Kirk
The short answer is how tight you make the turns will have little real
world effect. Use the RG-8X I would probably use the #31 core over the
43 . The poor mans 8 turns of coax 4-5" in diameter without ferrites
will probably actually work as well. Depending on SWR and feed line
dressing (always perpendicular to the plane of the beam the need for
choke at all� is arguable .
Dont forget you guys up north get several dB of extra gain for erecting
antennas in subzero weather and another 1dB bonus if done during a blizzard.
Dave
NR1DX
On 11/6/2020 2:39 PM, Kirk Kleinschmidt via TowerTalk wrote:
Hi, gang,
I'm racing the arrival on Minnesota's winter, and I need to install a
hexagonal beam on top of my short test tower.
In the past, when building RF chokes onto FT-240-43 or FT-240-31
ferrite cores, I wrap the turns tightly around the core. With my RG-8X
rotator loop, I'm not sure that I should wrap them so tightly?
The G3??? Hex Beam SK from karinya.net tested a bunch of RF chokes,
and one of his recipes that should work for a 20-10 antenna is 5 turns
of RG-58 around an above-mentioned Type 43 core.
Question: Do I have to wrap the turns tightly (risking center
conductor migration?), or can I loop the 5 turns through the core with
a 2-inch bending radius?
If that makes a difference, should I add additional 2-inch-radius
loops? I tested and can get as many as 10 turns through the core.
NOTE: I do not have time to purchase different cores, cables, etc.
Winter is 48 hours away. :)
I have suitable lengths of RG-58, RG-8X, RG-213 (don't wanna cut it
tho), LMR-240, RG-6 quad, LMR-400 clone (can get from a fellow ham) on
hand to make this rotator loop/choke. I have FT-240-43 and FT-240-31
cores on hand,
Thanks, as always,
Kirk, NT0Z
My book, "Stealth Amateur Radio," is now available from
www.stealthamateur.com and on the Amazon Kindle (soon)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
--
Dave Manuals@ArtekManuals.com www.ArtekManuals.com
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|