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1.2ghz uplink AMPLIFIER



Hi, all:
        Since I've seen my name pop up here and there ("Mode S:The Book";
still an excellent reference on UHF, including antennas, practical info,
what to expect, etc., 120 pages for $15 from AMSAT. A useful deal. Call
Martha.), I thought I'd throw in my 2 cents concerning L band uplink (which
I have been doing since AO10)
        It's not magic. Buy a transmit converter from Down East Microwave
or SSB USA. Or a kit from DEMI. Or build W1BFN's DC transmitter. Then
homebrew an antenna and amplifier, which is the point of my note.
        Try this reference: 1998-2001 ARRL Handbooks. See my article
entitled "An Integrated L-Band Satellite Antenna and Amplifier". It details
a 15-turn helix (or build whatever length you want from Fred Spinner
W0FMS's neat javascript helix designer program) and a tower-mounted 10-15
watt brick amplifer that is so easy to build and foolproof it will knock
you out. The "integrated" reference in the article is that I suggest
mounting the amplifer on the back end of the helix antenna as a
counterweight, and using the coax back to the shack as an attenuator. It
also has a method of holding the helix at DC ground, making it much more
resistant to being killed by static.
        No, I don't have copies of the article. Support the ARRL. But I do
have drawings that show all about how to build the amplifer itself.
Schematic, board, layout, parts, etc.. If anyone is interested, write to me
and I will email them to you, zipped together.
        As a side comment, thanks a ton to the command station guys! 

73,
Ed Krome K9EK
k9ek@amsat.org
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