[TowerTalk] Choke-Winding Wire Effects?

Kirk Kleinschmidt sohosources at yahoo.com
Fri Dec 11 04:10:50 EST 2020

Hi, Jim and the group,
I need to wind a low-band feed point choke on one or two FT-240-31 ferrite cores, and I noticed that various wire and coax chokes (measured) are listed in the cookbook.
1. The black and white wires from 12-gauge "romex" are listed, but I have on hand lots of black and wires wires from 12-gauge, heavy-duty extension cords. This is stranded, which I understand isn't as well behaved as solid, but I'm wondering whether the choke performance is similar to same-sized romex? I'm guessing that it is.
2. If I decide to use two cores in series, do I have to connect them "end to end" (like the wheels on a car), or can I stack them with some minimal spacing (like stacked dinner plates)?
This is a 10-100 W choke, so dissipation isn't likely to be a problem. I have RG-58 on hand, but I don't see any current winding data for it and I want to make a choke that "has data" instead of just guessing. This choke will be at the base of an inverted-L and will be in a waterproof box, so WX shouldn't be an issue.
As always, thanks,
--Kirk, NT0Z

My book, "Stealth Amateur Radio," is now available from www.stealthamateur.com and on the Amazon Kindle (soon)

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