On Jan 18, 2:05*pm, bpnjensen wrote:
On Jan 18, 10:57*am, John Smith wrote:



On 1/18/2011 10:44 AM, bpnjensen wrote:

...
Actually, no, and I am sorry if there was a misunderstanding - I meant
an inline (in the coax) RFI reduction system.

Baluns/ununs really are NOT an RFI reduction system. *They provide
proper impedance matching between antenna and feedline. *Coax, with an
rf choke (can be a balun/unun) allows the feedline to run though noisy
areas and not pick up the noise there, such as when it enters a house
with noise present.

Baluns/ununs/rf-transformers, because of the use in gaining a superior
match (transfer of signal energy) improves signal to noise ratio, in
most instances, and this can appear to be functioning as a "RFI
reduction system."

Some useful links:http://users.belgacom.net/hamradio/s...ongwire%20Balu...

Regards,
JS

OK, understood, but I have always thought (based on what I have read)
that one of these matching transformers, properly deisgned and
grounded, can bleed off some noise to ground. *Am I misled?

The 'concept' is that the Feed-in-Line "Inline Isolator"
[1:1 Transformer] is in the Radio Shack -or- at the point
the Feed-in-Line enters the House/Building.

Mount the "Inline Isolator" directly on a Ground Rod
right outside the Radio Shack Window.
http://www.wellbrook.uk.com/longwire.html

Placement at this point prevents the AC Line Noise
and other RFI Noises in the House from 'migrating' out
along the Coax to the Antenna|End; and then ?reflecting?
back from the Antenna along the Coax back into the
Radio Shack and into the Radio/Receiver.

iane ~ RHF