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FW: [TenTec] Aux Antenna

To: <tentec@contesting.com>
Subject: FW: [TenTec] Aux Antenna
From: rohre@arlut.utexas.edu (rohre)
Date: 16 Sep 1998 15:48:30 -0500
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

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.


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