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Old January 11th 06, 05:33 PM posted to rec.radio.amateur.antenna
Richard Clark
 
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Default Inverted-L Antenna And Close Proximity Coax ?

On Wed, 11 Jan 2006 07:40:52 -0500, "Robert11"
wrote:
The easiest way by far for me to get the coax to the receiver is to run it
up from the Balun to my second floor where the receiver is.

If I run it upwards "right alongside" (or even tied to) the active vertical
section of the antenna, will I have any problems ?
Remember, this would be coax, and I do receiving only.

Guess I'm worried about if the grounded shield of the coax presents some
kind of ground element right next to the active element ?


Hi Bob,

There is no inherent advantage in the inverted L except it being a top
loaded vertical with some horizontal polarization properties (being
unbalanced and all). You can save yourself some bewilderment by
driving the bottom directly into ground and simply connecting your
coax right at your second floor window with the coax shield connecting
to the wire going down, and the coax center to the wire going up and
to the tree. When lightning suggests itself, unconnect the coax from
your receiver and drop the coax out the window.

You will never notice the proximity of the wood siding, but you may
notice the proximity of house wiring that is in that wall. That
wiring may be carrying house noise (like a computer's monitor's hash).
However, that is best left for future investigation instead of
paralyzing you now.

Also, build an antenna tuner, or buy a very cheap, no-meter 3-knob Ham
tuner (less than $30). When you get into better antennas, you get
into overdrive possibilities from nearby AM stations (and I bet there
are a bajillion there in Mass). This is called "desensing" when those
stations (even when you are not tuned to them) overpower your radio
and drive the AGC so high, that you cannot hear weaker DX in the SW
bands.

73's
Richard Clark, KB7QHC