[Amps] TMC amp toroid tank

[Gary Schafer]

> -----Original Message-----
> From: Tom W8JI [mailto:w8ji at w8ji.com]
> Sent: Monday, March 26, 2007 9:54 PM
> To: garyschafer at comcast.net; amps at contesting.com
> Subject: Re: [Amps] TMC amp toroid tank
> 
> > I could see really killing it if the turns were shorted
> > but this amp uses
> > taps on the toroid coil it does not short the turns.
> 
> I don't understand that.
> 
> Surely at least one end is tied to a tap point!
> Let's assume the thing has 20 turns and the 20 MHz tap point
> is at 4 turns. If the 4 turn tap was selected withouit
> shorting the end, you would have a 1:5 voltage step up.
> 
> My bet is they may not have a progressively shorting switch
> but they still short a large portion of the unused winding
> when on higher bands.
> 
> Shorting one turn or ten, it is a bad ideal in a closed
> core.
> 
> 73 Tom
> 
> 

Yes you are right Tom. It gets taped from the antenna side as a normal tank
coil would. No progressive shorting. So on 20 meters most of the coil is
shorted. It seems to work very well on 160 and 80 meters however. 40 meters
things start to fall off. 
Why do you suppose it still works well on 80 meters where nearly half the
coil is shorted?

73
Gary  K4FMX