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Old January 11th 07, 08:06 AM posted to rec.radio.amateur.antenna
Rich McAllister K6RFM Rich McAllister K6RFM is offline
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First recorded activity by RadioBanter: Jan 2007
Posts: 10
Default Choke balun

Richard Clark wrote:
On Tue, 09 Jan 2007 23:47:41 -0800, Rich McAllister K6RFM
wrote:

So, does anybody here have any idea
why the coax coil choke and the ferrite bead choke would have been so
different?


Hi Rich,

I have been using a GAP Eagle for years, and it resonates in every
band as advertised (which is not to be mistaken for works miracles in
every band).


Sure, any small antenna like this is going to be a compromise. I was
actually pleasantly surprised by the performance on 40M during the RTTY
Roundup last weekend, I expected the Eagle to pretty much suck wind
compared to my old full-size dipole, but it compared very favorably.


It comes with its own ferrite choke (aka 1:1 BalUn) on the pigtail
lead coming out of the bottom. Over the years and with wind, that has
chipped and broken, but replacing it returned the original
performance.


I've got the GAP-supplied ferrite choke protected with heatshrink
tubing, and the whole thing secured pretty well to the mast, so I'm
hoping not much will flop around and it will last a good long time.

By the way, I did have it elevated 10 feet up - this
makes a difference.


I've got it at the same spot as my old Cushcraft R5, a 10-foot mast on
the porch roof secured to the main roof rafters so the mast sticks up
about 3 feet over the main roof, the base of the Eagle ending up about
30 feet in the air. This basically is the only spot I have which is
both reasonably accessible in case I need to fiddle with the connections
and a good distance (at least 20 feet) away from major metal like
power/phone lines, etc. It's also just about the midpoint of my lot so
I keep the radiation as far away from my neighbors as possible;I figure
that has to help with RFI and also helps me do the radiation-exposure
self-evaluation with a clearer conscience.

Rich, K6RFM