On Fri, 7 Sep 2012 13:58:38 +0000, ULLS
wrote:


I am trying to receive an am signal well below ground level in a metal
server room, there is a coax feed up to the roof which I used and
attached the standard wire loop that was supplied with the tuner,
however when I attempted to tune into some stations I could only pick up
a couple of local stations and wasn't able to receive the ones I was
hoping for. when I dialed in the desired frequencies, all I was
receiving was a tone, the tone changed in frequency/pitch depending on
the tuners frequency. To check that I could receive the stations I took
the tuner to the roof and attached the antenna directly and sure enough
I could pick up the desired stations. My thoughts are that the coax is
affecting the signal in some way, perhaps picking up electrical noise?
any advise would be appreciated.

Rent a room directly under the roof.


w.

On Fri, 07 Sep 2012 19:35:42 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

Rent a room directly under the roof.
w.

Or, get an outdoor or marine AM/FM receiver and mount it on the roof
in a weatherproof NEMA box.
http://www.ticcorp.com/outdoor_amplifiers_amp10pic.htm
CAT5 should be sufficient to run the audio and DC power down the pipe
to the server cave.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

In message , Jeff Liebermann
writes
On Fri, 07 Sep 2012 19:35:42 +0200, Helmut Wabnig [email protected] ---
-.dotat wrote:

Rent a room directly under the roof.
w.

Or, get an outdoor or marine AM/FM receiver and mount it on the roof
in a weatherproof NEMA box.
http://www.ticcorp.com/outdoor_amplifiers_amp10pic.htm
CAT5 should be sufficient to run the audio and DC power down the pipe
to the server cave.

I think a Google on 'active antenna' might give you a lot more general
information. Start he
http://en.wikipedia.org/wiki/Active_antenna

They typically untuned (and hence fairly wideband).

An active antenna often consists of a short whip antenna, which
functions as a high-impedance RF voltage probe. This is connected to the
input of an amplifier which has a very high input impedance. The
amplifier provides gain, and also converts the high impedance of the
whip to a low impedance, which is suitable for connecting to 50 or 75
ohm coax feeder.

Of course, the amplifier has to be powered, and typically this is
provided by a DC power unit located at the receiver end, which sends the
necessary power back up the coax.

Note that one thing an active antenna must do is not to be overloaded by
strong signals (which can be a problem if you have a local transmitter
or two in your area).

But as I say, have a Google, and see what information it brings you.
--
Ian