WIRES, I can't think of any...(smile)
>>73, Larry - W1GOR
>>>----- Original Message -----
>From: "John Tait" <bravo at iol.ie>
>To: "Joe" <nss at mwt.net>; "W1GOR" <W1GOR at maine.rr.com>
>Cc: <antennas at mailman.qth.net>; "Durwydd MacTara" <durwydd at hotmail.com>
>Sent: Wednesday, September 29, 2004 1:18 PM
>Subject: Re: [Antennas] J-Pole
>>> > No.. I don't think he's kidding.. The whole point of open wire feeeder 
>is
> > that it has very low loss. It is the most efficient feeder type that's
> > available to us. Line loss increases with frequency, with SWR,and with
>line
> > length, so VHF/UHF antenna system have the most to gain by using open 
>wire
> > line. Good quality "Ladderline" is a less efficient feeder than proper
>open
> > wire line, but has less loss than coax..'specially if SWR is high.
> > However.. coax is much simpler to deploy than open wire line, and 
>good
> > quality hardline has acceptable losses so long as SWR is low, and 
>lengths
> > reasonable. Most of us settle for that, and put up with the losses. We 
>can
> > compensate for loss of transmitted power by using a linear amplifier, 
>and
> > for RX loss with a good low noise mast head preamp.
> > 73
> > John EI7BA http://www.iol.ie/~bravo/
> >
> >
> > >
> > > W1GOR wrote:
> > >
> > >> Ladder-Line for VHF/UHF...? You've gotta be kidding..!
> > >>
> > >> 73, Larry - W1GOR
> > >>
> > >> ----- Original Message -----
> > >> From: "Durwydd MacTara" <durwydd at hotmail.com>
> > >> To: <Antennas at mailman.qth.net>
> > >> Sent: Tuesday, September 28, 2004 10:20 AM
> > >> Subject: [Antennas] J-Pole
> > >>
> > >> > I have a homebrew 2M/70CM J-pole 50 ft. in the air for use with a 
>5W
> > >> > HT.
> > >> Am
> > >> > currently using RG-213 for feedline. i am wondering if it is worth
>the
> > >> > effort to switch the feed to ladder line, and if so how to do it?
> > >> >
> > >> > "Carpe` Diem!"
> > >> > Durwydd MacTara
> > >> >
> >
> >
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