Why bother with all that? What's wrong with putting a wattmeter in the line
between the amp and the antenna and just tune the amp for full smoke? Or
just use your field strength meter located in the shack and use that for
maximizing the output.
Bob W6TR
----- Original Message -----
From: "p.haire" <jhaire@bellsouth.net>
To: <towertalk@contesting.com>
Sent: Sunday, November 12, 2006 10:24 PM
Subject: [TowerTalk] Sensing antenna and feed for maximum tune up
>I am going to tilt over my tower and check out my tribander before winter
>gets too bad.
>
> While it is down, I would like to put a sensing antenna near the driven
> element to use as a pick up probe and with an rf voltmeter or field
> strength meter tune for mjaximum radiation from the driven element.
>
> I have seen pictures of towers with sensing antennas but I don't know
> anything about it. I can't find anything on the internet about sensing
> antennas for ham radio.
>
> I have several tv antenna elements that are old but in mint condition. I
> plan on mounting one horizontal on a boom at the top of the tower. The
> triband is on a mast 5 feet above. Between the triband and the top of the
> tower is a hinged swinging boom that holds the open wire feed of the
> driven element out from the tower as the antenna is rotated. The boom at
> the top of the tower holds a shunt fed wire that feeds the tower and a
> pulley for a delta loop. I plan on cutting the tv element down to about 1
> foot on each side of its insulator - so it will be a 2 foot dipole. Does
> this sound like a ball park lenght for the dipoloe?
>
> I plan on feeding the sensing antenna with 300 ohm line down inside the
> tower to a balun at the bottom of the tower. I will use an air balun from
> Orr's beam antenna hand book p161. From the base of the tower to the
> operating position will be coax. I built a field strength meter years ago
> but only used it over time as an rf voltmeter.
>
> Does this sound logical because I am not sure of what I am doing.
>
> Any suggestions, ideas or thoughts would be greatly appreciated.
>
> Thanks Paul WA5MUE
>
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