On 1/22/2014 5:32 PM, Irv Finkleman wrote:
Q. Is there a relationship between the efficiency of an antenna and the
received signal strength?


Definitely. Antenna efficiency works both ways - a less efficient
antenna will affect both transmit and received signals.

Just pondering on the matter. Because I have to operate with
restricted space antennas, usually with low efficiency, I wonder how
much of a relationship exists between Efficiency and Received Signal
Strength?


Just as much as between efficiency and transmitted signal strength.

This leads to more questions such as how much do radials contribute
to efficiency?


That depends on a lot of factors such as number of radials, length,
height above ground and ground conductivity, for start. Each situation
is different. But generally, for antennas such as 1/4 wave verticals,
radials will help.

IF that isn't enough, how much do radials contribute to the bandwidth?


See above.

And...

And...

I'm never to old to learn, but I am old enough that a lot of mathematical
mumbo jumbo and Smith Charts tend to confound me!


Unfortunately, the only way to predict how an antenna is going to work
in a specific situation with any accuracy is with math and Smith Charts.
So you can use the "tried and true" method - put it up and see what
happens

For starters, I will be operating using an MP-1 antenna and a Yaesu
FT-817ND. I also have an MFJ-931 Artificial Ground, but propose
attaching the radials to the feedpoint on the MP-1. I intend to cut four
radials for 20M and spread them around the base of the antenna in
my room, and once the weather warms up, I'll try the antenna out on
the balcony with the radials spread around whatever real estate it
provides.


Not an ideal situation, but you do what you can.

Thanks for any input on the matter....

Irv VE6BP

RADIATE OR DIE TRYING!









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