Hi Steve
If you could find some old ARRL handbooks from back in the 40's, there is
lots of information there about link coupling antenna tuners. Most of the
transmitters back then used link coupling in the finals. 73
Tom W7WHY
> Hi Rick,
>
> Thanks for the info, I thought the methodology existed but didn't
> immediately find it. Appreciate the offer to scan and send but I don't
> think it will be necessary.
>
> Jim Lux, in an off-reflector note, steered me to a program named Inca at
> http://www.coe.ufrj.br/~acmq/programs/. It appears that this will meet
> my needs.
>
> I'm working on a link-coupled antenna tuner for 160 meters and was
> curious about the coefficient of coupling for the inductive link. Inca
> indicates the coefficient for my pair of coils is 0.51.
>
> Thanks again and 73,
>
> Steve K8JQ
>
> Rick Karlquist wrote:
>> Steve wrote:
>>
>>>Just wondering if there's a way to determine coefficient of coupling
>>>based on the physical dimensions of the two coils and their mounting
>>>with respect to each other?
>>
>>
>> Of course, F. W. Grover figured this out a century ago.
>>
>> Grover, "Formulas and tables for the calculation
>> of mutual and self inductance", NBS Paper 169, 1912.
>> (NBS is now NIST)
>>
>> Grover, "Tables for the Calculation of the
>> mutual inductance of any two coaxial single
>> layer coils", Proceedings of the IRE,
>> July 1933 pp 1039-1049. (IRE is now IEEE).
>> This paper claims to have easier to calculate
>> formulas. Of course that was precomputer. Not
>> clear which would be easier now.
>>
>> I have the latter paper in my personal library. I can
>> scan it in if you can't find it at your local engineering college.
>> I also have the NBS book, but it is fairly lengthy to scan in.
>>
>>
>>>Didn't find it in the Handbook, nor did a google search turn up anything.
>>
>>
>> Google on "grover" and "inductance" and you'll get a bunch of hits.
>>
>>>Steve K8JQ
>>
>>
>> I can tell you ahead of time that it is difficult to get coupling
>> above 50% and impossible above 80% or so.
>>
>> Rick N6RK
>>
>>
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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