[fields 100]

One of the coils on my 1st detector transformer is caput. Besides the number of turns and rotation direction, how important is the wire gauge? There is some room to go with a thicker wire.Does the coil resistance play important role and how critical is if I go over or under few turns? I so, where can I obtain such wire?
Thanks.

[Roger Cole]

I've only ever rewound an antenna coil and an oscillator coil, but in those cases the wire gauge and exact number of turns wasn't all that critical. I didn't have the exact wire in either case, but I got it as close as I could and made the number of turns as close as I could. The trimmer caps for the antenna and oscillator circuits more than compensated for the error I introduced. My resistances were a fair bit off but it worked fine. (presumably the inductances were much closer)

In my case, it was useless to count turns of wire as I unwrapped the coil because the wire had degraded so much that it came off in pieces. I had read on the forum about counting turns by dragging a pin across the windings, which worked just fine.

I'm sure there are more experienced coil repair people than me, and it might help if you had a pic of the coil you are working on.

Roger

[morzh]

If the coil is the one that goes to the grid, the gauge is less important and can be a bit smaller even. It can be larger if you could fit it.

If the coil is the anode one (the load of the tube's output) go with at least the gauge that was used. While resistance is not awfully important, it i somewhat important, dependent on the current the tube is working at. A bit larger gauge will not hurt you either.

Note: if it is an IF filter-transformer, then you should try to stick to the same gauge as the length of the winding determines the inductance (it is a part of the formula) and deviating too much from it might shift the alignment too much, at least in theory. Simple RF transformer that is not tuned is less critical to it.