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Old June 17th 05, 06:18 PM
Anders Henriksen
 
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"Lucky" skrev i en meddelelse
...

I live on the 23rd floor of a building so I can't use the earth directly

for
the ground.
The options in my "radio room" are the ground from the electrical sockets
and that's about it.


The ground in your electrical socket is by no means ground radio wise.

I've heard I can roll out 10ft of tin foil on the floor as a ground

{that's
out}, or, use the window frames as a good ground. As far as I can tell,

the
window frame looks to be aluminum or some sort of alloy.


Your ground can either be a real low impedance connection to the soil, or
just a counterweight to your antenna, whitch is basically the same. Not many
people are aware what it actually takes to construct a real RF, and not
safety, ground.

Have any of you heard of using a window frame as a ground? I think I read

it
in this NG that someone recommended it and was using it for his ground.

I've
been using the ground from an electrical outlet.


You can use anything as long as it is metal. The more the better. But you
should use heavy gauge wire for the connection, as short as possible,
otherwise the effect be be lost in the impedance of the cabling.

But being that so many people live in the building that use appliances and
other plugged in items all day and night, I sometimes get what seems like
bad feedback affecting the receiver.


Yeah, I really think you should let mains ground be mains ground and use
something else for RF ground.

So what do you think of the window frame for the ground then? I welcome

any
other options I can use in a room very far from a direct earth ground. The
bathroom pipes are all the way across the room separated by a wall. Not

easy
to get to.


If you have carpet on your radio room floor (in order to hide the tin foil),
you really should consider laying out tin foil, as much and as long as
possible and connect it to the radio/antenna system. The connection between
the tin foil and the radio should be no longer than 6'. You may also lay out
cables around the perimeter of your room, maybe even around the entire
apartment, if you have the possibility.

Consider wether your antenna system actually requires grounding or a
counterweight. Remember that any counterweight or artificial ground will
function as an antenna and possibly pick up noise.

There is actually only one thing to do: Find some theory and then axperiment
to find out what is best at your location.

Best regards
Anders Henriksen, oz7ahr
Denmark