Ian wrote:
"John" wrote in message
. au...
My question is how do they work?. If they are detecting electrical fields
how does increasing source impedance by 100,s of megohms improve things?.

Pardon? The coating or conduit shouldn't affect the impedance of the
antenna. The radio signal should pass through the plastic and hit the metal
antenna element.

Apparently you have missed the interesting discussions with our Polish
friend.

Many thanks for your time Gents, The antennas were intended for outdoor use
and constant handling. being encased in hard plastic obviously enhances
those functions. My experience has been at the other end of the spectrum so
to speak and I (incorrectly) assumed an antenna picks up an electrical
signal. Putting a layer of insulating plastic on it seemed contradictory. If
antenna is detecting magnetic signals obviously a different story.
When I mentioned impedance I mislead you. Wasnt referring to antenna
impedance but the impedance looking back form the recieving antenna to the
signal source ( thats what us old analogue designers do, Norton/Thevenin
equivalent circuits etc !!!!) and the effect on that a layer of plastic
has.
Your combined efforts have answered a lot of my questions, thanks for your
time.
Cheers
John
"Rob" wrote in message
...
Ian wrote:
"John" wrote in message
. au...
My question is how do they work?. If they are detecting electrical
fields
how does increasing source impedance by 100,s of megohms improve
things?.

Pardon? The coating or conduit shouldn't affect the impedance of the
antenna. The radio signal should pass through the plastic and hit the
metal
antenna element.

Apparently you have missed the interesting discussions with our Polish
friend.

I was sort of hoping you might be able to
give us a Make and/or Model number so
we could have a peek at it (assuming we could
find it on the net somewhere)..

Irv VE6BP


"John" wrote in message
. au...
Many thanks for your time Gents, The antennas were intended for outdoor
use and constant handling. being encased in hard plastic obviously
enhances those functions. My experience has been at the other end of the
spectrum so to speak and I (incorrectly) assumed an antenna picks up an
electrical signal. Putting a layer of insulating plastic on it seemed
contradictory. If antenna is detecting magnetic signals obviously a
different story.
When I mentioned impedance I mislead you. Wasnt referring to antenna
impedance but the impedance looking back form the recieving antenna to the
signal source ( thats what us old analogue designers do, Norton/Thevenin
equivalent circuits etc !!!!) and the effect on that a layer of plastic
has.
Your combined efforts have answered a lot of my questions, thanks for your
time.
Cheers
John
"Rob" wrote in message
...
Ian wrote:
"John" wrote in message
. au...
My question is how do they work?. If they are detecting electrical
fields
how does increasing source impedance by 100,s of megohms improve
things?.

Pardon? The coating or conduit shouldn't affect the impedance of the
antenna. The radio signal should pass through the plastic and hit the
metal
antenna element.

Apparently you have missed the interesting discussions with our Polish
friend.

John wrote:
Many thanks for your time Gents, The antennas were intended for outdoor use
and constant handling. being encased in hard plastic obviously enhances
those functions. My experience has been at the other end of the spectrum so
to speak and I (incorrectly) assumed an antenna picks up an electrical
signal. Putting a layer of insulating plastic on it seemed contradictory. If
antenna is detecting magnetic signals obviously a different story.
When I mentioned impedance I mislead you. Wasnt referring to antenna
impedance but the impedance looking back form the recieving antenna to the
signal source ( thats what us old analogue designers do, Norton/Thevenin
equivalent circuits etc !!!!) and the effect on that a layer of plastic
has.
Your combined efforts have answered a lot of my questions, thanks for your
time.

Unfortunately the clueless idiot from Poland has woken up and is
making his outdated claims again...

What you should know is (and apparently have realized by now) that
the antenna impedance is not an impedance between its elements and
the surrounding air, but a "radiation impedance" that results from
the antenna emitting an electromagnetic field. This field traverses
plastic, a vacuum, air etc without problem so it does not matter if
you coat the elements.