[AMPS] Supressors on my 4-1000A

[Jon Ogden]

>I would bet that a coil of #18 guage wire has about the same 
>inductance as a coil of silver plated strapping (same coil diameter & 
>number of turns).  I haven't measured this yet with my dip meter, but I 
>think it would be an interesting experiment, so I will do that and report 
>back.

Ok, the experiment is done and my bet was wrong!  The #18 ga wire has 
about 1.7 times the inductance of the strap.

Here's the results of the experiment:

Silver plated strap:

Measured the resonance of the strap in parallel with an 1800 pf mica 
capacitor.  Resonant frequency was 13.5 MHz.  Calculated L=77.2 nH.

Measured the resonance of a coil of #18 Ga magnet wire in parallel with 
the same 1800 pf cap.  The coil tried to duplicate the strap in diameter 
and length as much as possible.  Resonant frequency was 10.3 MHz.  
Calculated L=132 nH.

However, given these facts, I am wondering why the strap coil still burnt 
up the resistors even though it is less inductive than a magnet wire 
coil.  I suppose I could measure the inductances of my current supressor 
vs. the strap, but it's getting too late tonight!

One would think though that 77.2 nH would be a decent value to use as a 
supressor coil.  However, I think AG6K recommneds around 52 nH or so for 
a 4-1000A.

More on my thoughts on this later.....

73,

Jon
KE9NA



-------------------------------------
Jon Ogden
KE9NA

http://www.qsl.net/ke9na


"A life lived in fear is a life half lived."




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