Herb --

I don't have Beverages, but rather pennant antennas.  I think we have potential 
problems at both ends of the feedline and need protection at both ends.  I use 
Fair-Rite 31-material snap-on cores at both ends, and there's a noticeable 
difference in the noise level if I remove either one.

I suggest you check out "A Ham's Guide to RFI, Ferrites, Baluns, and Audio 
Interfacing," by Jim Brown, K9YC, which can be found at 
http://www.k9yc.com/RFI-Ham.pdf.  I found it very helpful in understanding that 
problem and others, and have been able to do a lot to reduce the amount of 
locally-generated noise that finds its way into the shack.

Hope this helps.

Art Delibert


From: Topband <topband-boun...@contesting.com> on behalf of Herbert Schoenbohm 
Sent: Thursday, December 1, 2016 12:06 PM
To: Topband
Subject: Topband: Beverage Feed-line Noise Pickup

On my Beverage feed-line RG6 runs (some 200 feet) I use multi-turns a
large toroid on each feed-line and the attach each coax to a grounding
block and good ground rods (typical Hume Depot RG-6 variety)  then on
the other side of the grounding block before the coax runs about 20 feet
to the Beverage Switch I have another large wound 13 turn toroid.  I
have since learned that I probably have all my feed-line noise
suppression stuff in the wrong place and that the equipment side toroids
are probably useless anyway.  Now I am told that this noise pickup
suppression stuff needs to be out by the actual Beverage feed and about
20-30 feet away.  The reasoning is that the noise pickup by the
feed-line needs to be blocked from coupling into the antenna itself.  Is
this true?

I am starting to move the toroid-ground-toriod RG-6 "T" combos out
closer to the antennas.  I noticed that DX-Engineering sells an RFCC-1
box designed for Beverage coax runs but suggests it be place about 20 to
30' from the Beverage feed which has it's own separate ground rod.  I
bought one and before I put it out near the Beverage feed I thought I
would it in place of the toroid system near the shack on one of the
Beverage feedlines.  However when I grounded the unit to the Beverage
ground system near the shack I immediately noticed the noise floor jump
up by about 10 db.  I now know it is in the wrong place but this test
with the DXE RFCC-1 may prove something of interest.  Please correct my
assumption if it is wrong:  Noise pickup from long Beverage feed-lines
flows back toward the Beverage feed point and then it is  coupled via
the feed point transformer back down the center conductor to the
receiver.   If this is true I will remove all toroids at the house and
put them out near  Beverage feed points (about 30 feet away with
separate grounds based on the advice I receive back from this post.

Please let me know what you think about this.

Herb Schoenbohm. KV4FZ

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