The AM Forum

I know there are charts listing plate spacing vs voltage for variable capacitors. Is there any chart or formula for coils in a Pi Network? I ran across this in my jonque box. It has a nice shorting switch. It appears to be 15-80 meters, is 2" by 3" with perhaps 16 or 14 gage wire. Turns are spaced 1/8" and it needs the separate 10 meter coil. This may have come from a Heathkit. How do I determine its power-handling capacity?

If the coil is 16 or 14 gauge it should be able to work to 100 Watts.

There are spreadsheets for Pi-networks but they don't determine power handling capabilities, they only give values for the Shunt-C, Series-L, and Shunt-C components.

How do you know it needs a separate 10 m coil? Have you measured the inductance and have a schematic of the Final stage?

Are you homebrewing?

Phil - AC0OB

I was thinking of using it for an AM rig with parallel 5933s running about 120 watts. The switch is 5 positions. Each position shorts out one portion of the coil. In the fifth position, the entire coil is shorted so it will require a 10 meter coil.

This appears to have come out of a Heathkit Apache so it can handle 180 watts CW and 150 AM.

No doubt about it.   8)

Here is a pic of the RF cage from the Apache now on my bench for a Cap upgrade.

Phil

That be it alright with a nice shot of the 10 meter coil.

Thanks!