View Single Post
  #10   Report Post  
Old January 6th 07, 11:55 PM posted to rec.radio.amateur.homebrew
Ceriel Nosforit Ceriel Nosforit is offline
external usenet poster
 
First recorded activity by RadioBanter: Sep 2006
Posts: 14
Default Making vari-caps for ATU

Alas, on the wretched hour of Fri, 05 Jan 2007 23:52:01 +0100 Highland
Ham thusly proclaimed:

How is your tuner going to be semi-automatic, if I may ask?

=========================
Suggest you consider a stepper motor from a dumped
printer/scanner/floppy drive or HD ,if necessary including a shaft
rotational reducer when steps are too big.
Google will provide you with suitable (simple) circuits to drive the
motor ,usually involving one or more opamps.
From semi-automatic the circuit can evolve towards a fully automatic
system with a SWR sensing circuit.

Frank KN6WH/GM0CSZ


You know... I just happen to have two old floppy drives in my drawer.
Might be able to control them as they are through the standard cable if I
have the right software. Would just have to make another mechanical
modification to put the motion to use. A standard diskette might come in
handy for that.

Excellent idea! Thanks!

--
Nos