Electronic – How to fix these broken wires

1. If you unwind one turn of the coil, you will detune the antenna. At 125 kHz, the coil should have many turns and maybe this won't throw it off so far that it doesn't work. But if you have two broken ends, you would be tempted to remove two turns. That would be even worse. You might be able to add some capacitance to bring it back in tune.

2. Reattaching the wires by, in effect, splicing in some more wire, will work, especially at this low frequency. There are some mechanical issues with those #26 wires; they will seem huge and will want to pull out the tiny wires, but electrically, it's sound. It's the approach I would take, especially if I really just wanted to see if that really was the problem in the first place.

3. Some types of insulation will burn off so you can solder, but many times it won't, and then you have to scrape the wire. That's a challenge in itself. I would not bother trying to apply more insulation unless I didn't think I could prevent the wires from touching.

In answer to your questions,

1. Remove the third lead, this will let you clear/prepare the pads for re-soldering.

2. It's probably best to flick the old solder off the leads; do this by heating and bending the lead with the tip of the iron and letting it spring back, DO NOT DO THIS TOWARDS YOUR FACE!

3. You can buy solder with a flux core. Also, if you can get it, buy lead solder, it is MUCH nicer to work with.

As regards the vid:

Yes the guy tins his iron to remove the leads, you should always tin (add solder to your iron tip) before you do anything, it stops the tip oxidising. It also helps when melting old solder.

To clean the pads generally I would put a bit of new solder on, then wick it off to give a nice clean and shiny surface.

He is applying flux, this will stop the solder "balling up" and sticking to stuff it shouldn't. You can do this, but if you are careful, and have flux core solder, you wont need to.

As regards the rest of your questions, this is just about technique. The guy seems to tack solder (a connection made to hold it in place) the leads at first. When the whole lead is tack soldered he goes around and tidies up the job.

So what YOU need to do.

1. Remove the lead - Tin and clean the pads and flick the old solder off the end of the lead (NOT TOWARDS YOUR FACE!)

2. Add a little solder to each of the pads

3. Place each lead above the pad and push down gently whilst touching the tip of the iron to the solder you placed on the pad. Make sure you remove the iron before removing the pressure.

4. When all connections are made, get some tweezers and push down on each lead in turn, melting the solder on the pad with the tip of the iron so the lead is properly flat on the pad.

Remember! Before you touch the iron to anything, make sure you have applied some solder to it and wiped it off on a sponge.

Also, if you are buying new equipment, when you first turn the iron on, keep adding solder to the tip and wiping it off. You need to thoroughly tin/protect the tip before you start using it. You can get little pots of hard flux, this is useful and it will help remove the crud on the tip due to oxidation. Also, tin it and DON'T wipe it off when you are done, the tip will still be hot for a while after you switch it off.