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[Amps] Ferrite Core for 160M PI Output ?

To: <>
Subject: [Amps] Ferrite Core for 160M PI Output ?
From: "Jim Thomson" <>
Date: Tue, 13 Jun 2017 02:41:59 -0700
List-post: <>
Date: Mon, 12 Jun 2017 15:44:33 -0700
From: Paul Baldock <>
To: "Carl" <>,<>
Subject: Re: [Amps] Ferrite Core for 160M PI  Output ?

<I understand insulating between the wire and the core, but why do you 
<need to insulate the two cores from each other?

##  Extra reliability.   If each core is wrapped 1st...then its wrapped 360 deg
around each core.   If you instead  wrap the entire mess of stacked cores, you
end up with  air gaps here and there.   Do both, and its bullet proof, with no

##  If you use polyimide wire..which I believe is the same as kapton.... for the
magnet wire, in the bigger gauges, its  15 kv rated.    Like for  14-12-10-8 

##  Then it becomes  30 kv between adjacent turns  and  15+  between wire and 
But polyimide magnet wire is not cheap.   But its bomb proof..and cheap 

##  If you really want to go crazy,  you can also slide some teflon spaghetti 
tubing over the
polyimide wire.  Array solutions uses that technique on some of its  9-1 un-uns 
and other applications. 

## On a side note, If I remember correctly, the Ameritron amps used torroids on 
160m..and maybe 80m as well.
They used a PI-L on 160m,  and maybe 80m too..and def a PI on the other bands. 
The idea was to be able to use a smaller load cap, and or less padding.    I 
believe their was an issue when running
RTTY on 160m, or any other CCS data mode.  The torroids cooked.   If I remember 
the story, Ameritrons response 
was they assumed no one would operate RTTY on 160m. 

Jim  VE7RF

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