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The photo on the left shows the coil winder I made in order to do the wave winding. below are photos of the sample and the remade coil. The single layer coil on the sample was approx. 65 turns of Litz wire. The wave wound coil was very narrow and high. This was also wound with Litz wire. The only wire I had was 0.16mm enameled copper wire. The original former was available. Temporary side cheeks were made using plastic tube to prevent the coil from collapsing and 200 turns were wave wound on, the turns being progressively secured with nail varnish. The same wire was used to wind the 65 turn single layer coil. Not surprisingly the original and the copy are electrically different, but in the newly restored and aligned receiver, the re-wound coil performed perfectly. For more about the winder and Meccano select the next page.

Original coil.
DC resistance 21 ohms
Inductance 1.25mH (Marconi 1khz bridge)
Capacitance 17pf (Analyser at 15Mhz)

Copied coil
DC resistance 12.7 ohms
Inductance 1.05mH Marconi 1 khz bridge)
Capacitance 20 pf (Analyser at 15Mhz)