[TowerTalk] RE: [Force 12 Talk] Balun comments by Steve Morris K7LXC

[Avila, Edward]

Since considering, then purchasing a C3 two years ago, every time I called
the Force 12 factory about a product question I got the owner himself on the
phone who always answered my questions/concerns without hesitation or
attitude. Now, can you imagine me getting Hygain, Cushcraft or MFJ's CEO on
the phone to answer questions from bonehead hams like me? I think not!!!

Force 12 service to its customers, i.e.: me, has been outstanding.....and,
never even met any of the Force 12 guys!

73...../k6sdw 



-----Original Message-----
From: force12e [mailto:force12e@lightlink.com]
Sent: Wednesday, September 13, 2000 9:02 AM
To: Force12Talk; towertalk@contesting.com
Subject: [Force 12 Talk] Balun comments by Steve Morris K7LXC 


Regarding Mr. Morris' most recent comments on the Tower Talk Reflector
and/or the FORCE12Talk reflector -

Regarding his comment, "Too bad Tom never reads this stuff."
I obviously do read "this stuff".

There are other avenues of communications besides his
Tower Talk reflector. Anyone with a question or comment on the Force 12
product line has
an 800 line, the FAX number has always been available, our E-mail support is
still active,  the US Mail is available, there
is now the Force 12 Reflector and I am available at conventions and club
meetings. I
believe that going to the appropriate source is the most effective and
proper route.
After all, if you have a question or comment that you want to have answered
about your
Jeep Cherokee, do you go to a GMC reflector?

Regarding the integrity of the standard 3KW B-1 baluns (same construction on
the larger
B-1/C, but the B-1/5KW is a toroid design in a sealed box):
This has been addressed several times before on a reflector, as well as in
person and
even last week in an e-mail to a customer. A balun (regardless of who makes
it) is not
part of the boom structure; therefore, it is not necessary to apply
excessive pressure
during mounting so that the body of the balun is broken. I initially secure
the balun
using good quality tape around the coax and the boom, about 3 inches from
the connector
end of the balun, leaving a slight amount of slack in the balun leads. The
balun can
then be secured to the boom with minimal pressure using tape or tie-wraps
(remember to
cut the tie-wrap close, or trim the corners to avoid the possibility of
cutting
yourself). The core of the B-1 balun is solid epoxy around the Teflon coax
and is placed
in a vacuum chamber during construction. There are no voids. We have
received a few back
from antennas loaned to DXpeditions where they had been dropped onto rocks,
or other
hard surfaces and the PVC was cracked. In a couple instances, the inner
epoxy core was
also cracked (40' drop). They remain fully functional to this day. We
wrapped some tape
around the body for a little rigidity and they are often in use for various
antennas. On
our contest team (e.g. 6Y2A), we use the same baluns, as well as pigtails,
which is the
basic balun design sans the epoxy, PVC and with only a few, long beads. We
toss them in
the pool afterwards, which gives us a reason to finish take-down and cool
off,
retrieving them from the bottom of the pool.

Related issue is why to use a balun? I often use RF chokes, but always use
some device
between the unbalanced coax feedline and the balanced dipole (singe dipole
element or
the feedpoint of a Yagi). The balun (B-1) is weather proof, so I prefer it
over having
to seal the split end of the RF choke; besides, the balun is physically much
smaller on
the low bands.

Trivia question: What's the biggest bead balun we've ever made? Maybe I'll
bring it
along to the next club presentation for an item of interest. The coax in the
balun is
custom built. The outer conductor is 1" copper tube, 18" long. The center
conductor is
1/4" copper tube with a solid aluminum rod insert. The center conductor is
suspended
(air dielectric) with machined rings of some type of plastic material (don't
recall the
type). One end has an N connector using a tapered copper fitting and there
are two #10
leads on the other end. The beads are 2 1/4" OD (1 1/4" hole) and the beads
can be
changed in number and type. The maximum beads the body can hold is 30. With
20 beads, it
weighs 7 pounds - just the ticket for an antenna on one of those excellent
K-2 QRP rigs!

73, Tom, N6BT
Force 12, Inc.











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