TenTec
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FW: [TenTec] Aux Antenna

To: <tentec@contesting.com>
Subject: FW: [TenTec] Aux Antenna
From: kf5mc@flash.net (Joseph Pursley)
Date: Thu, 17 Sep 1998 16:04:10 -0500
How about the old 2.5 mh choke to ground trick...............

rohre wrote:

> Since one satisfied user already posted that it works, here is the math to
> show how little power it costs.
> _______________________________________________________________________________
> To: seweber@netnitco.net
> From: rohre on Wed, Sep 16, 1998 3:45 PM
> Subject: RE: [TenTec] Aux Antenna
>
> Steve,
> Look at the difference in 50 ohm antenna vs. 100,000 ohms.  You would have a
> current that was very small being drained from the transmitter power going to
> 50 ohms. The transmitter would primarily see the 50 ohm antenna, or whatever
> the antenna low impedance is, and hardly miss the minute drain to the 100000
> ohm ground.  Consider that your insulators on the antenna when wet might be in
> the megohm range, where you would lose a microwatt of power.
>
> Lets say you have 50 watts from the TX.  The ratio of the antenna impedance to
> the resistor is 1/2000.  If it were 1/1000, it would lose 50 mw, but at
> 1/2000, it is only 25 mw.  If you run QRP, just make the resistor something
> larger like a meg ohm.  The idea is just to have some bleed off path for
> static voltage.  In case of direct hit, it is toast anyway or for any size
> resistor, so it can be a low wattage carbon, but best sealed in epoxy so it
> won't get wet.
>
> Stuart
>
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