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[TowerTalk] FW: In Shack Tuner Vs. Remote Tuner for Multi-Band Antennas

To: towertalk@contesting.com
Subject: [TowerTalk] FW: In Shack Tuner Vs. Remote Tuner for Multi-Band Antennas
From: Chuck Smallhouse <w7cs@theriver.com>
Date: Wed, 07 May 2014 01:34:39 -0700
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
This interesting subject has so far has been educational !

But the original subject , I thought, would be discussed about shack versus remote antenna tuners, which is a design project that I am interested in.

My feeling is that most, if not all, antenna variable compensating units (tuners), would be better served by installing them as close as physical and mechanical possible to the antenna feed point, They could then "Match" the antenna to 50R and allow VSWR free, and almost lossless, coax to transport the signals to and from the antenna, Of course this technique/concept works best when used with multi band/frequency antennas,

At present I'm loath to find a QRO or better yet a QRO++, tuner suitable for remote weather resistant mounting, other than the MFJ 998RT, and it's only single ended. I'd prefer one that also made the conversion from balanced input to 50R output.

You may skoff, but I actually have an installed B&W style, MIL Spec, folded dipole, that's 180' in overall length (using MILSpec SS twisted multiple strand wire) and works quite well on especially 160 meters and up. This is in spite of the 800R power resistor in the center of the far leg of the B&W dipole, I feed it with <100' of 7/8" Helix. This keeps the miss match VSWR loss, caused by the coax, quite low even on the higher bands. The standing waves on the incoming 7/8" coax are then tuned/matched by my HPA's auto-tuner. I could actually mount such a tuner right at the feed point balun (it probably needs to be replaced with a higher powered one), or I can put the balun & tuner at the end of about a 20' run of ladder line, near the bottom the tower, for easier access, BTW, this relative sort tower that holds up the center of B&W. dipole, and a long boom 6M beam, is on top of a small 30' hill. This is at 5K' elevation, with mostly a negative horizon. in the important directions.

Q.: In keeping with the true subject of this O.T., will this be an advantage over, only using the auto tuner in my PW-1 PA ? And why aren't there more remoteable, QRO, WX proof, auto tuners, on the market ?

Thanks for any comments or advice,  73,  Chuck  W7CS

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