[TowerTalk] OT: Inductor Calculator

[terry burge]

Folks,

Perhaps I look at this a bit different than some. But this formula worked a lot better for what I wanted. Calculating the inductance needed for my 130 foot 12 gauge insulated wire fed against my 60+ radials under my hytower. It just seemed more practical from an antenna building stand point.

I am also thinking able my original plan for my 80 meter 4-square when I planed to use 40 foot long 3" irrigation tubing mounted up on 4" X 4" post. The verticals would have needed more length and I thought about both a coil at the base for taping the resonance easily. And a coil at 40 feet up (dual coils) with a stinger. Maybe about 60 feet altogether or so.

My biggest problem with using the verticals was how to raise the 60+ feet of verticals up on those elevated post by myself. Thus I tried using 1/2 WL slopers like K8UR and others and pulled the lower half back towards the base of the tower. Ala four sideways inverted 'V's like. It's working but still needs to be better. But I still kind of wonder about using the quarter wavelength verticals anyway.

But No Running Radials Again and Straining my back. NO! By the way, I saw no difference between the resonance of a straight sloper and one pulled back in on the lower half. Very close to the same frequencies.

Terry
KI7M


> On February 27, 2019 at 7:06 PM john at kk9a.com wrote:
> 
> 
> Perhaps this calculator asks the questions that you are looking for:
> https://m0ukd.com/calculators/loaded-quarter-wave-antenna-inductance-calcula
> tor/
> 
> John KK9A
> 
> 
> terry burge ki7m at comcast.net 
> 
> Hey folks,
> 
> I look at these coil calculators and come to the only conclusion is the
> wrong question is being answered. Example:
> 
> If I have 130 feet of 12 gauge multi-strand insulated house wire (from
> Lowes) how large of 3-4" coil wound on a PVC form do I need to resonate it
> at 1830Khz? 1850Khz? 1880Khz?  1920Khz? 
> 
> Or using a commercial coil from what I believe was an AM broadcast station
> like pictured on my qrz page? (qrz/KI7M)
> 
> Or if you are real ambitious using some small Aluminum tubing from
> DXEngineering or similar source?
> 
> These coil formulas always seem to want some factors that may not be known
> about using the available material like 1/4" or 1/8" copper tubing. Or
> number 8 gage copper I see in the local Lowes or Home Depot. And how to get
> something silver plated once out of high school chemistry class I don't
> know?
> 
> Just a thought or two.
> 
> Terry
> KI7M
> 
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