[Amps] Plate Choke Resonances

[Jim Brown]

On Thu, 28 Jan 2010 11:09:07 -0500, Tim Long wrote:

> Shorting the choke and with a grid dip meter, 

The principal resonance is a parallel resonance with 
its own stray capacitance. You should not have to short 
anything to see this. 

A better way to measure a choke like this may be the 
voltage divider circuit that I use to measure ferrite 
chokes. You need an RF generator and a good RF 
voltmeter (could be a scope -- I use an HP spectrum 
analyzer). See my RFI tutorial. 

http://audiosystemsgroup.com/RFI-Ham.pdf

AND -- as Carl noted, more stray capacitance will be 
added when you actually mount the choke and wire it 
into the amp.  

73,

Jim K9YC