Ever do this?

[jcollins]

Broken reverb tank. Output reads open.

Rewound the coil.

It worked.

[booj]

How did you wind the coil?

[Rob Mercure]

Nope but I've unwound a turn or two and resoldered coils and since I've got a stock of pans with one coil open that I've accumulted over the years I've swapped the coil from one pan to another to either get a good pan or change impedance if I didn't have the right impedance pan at the time.

Rob

[52 Bill]

I've done this before, but there is no way to do it economically. It is far easier to replace the tank with a new one.

If you want to try it and have the ability to work with very fine wire, here's how I have done it.

1-Dis-assemble the dead coil from the tank. This will require you to unsolder the leads from the RCA jack or unplug the connector. Then you need to drill out the rivet that secures the laminated core structure from the tank transducer. To remove the core structure, you will need to remove the springs. In older tanks, they will just un-hook, on newer tanks they will be glued on. Be carefull here, if the tiny suspension wires that the springs attach to break, the entire transducer will need to be replaced. Remove the core and slide out the coil form.

2-Un-tape the coil and find the coil end wire. Un-wind the coil. I place the coil onto a spindle, (a small nail in a board). Then I put a short 3/8" dowel rod in a power drill. I use a slow speed and use the drill to wrap the coil wire onto the dowel and off of the coil form.

3-Find the break in the wire. If you're lucky, the break will be near the outer end of the winding. If it is, you can either just resolder the end of the wire to the output lead, or you can solder the two ends together re-insulate the wires with some clear nail polish and re-wind the wire back onto the coil form. The worst case will be that the break will be at the very end of the coil and you will have to completely un-wind the coil.

4-Rewind the coil. Chuck the coil form on a drill using a small nut and bolt to secure it in place. Then using a slow speed, wind the wire back onto the coil form. It's kind of like winding a guitar pickup. Try and keep the wire layered evenly as it fills the form. When all of the wire is on the form, resolder the lead wires and retape the coil.

5-Re-assemble the coil into the transducer. You will need to find a small nut and bolt to replace the rivet that you removed earlier. Re-attach the springs and resolder the leads to the RCA jack.