This is mainly for newcommers to the SWL hobby

This article formsthe basies of my present SW/HF antenna ground setup.
http://members.aol.com/WA1ION/nrants.pdf#search='NRANTS%20pdf

This is a simple easy to build 9:1 matching transformer.
Please read the rolling your own spliter for soem valid observatios on
larger vs small torroids. And John doty's comments on using the feritte

"binoculars" from the common TV 300:75 ohm matching tranformer for a
really cheap 9:1 makes a lot of sense.
http://www.hard-core-dx.com/nordicdx.../9_1balun.html

John Doty's ground system. I used this for several years before
upgrading to the WA1ION system. A very good system that may not
be worth the trouble to improve upon. I had switched to a braid/foil
coax and found I still had some birdies from my PC. Isolating the
grounds removed the last audible trace of my PC clocks.
http://www.anarc.org/naswa/badx/antennas/grounding.html

John Doty made some measurements and shows why a 9:1 matching
tranformer
can help the average antenna receier combo.
http://www.anarc.org/naswa/badx/ante..._longwire.html

John Doty's low noise antenna design some pratical and workable antenna
feedline sugestions.
http://www.anarc.org/naswa/badx/ante...e_antenna.html

John Doty had a chance to play with a decent radio in a very quite
RF location. His comments are interesting and I found them usefull.
At the very least it is nice to know that not everyplace is an RF
wasteland.
http://www.dobe.com/wts/funk/islandexp_JD.html

I posted this one before, but even for those who don't wish to use
an antenna splitter there is some usefull information. The comments
on torroid size and the effects of the measured mismatch to actual
receiver performance were especially illustrative. From my own
experience in winding 9:1, and other ratio, transformers I found teh
smaller feritte cores worked much better. Teh common TV matching
binocular is hard to beat in terms of performance and availability.
http://www.dxing.info/equipment/roll...own_bryant.pdf

There has been and continues to be an ongoing debate over the merits
of 50 Ohm coax vs 75 Ohm coax. I have used both and for LF/MW/HF
receiving could measure no difference in the RF at the receiver.
The Z of the cable had no effect on how well the radios received.
This was with a variety of receivers ranging from a R390, R392,
R5000, R2000 and a Lowe 150. A complete list would be long and
tedious.

What I found to be be much more important then the Z of the coax was
the amount of shielding. Most braid only coax only has ~95% shielding.
I found the 5% leakage allowed noise from my other radio room
equipment,
PC monitor etc, to enter the coax and added a lot of noise. By going to

braid and foil coax I reduced the crud from my PC to negliable, ie
below
the threashold of reception, levels. I can run audio FFT programs and
still find my PC, video board and other clock freqs, but for normal day

to day listening they are just gone. John's comments on burrying the
coax make sense and I decided to go a little better. I have collected
a fair number of feritte RFI control beads over the years. I placed
one about every 6~8" for the entire length of the cable. I cann't give
any real numbers, but I am certain this helped reduce the common mode
leakage on the coax.

A similar but easier can be found at:
http://www.arising.com.au/people/Hol...ph/CMBalun.htm
Almost everyone has a dead AM radio kicking around and this a perfect
use for the feritte rod. I have used similar configurations and found
them to be nearly as effective as feritte beads or torroids.

While this is common sense, it bears repeating:The lower your noise
floor, and the lower the man made noise your antenna brings to your
receiver the weaker signal you can receive. Since few of us can move
to RF quite zones, the only practical action is to improve our antennas

and grounds as much as practical. REducing the noise picked up by the
antenna and ground can improve a system enough to make you think you
just got a new and much better receiver.

I am experimenting with the AMRAD LF active antenna and have found that

it is very good antenna, and approaches a good long wire most of the
time.
At LF and VLF it is much quiter then my longwire. I still had to
decouple
the coax to keep noise from radiating back through the shield and
entering
the antenna. For the AMRAD a bunch of feritte beads or common mode
choke
is a must have.

Terry