Bill Coleman N2BC wrote:
>The 30S-1 L101 is a silver plated inductor.
No nichrome there, then...
>I believe it is used to lower
>the effective plate load resistance to allow a reasonable tank Q at higher
>frequencies. I did this with a 5CX1500 RF generator (13.56mHz) which I
>converted to the ham bands, worked out very well.
>
In effect, this taps C1 of the pi tank part-way along the inductor, so
that Cmin doesn't add so much to the total input capacitance. On the
other hand, it makes the design calculations more complicated.
>Used your NETCALC
>program a LOT - made things easy!
Now that we have computers, this approach probably deserves more
attention.
NETCALC is a BASIC program that I wrote about 20 years ago as a 'pocket
calculator' for complex impedances. It automates operations like
series/parallel transformations, and adding series or parallel
impedances, reducing them to single-keystroke operations.
The DOS user interface is so last century, but it does the job. One of
these years, I'll rewrite it for Windows...
>My implementation is here: http://home.stny.rr.com/n2bc/PT_Project.htm a
>page I put together for our club members.
>
Very nice!
>THX for NETCALC!
I still use NETCALC for small jobs, but for tank design and analysis I
now tend to use a spreadsheet. Both are on the web site.
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek
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