Coil & Variable Capacitor Combo for Regen & Crystal Radio Projects (8-pin octal)

Description

For those projects where you might need a finished inductor and variable capacitor kit.
The finished inductor is about 335uh, with a 90uh tickler winding, as shown on the hand sketched drawing. The coil is about 55mm tall x 43mm diameter (inc. the pull ring on top). The actual diameter of the main body of the coil is around 38mm.
Several configurations are possible. The polyvariable is a 2-section, 160 and 40pf. Actually, according to my L/C meter the total inductance is 210pf plus, with both sections connected in parallel. Each section also has adjustable trimmer caps, at least 10pf each.
With the main coil and the included capacitor, the tuning range is roughly 580 to 1950 khz, with both capacitor sections connected in parallel.
If you connect pins 2 & 3 together and use the entire coil for a crystal receiver, then you'll be able to tune much lower in frequency, down into the long wave spectrum, especially if you want to shunt a fixed capacitor (maybe 200pf) across the variable 210pf variable.
If you want to use this coil for a regenerative receiver requiring a cathode tap connection, then just jumper pins 2 & 3 of your octal chassis socket, ground pin #4 and use pin #1 for the top of the coil. That way you'll have around 425uh for a total coil inductance.
So lots of possibilities with this coil/capacitor combo.
I make these to order, with all new parts.