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Old December 1st 13, 11:17 PM posted to rec.radio.amateur.antenna
John S John S is offline
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First recorded activity by RadioBanter: May 2011
Posts: 550
Default Turning a 1/4 wave vertical upside down

On 12/1/2013 2:42 PM, amdx wrote:
On 12/1/2013 11:48 AM, Irv Finkleman wrote:
Before too much theorizing takes place, why not try just placing it in a
convenient location in the house -- you might be pleasantly surprised.
If that doesn't work, then, and only then, it becomes a technical
problem.

Irv VE6BP


That's good advice, except I have three different audio inputs that all
land where I now have the transmitter.
Besides, we like technical problems! :-)

After my last response to Jeff when I measured the output voltage, I
just realized I can check the loss through the LPF. Hot dog! Can't
wait to get home.
Mikek


Don't fool yourself. A 10x probe has maybe 10pF capacitance. What is
that reactance at 100MHz? About maybe 160 ohms? How will that affect
your measurement?

As far as an upside down vertical is concerned, you should get the free
copy of EZNEC and study what it is that you want to achieve. The ground
characteristics and the height above it is what determines the so-called
angle of max radiation. Height alone is sufficient to lower the angle.
For example, a perfectly conducting earth has an angle of maximum
radiation of zero degrees. Think about it.