07-03-2020, 05:21 PM
Bro,
As for your coil you could backwards engineer it by using an inductance/cap calculator. Use a capacitance meter to confirm the value of the osc section of the tuning cap. I would think it would be around 350-400mmfd. Use the calculator to figure the inductance to tune the frequency of the osc (810kc to 1760kc). Also check the operation of the trimmer. It should vary the capacitance by 10 or 20mmfd
Then use an inductance calculator to figure how many turn of what size wire on a given size form will give you the proper inductance. This is for the top half of the tapped coil. The bottom half is the feedback section. Using a triode osc typically that winding would be about 15% of the total of the top winding.
If you just want to wing it 85t of 38G and 14t of 38g for the bottom winding. This would be a starting point. It may or not work.
GL
As for your coil you could backwards engineer it by using an inductance/cap calculator. Use a capacitance meter to confirm the value of the osc section of the tuning cap. I would think it would be around 350-400mmfd. Use the calculator to figure the inductance to tune the frequency of the osc (810kc to 1760kc). Also check the operation of the trimmer. It should vary the capacitance by 10 or 20mmfd
Then use an inductance calculator to figure how many turn of what size wire on a given size form will give you the proper inductance. This is for the top half of the tapped coil. The bottom half is the feedback section. Using a triode osc typically that winding would be about 15% of the total of the top winding.
If you just want to wing it 85t of 38G and 14t of 38g for the bottom winding. This would be a starting point. It may or not work.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
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