Agree,
Mick
----- Original Message -----
From: "Tom Rauch" <w8ji@akorn.net>
To: <TOWERTALK@contesting.com>; <n4kg@juno.com>; "MGB" <mgb4@address.com>
Sent: Saturday, January 05, 2002 8:47 PM
Subject: Re: [TowerTalk] Slopers from tower
>
> > > Even if the tower and yagi combination, at the feedpoint of the
> > > slopper, is not resonant the antenna can have a good SWR.
> > >
> > > All you do is change the length of the slopper, until the system is
> > > resonant.
> > >
> > I didn't want to get in this discussion, but since I stupidly started
> > it by mistakenly sending that C/C message to the entire list, I have
> > to comment on the above statement. The conception you can simply
> > change the length of wire on a 1/4 wave sloper to achieve a "good" SWR
> > is simply not true.
>
> I could have been clearer, and of course you are correct. It won't
> always work.
>
> What I tried to say is if REACTANCE at the tower connection point
> is a problem, you can cancel it by changing length of the slopper
> as LONG as resistance is within a reasonable match range. It does
> not matter of the tower impedance is reactive as long as the
> resistive part is very low, because slopper length can be tweaked
> to tune out reasonable amounts of reactance.
>
> If RESISTANCE is wrong at the final X=0 length of the sloper, you
> are stuck with the resulting SWR even when you make X=0. The
> critical thing is resistances, since problems can not be corrected
> by slightly changing sloper length.
>
> Of course you could use a matching transformer or stub, but let's
> not go here.
>
> My point was the tower does not need to present a X=0 for a low
> SWR, not that any impedance will work.
> 73, Tom W8JI
> W8JI@contesting.com
>
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>
>
________________________________________________________________________
This list is sponsored by the new eHam.net Store. When you buy products
like ICE filters, Array Solutions StackMatch, or M-Squared Antennas from
the eHam Store for the same price you pay direct, a portion of the sale
price goes to support this list. Check it out at http://www.eham.net.
-----
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