[Amps] 160M PI network Toroidal Coil

Bill Turner dezrat1242 at yahoo.com
Sat Oct 5 23:43:56 EDT 2013


ORIGINAL MESSAGE:          (may be snipped)

On Sun, 06 Oct 2013 00:25:36 +0000, Manfred wrote:

>You are wrong regarding the loss. The loss isn't "essentially zero", 
>unfortunately. Such a coil will likely end up having a Q between 300 and 
>350, perhaps lower if other metal objects are too close to it, or if it 
>uses some lossy support. Now if the loaded Q of the tank circuit is 12, 
>as is often done by design, then the coil will loose about 4% of the RF 
>power. At 1500W output that would be 60 watts, which is enough to make 
>that coil very hot, unless there is a strong stream of air cooling it.

REPLY:

I stand by what I said. I have such a coil in my homebrew 8877 amp using #4
wire and it runs barely warm with the key down. I call that "essentially
zero" in the sense you'll never notice it. 

73, Bill W6WRT
 


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