[TowerTalk] F12 C3E adventure

[K7LXC@aol.com]

Greetings, TowerTalkians --

       Here's some info from Glenn, K3SWZ:

>> Subject:  Force 12  C3E report

I finally got the Force 12 C3E up that I purchased last September.  My
fooling around last fall permited me to buy the 10 reflector kit (the
"E") that was offered this spring.  The antenna went together real
well... Only one rivet to drill out and that was caused by "cockpit
trouble", not Force 12.   I was concerend about the SWR on 10 and 15
meters,  After following all of the posts on TT and talking to the
factory, I went with the 20 meter settings per the book.  On 10 and 15
meters I left 2 rivet holes showing on the driver elements.  I haven't
done any extensive SWR plots yet but it looks fine in preliminary
testing.   Now for the details....  Thanks to NE3H, K3WC and K3LHD who
did the climbing at various stages..  We managed to drop the Mosley
TA-34 that was on the way down!  It suffered no damage from about 15
feet and is going on the short tower for a multipler antenna..... When
the C3E was first tested it was terrible!  >3:1 SWR everywhere on all
bands!  I was sick....  Through some testing and checking we found that
the N to SO-239 adapter on the tower had gone bad?  It connected my 9913
run up the tower to a 9913 flexi jumper. Why, who knows. Things got
better but still very poor.....  I then started in the shack by taking
everthing out of the system and running the 9913 directly into the
TS-850S/AT.  Bingo, it was perfect!  Now something  was sick in the
shack.  Why?  Turned out to be a 2 foot  RG-8 jumber that has been in
use in the same position for years....  Bad!  It appears upon
examination, that it got pinched with too tight of a radius, but why
now?  It hadn't been touched.  Anyway, replaced it and
the match looked great! Lesson: Don't assume anything! I couldn't
beleive what I was seeing.  This project almost caused me to take up
stamp collecting!
I did make two modifications to the C3E.  I was not happy with mounting
the Force 12 balun with tape and cable ties to the boom.  I went to the
local electrial supply house with my calipers and the boom and balun
diameter measurments.  I bought metal conduit clamps of the right sizes
(two of each) and bolted them "back to back".  The balun is now very
strongly attached to the boom...  Yes, they will rust eventually, but I
shot them with some paint first..  I was also concerned about the effect
of UV on the gray PVC insullators.  I took the insullators off of the
elements so I could paint them.   I bought a can of Krylon white spray
paint and blasted the entire can on the insullators in light coats and
allowing them  to dry between coats.
This should increase the resistance to UV..
Also got a CC 40 meter rotary dipole on top of the mast which seems to
be great.
Also added a 3 element Telrex 10 meter monobander at 40 feet fixed on
South America...  I am interested to see how that plays...  Telrex
really knew how to build antennas!  Also took the opputrtunity to swap
out the T2X rotor with a Norms Rotor Service rebuild while everything
was apart.  My T2X had a stricky brake anyway....
I am looking forward to this Fall and Winter to see how things go....
73
de Glenn Kurzenknabe, K3SWZ
bgkurz@epix.net  >>

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