View Single Post
  #14   Report Post  
Old November 15th 08, 07:10 PM posted to rec.radio.amateur.homebrew
Tim Wescott Tim Wescott is offline
external usenet poster
 
First recorded activity by RadioBanter: Jul 2006
Posts: 202
Default Homebrew breadboard xmtr

exray wrote:
Hi,
I've gotten far enough along with this project to where I'm ready to
toss it out for public scrutiny, so have at me, guys.

I'm a receiver guy - never built a tube transmitter from scratch and
this is my first go. My goals were, in no particular order, to build
something with a early 30s breadboard look, xtal control, 40/20 meters
primarily - 80/30 as bonus, moderate power for getting on the air
barefoot while not overpowering a future amp idea...and of course using
accessible parts.

This is sort of my compilation of ideas from old QST articles. Robbed
ideas from this and that to make them fit. I made some major boo-boos
at first but I think I finally have them sorted out. Something that
dawned on me a little bit slowly is that none of those old xmtrs were
set up to operate 40 meters with a 7 Mc xtal. Much of the emphasis was
on double this/double that. Nowadays we have 7 and 14 Mc fundamental
xtals abounding so I went the route of reinventing the wheel so to speak.

The rig is working at this stage...at least straight thru on 40. Waiting
for some other bits and bobs to carry on to other bands. The note
sounds good and its nothing I'm reluctant to put on the air. On the
other hand its a massive amount of wood and metal for a measly 5 or 6
watts A little slatboard 6V6 chirper would have been much easier.

Anyway, I'm not a veteran with old xmtrs so I'm putting it out for
comments, questions, critiques, etc. Flame suit is handy!

Schematic:
http://i132.photobucket.com/albums/q...hema111108.jpg

View:
http://i132.photobucket.com/albums/q...r/Dscf1436.jpg


-Bill WX4A/KP4


Nothing that pretty can possibly work.

:-)

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html