RadioBanter - Low Noise Receiving antennas

pa3abk wrote:

On Fri, 12 Oct 2007 20:03:08 -1000, Tony Giacometti
wrote:

JIMMIE wrote:

On Oct 11, 1:38 pm, Tony Giacometti wrote:
I live in a neighborhood that as the years have gone on
has added a number of new homes. This has increased the
electrical "noise" for me where S1 or S2 on 80 meters 6-8 yrs ago
is now S7 to S9. At this point in time I don't have the room for a
K9AY setup. I can only "dream" of a beverage.

I have a Timewave ANC-4 which works very well on 40 meters as I can
null out ALL the "noise".

Not so on 80 meters as it only knocks it down 2 S Units.
At best I have an S-6 noise level.

This leads me to believe that I need a separate sensing antenna for 80
meters. Anyone have any ideas for this problem? Is this thinking
correct?

I have been looking at low noise receiving loops and other low noise
antennas. Wellbrook athttp://www.wellbrook.uk.com/seems to have some
interresting possibilities, but some of the reviews I have read have
made me hesistant to purchase any of their products.

What I need is some serious input from anyone who has any experience
and knowledge in dealing with low band noise issues.
As I am now space limited due to all the new neighbors any solution
would need to take this into consideration.

TIA

Just out of curiosity, have you tried locating the noise source. I had
the same experience you are having more or less.
I had been away from ham radio for a couple of years and when I fired
it all up again HF was really noisy so I ran the radio off of battery
while I shut down power to my house. I found the source of the noise
was the display on my microwave oven.
Short term solution was keeping the microwave unplugged until needed.
Long term solution was replacing the microwave. I did this when i
found a better one at Goodwill for less than $20. Also check for RF on
the coax during transmit. During rx this means the antenna is also
picking up signals from the shield which may be in close proximity to
noise generators.

Jimmie

I did a good assessment of the noise being heard here.
I found an electric razor charger that was some of the problem and
a computer printer was another I found.
So my home is quite clean unless something else has popped up which I
don't know about and can't locate.

I test with power on and power off. Right now theres very little
difference if any between the two.

I would think its coming from someplace else, but until I can come up with
the exact location I need to decide on a solution thats effective.
Understand your problem. In the Netherlands we live rather dense to
each other. Consequently when you are a ham and try to receive
something you are confronted with a blanket of man-made noise from
various sources. Mainly they are coming from switched power supplies
in some kind. It's almost impossible to adress all neighbours and
de-noise the equipment. In NL the responsible salesman should remove
these kind of QRM, you will imagine that it will cost a lot of effort
convince him that his product is causing the problem. To get around,
you can sample the noise, reverse it and add it to your antenna
signal. The QRM is simply nulled out. The earlier mentioned ANC-4 is
doing that, however I understood it's not capable to to do the job
very well. Same goes for the MFJ-1025.
Have a look at the page of pa0sim
http://www.pa0sim.nl/Phaser%2080%20-%2010%20meters.htm
Don't worry it's in English and it gives you some ideas how you can
tackle the noise/qrm problem.
If have your QRM sensor is correctly placed for picking up the "noise"
and feedback it, it should do the trick. Alternatively, for those who
have not the man made noise problem, you can null-out a short skip
station in favour of that DX station you would like to work.
Jan/pa3abk

thanks for the info, I will study it carefully.