Transformer for longwire antennas to reduce noise problem?
 

Dorm room, noise hell, lighting fixtures, computers, digital devices, wall
warts, power lines, distribution lines, transformers for building
equipment, radios, tvs, etc. all conspire to make radio reception a bit
dicy fro all the rfi produced. The wire just makes reception of all those
nearby sources all the better. Try grounding to a known ground, a
transformer is not likely to help, it doesn't distinguish all the noise
sources from other signals. Get battery power and pull the main breaker
for the building.

Hey -

I posted in here recently about active shortwave antennas - well, I
managed to get 75 feet of #26 magnet wire on a perpendicular roof to
my window of my dorm room, and two runs of 15' speaker wire as a
counterpoise in my room. I'm getting a really bad noise problem,
however - so bad that I can't hear stations on 20 meters! There's a
pretty solid S9 noise floor that prevents me from hearing anything
other than WWV and the major broadcast stations. Now, I know I can do
better with the amount of wire I've got strung out there.

I was thinking about adding one of those 9:1 transformers or other
impedance matching things for longwires; would this reduce the noise
problem I'm having? Any other tips for reducing longwire noise? It
works enough, but I know I can do better...


Thanks in advance.

Hmm, this seems to go against all the advice I've gotten so far, about
getting as much of the antenna outside as possible...I find it hard to
believe that an active antenna is going to get better reception than a
75' wire, but if it does, than it does...

On 27 Sep 2004 15:40:25 -0700, (TheGnome)
wrote:
Hmm, this seems to go against all the advice I've gotten so far, about
getting as much of the antenna outside as possible...I find it hard to
believe that an active antenna is going to get better reception than a
75' wire, but if it does, than it does...

Hi OM,

Not sure what you are responding to, but the implication you offer of
an active antenna surviving in a field of noise better than a remote
antenna is a sure cause of wonderment.

73's
Richard Clark, KB7QHC

In article ,
(TheGnome) wrote:

Hmm, this seems to go against all the advice I've gotten so far, about
getting as much of the antenna outside as possible...I find it hard to
believe that an active antenna is going to get better reception than a
75' wire, but if it does, than it does...

Please don't cross post.

A small (shielded) active loop will pick up less local noise than the
other type of antenna unless you can get the other antenna farther away
from all the local noise sources. If you can do that, then the other
gentlemen's advice applies.

--
Telamon
Ventura, California

Richard Clark wrote in message . ..
On 27 Sep 2004 15:40:25 -0700, (TheGnome)
wrote:
Hmm, this seems to go against all the advice I've gotten so far, about
getting as much of the antenna outside as possible...I find it hard to
believe that an active antenna is going to get better reception than a
75' wire, but if it does, than it does...

Hi OM,

Not sure what you are responding to, but the implication you offer of
an active antenna surviving in a field of noise better than a remote
antenna is a sure cause of wonderment.

73's
Richard Clark, KB7QHC

A small active antenna can SOMETIMES really help in a nasty QRM situation.
By trying the antenna in mulitple locations, one can SOMETIMES find
a quit spot. Active antennas are near the bottom of my want list.
But, when I worked at the University of Kentucky, I was able to find a
fairly quit spot so we could receive WWV. It took several tries, but the
results were well worth the effort. We had a ESE WWV controlled master
clock. I would sometimes snag the antenna to to some SWL when I worked
at night. Loops and "long" wires, even dipoles cut for 10/15MHz were useless
because of all the class A digital noise makers in the studio equipment,
and the 2 PC labs that were close.
Terry