Many thanks everyone. I'm spoilt for choice.
John F5VLF
On 6 Jul 2011, at 20:06CEST, Rick Jenkins wrote:
> Hi John,
>
> On Wednesday, July 06, 2011 11:21:35 AM you wrote:
>> I am experimenting with various forms of matching network to go between my
>> 136kHz antenna and the transmitter. It would be very handy if I had a
>> fairly simple circuit analysis program with which to do the following:
>>
>> Having measured the input impedance to the combined matching unit and
>> antenna, then “subtract” the components of the matching network, see what
>> I get and compare it with what I actually measure. I'm not always
>> convinced that what I measure is what I think I'm measuring.
>>
>> Platforms available: XP, Linux and MacOs X.
>>
>> Yes, I could write something, but somebody must have done this and there is
>> no point in reinventing the wheel.
>>
>> Any suggestions, please?
>
> Faced with the need to do math, I usually turn to Maxima. This is a
> descendant
> of the original DOD Macsyma, now with an open-source license. I run it on
> Linux, but I am told the W*ndows version is good too.
>
> With a little fiddling I can usually carry through a symbolic s-plane
> analysis
> of a network with not too much trouble, then substitute s=jw, then throw in
> numerical values and plot the results. There is a visual interface called
> wxmaxima, and plotting is best done via gnuplot.
>
> It takes a while to do your first analysis, but as you use the system you
> slowly come to understand its philosophy, and life gets faster and slicker. I
> find this *much* more accurate than fiddling about with pencil and paper.
> Maxima
> never drops a sign or a 2*pi.
>
> Hope this helps,
> --
> Rick Jenkins <[email protected]>
> Hartman Technica http://www.hartmantech.com
> Phone +1 (403) 230-1987
> 221 35 Avenue. N.E., Calgary, Alberta, Canada T2E 2K5
>
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