LinkBack Thread Tools Search this Thread Display Modes
Prev Previous Post   Next Post Next
  #1   Report Post  
Old November 11th 04, 05:42 AM
Dale Parfitt
 
Posts: n/a
Default Update: Home-built air-gap variable capacitor


"Lars Janqqvist" wrote in message
...
Frightening the yaks, -=jd=- just had to say:

It wasn't nearly as difficult as I had anticipated.
I finished up with 14 rotors and 15 stators.

The meter says 7pF with the plates unmeshed, and 314pF with
the plates fully meshed.

The trickiest part was patiently (and subtly) straightening
the plates after assembly. Cumulative time spent building it
was probably 4 hours. After building the first one, you
realize that the plates don't have to be perfectly cut - they
just have to rotate all the way around without contacting
anything. Just as the Cajuns know that "looks don't make it
taste good", capacitor plates that aren't cut exquisitely neat
don't mean it won't... um... "capacitate"...

-=jd=-


re uneven plates: The linearity will suffer but unless you're
calibrating it to something (tuning dial, antenna load) that
shouldn't matter.


I don't see anything linear in F vs C for a resonant circuit. In fact, in
order to make it anywhere close to linear, one has to go to extremes with
the shape of the plates.

Dale W4OP


 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
FA: Yaesu FT270R Yaesu FV101-Z Cardwell Air Variable Capacitor Will Dx 0 April 16th 04 12:07 AM
FA: Yaesu FT270R Yaesu FV101-Z Cardwell Air Variable Capacitor Will Equipment 0 April 16th 04 12:07 AM
FA: Yaesu FT270R Yaesu FV101-Z Cardwell Air Variable Capacitor Will Homebrew 0 April 16th 04 12:07 AM
Looking for variable capacitor... Rightrik Homebrew 4 July 27th 03 07:32 PM
Looking for variable capacitor... Rightrik Homebrew 0 July 26th 03 07:10 PM


All times are GMT +1. The time now is 02:54 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017