Vaccume Variable Capacitor

[stepper001]

Hi,

1st post. Im not an engineer, but rather a learning amateur of Ham Radio. Im planning to build a Magnetic Loop for HF SSB phone. It is made of copper 28mm OD with a 3.2' inside diameter. The power used is 100W max and a gamma match is intended to be used, I want also to control the tuning over the 20-10mtr bands with Vaccume Variable Capacitor. Now the VVC Im looking at is a 2-100pf 5KV capacitor. What Im interested in learning is...how many turns does this type of capacitor take from completely meshed ( closed ) to fully open?

 

When I find out this information I can ask about Stepper , Driver spec for the VVC.

 

All good advice welcome,

 

stepper001

[TonyMcC]

It probably varies with different capacitors and/or manufacturers. You need a specification sheet (imo). One example is shown in fig.3 of the link showing 25 turns. (10 truns looking "useful").

 

http://www.hatdaw.com/papers/sb_12.pdf

Edited February 25, 2011 by TonyMcC