The circuit diagram for my Airline model 84WG-2714-g
calls for the Signal Generator to be connected through a dummy antenna. An old radio book provides a wiring diagram as .. .0002 mfd cap wired in series with a parallel circuit consisting of 1) a 20 uH coil and 2) a .0004 mfd cap and 400 ohm resistor in series.

I have 22, 26 & 30 gauge magnet wire and was thinking of winding the wire on either a small diameter dowel or nail. Am I on the right track here?

Can someone help with a formula (# turns, nail versus dowel, air etc.) to wind a 20 uH coil?

Thanks

Steve

Steve, the schematics that I have either use a .1 MFD capacitor for a dummy antenna ( one lead connected to the signal generator and the other to the given point in the circuit ) or say to loop several turns of wire and connect the signal generator across the coil. The coil acts as transmitting antenna for the signal generator. I hope that works. Bart

: The circuit diagram for my Airline model 84WG-2714-g
: calls for the Signal Generator to be connected through a dummy antenna. An old radio book provides a wiring diagram as .. .0002 mfd cap wired in series with a parallel circuit consisting of 1) a 20 uH coil and 2) a .0004 mfd cap and 400 ohm resistor in series.

: I have 22, 26 & 30 gauge magnet wire and was thinking of winding the wire on either a small diameter dowel or nail. Am I on the right track here?

: Can someone help with a formula (# turns, nail versus dowel, air etc.) to wind a 20 uH coil?

: Thanks

: Steve

The formula is;

L= self inductance in microhenrys,
N= total number of turns
R= mean radius in inches
l = length of coil in inches
B= depth of coil in inches

Single wound coils,

L= (rN)squared over 9r+10L

N= squareroot/L(9r+10L) over R

Wire Gauge or AUG:

22 = .02535
26 = .01594
30 = .01003

From Allied's radio data handbook 1943

: The circuit diagram for my Airline model 84WG-2714-g
: calls for the Signal Generator to be connected through a dummy antenna. An old radio book provides a wiring diagram as .. .0002 mfd cap wired in series with a parallel circuit consisting of 1) a 20 uH coil and 2) a .0004 mfd cap and 400 ohm resistor in series.

: I have 22, 26 & 30 gauge magnet wire and was thinking of winding the wire on either a small diameter dowel or nail. Am I on the right track here?

: Can someone help with a formula (# turns, nail versus dowel, air etc.) to wind a 20 uH coil?

: Thanks

: Steve

sorry, should be a 10(length) in both those formulas
(it would appear as 10l)!

: The formula is;

: L= self inductance in microhenrys,
: N= total number of turns
: R= mean radius in inches
: l = length of coil in inches
: B= depth of coil in inches

: Single wound coils,

: L= (rN)squared over 9r+10L

: N= squareroot/L(9r+10L) over R

: Wire Gauge or AUG:

: 22 = .02535
: 26 = .01594
: 30 = .01003

: From Allied's radio data handbook 1943

: : The circuit diagram for my Airline model 84WG-2714-g
: : calls for the Signal Generator to be connected through a dummy antenna. An old radio book provides a wiring diagram as .. .0002 mfd cap wired in series with a parallel circuit consisting of 1) a 20 uH coil and 2) a .0004 mfd cap and 400 ohm resistor in series.

: : I have 22, 26 & 30 gauge magnet wire and was thinking of winding the wire on either a small diameter dowel or nail. Am I on the right track here?

: : Can someone help with a formula (# turns, nail versus dowel, air etc.) to wind a 20 uH coil?

: : Thanks

: : Steve

: The circuit diagram for my Airline model 84WG-2714-g
: calls for the Signal Generator to be connected through a dummy antenna. An old radio book provides a wiring diagram as .. .0002 mfd cap wired in series with a parallel circuit consisting of 1) a 20 uH coil and 2) a .0004 mfd cap and 400 ohm resistor in series.

: I have 22, 26 & 30 gauge magnet wire and was thinking of winding the wire on either a small diameter dowel or nail. Am I on the right track here?

: Can someone help with a formula (# turns, nail versus dowel, air etc.) to wind a 20 uH coil?

: Thanks

: Steve

Thanks

I will give it a try.

Steve