c24 Technical reflexions about constructing coils

Coils (under work):

Calculating coils:

where L (ÁH) = inductance. d= diameter in cm, l =length in cm, N = turns.


Prahn 5013

Prahn 5014

*) Note the link should have magnetical coupling to the coil, and should be placed at the bottom end of the coil.
The right picture shows a coil with similar socket as for Tech TE15 dip-meter.

Once popular slug-tuned coil, but the rather long screw makes it very little practical to use!

American pre-war ready-wound coil, bought at an auction in Oslo last autumn.

Disc-coils, the latter from a HE 1 type Wehrmacht receiver. (LA6NCA).

Crosswound coil


Tunable iron-powder toroid coil

Frame type coil

German coils for HF and VHF

RF chokes (mostly German)

German RFC's and audio chokes and mike-transformers.

Ceramic coils used in German transmitters

German IF bandpassfilters

An unknown tunable coil (LA6NCA).

Components from German equipment on
page f21 and f22

Capacitors (the pictures will be moved to another page later).

Differential capacitors (2x 60pF and 2x 5-25pF), se page ...