I've no source for premade but several links that might help you roll your own.
I used AD5X's technique to make loading coils for a shortened 40/15M dipole I
use on my sailboat. The elements are supported on two Jackite telescoping
fiberglass poles joined end-to-end in the middle. While the poles would easily
support a full sized 40M antenna I don't have the room due to other vessel
masts on either side along the dock. Happy to send you a picture of a coils I
made if you want. Note that I used his method of spacing the windings but
didn't need the support structure he describes for his vertical application.
AD5X's article is here: http://www.ad5x.com/images/Articles/CoilRevB.pdf
There is another one that may be of interest here:
"Homebrew Your Own Inductors," by Robert H. Johns, W3JIP, QST, Aug 1997, p 35
I used W8WWV's method for winding a single large coil for my 80' high 160M
vertical over saltwater. I used 1/8" refrigeration tubing for that one.
His article is here:
http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/HiQCoil.htm
K7MEM has some nice on-line calculators that might be helpful here:
http://www.k7mem.com/Site_Map.html#HF%20Wire
Patrick, W7TMT
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Frank VO1HP
Sent: Monday, March 15, 2021 16:50
To: towertalk@contesting.com
Subject: [TowerTalk] 40M Loading Coils
Does anyone know of a source of High Q 40M load coils and one could use for a
DIY Rotary Dipole?
73
Frank VO1HP
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