[TowerTalk] 40M Loading Coils

[Robert Harmon]

Patrick,

Thanks for sharing this info on making our own loading coils.   I am gathering the supplies to make an 80M vertical dipole to be strung off the side of my tower from a yard arm at 80 feet.
I will put a loading coil in each dipole segment.  I don't want to fool with radials so hoping the vertical dipole will perform OK for DX.  This info is just what the doctor ordered !   thanks !


Bob
K6UJ




> On Mar 15, 2021, at 5:33 PM, W7TMT - Patrick <W7TMT at outlook.com> wrote:
> 
> 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 at contesting.com> On Behalf Of Frank VO1HP
> Sent: Monday, March 15, 2021 16:50
> To: towertalk at 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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