How to solder this connector ( Cal Test CT2228-4 )? - Page 1
Forum section: electronics / beginners

author: Thomas Ballantine
author_rank: Contributor
timestamp: August 14, 2025, 09:29:06 pm
content: I'm going to add 2 of these banana plugs to my Hameg for a handy bit of power supply (12V and 5V from the internal test points), and I was wondering how to solder to the back of them. Searching for "solder hole soldering", but that's not much help. Any ideas?

author: Analog Kid
author_rank: Super Contributor
timestamp: August 14, 2025, 09:42:11 pm
content: Pretty easy.Strip the wire and fold it enough times to at least somewhat fill up the hole (2-3x).Solder the end as you'd solder anything else.Done.If you think the wire you're trying to solder to it is too thin, take a short piece of thicker solid wire just a little smaller than the hole, wrap the wire around it so it just fits in the hole, put it in the hole and then solder it.Oh, and be sure to put the nut on the wirebeforesoldering if there's something on the other end of it.

author: Vovk_Z
author_rank: Super Contributor
timestamp: August 15, 2025, 09:57:28 am
content: It may be easier to not solder it but to use nuts. Are there some?IF you want to solder, then use a powerful soldering station, like T12 should do the job. Carefully try not to melt a plastic part,

author: Thomas Ballantine
author_rank: Contributor
timestamp: August 15, 2025, 11:07:33 am
content: There's a nut with it, but it's for clamping the socket to a panel, although I could pair it with a washer to make that work. Think I'm good to go ahead and solder it though

author: tooki
author_rank: Super Contributor
timestamp: August 15, 2025, 11:10:02 am
content: Quote from: Thomas Ballantine on August 14, 2025, 09:29:06 pmTreat it as you would any other solder cup:1. Strip and pre-tin the wire. Test the strip length against the depth of the cup: the wire insulation should be about 1/3-2/3 wire diameter away from the cup. (So for example, if your wire has insulation with a diameter of 2.4mm, then the gap between the cup and the insulation should be between 0.8-1.6mm.)2. Pre-fill the hole about 2/3 of the way with solder. (For example, take solder that is about as thick as the hole, insert it into the hole, and then cut it flush. Then heat with the iron to melt it.)3. Heat the solder cup with the iron to remelt the solder, then insert the pre-tinned wire into the molten solder. Remove the iron, and hold the wire still until the solder solidifies.(With practice, you can often combine steps 2 and 3, in that you only melt the solder once.)Important: you need a large soldering iron tip for this. A small tip will not be able to heat the joint quickly enough, which ironically can lead to damaging the plastics on the other end.P.S. Do you really want to risk damaging your Hameg by using it as a power supply? If something goes wrong with the device you’re powering, you could damage the Hameg.

author: BILLPOD
author_rank: Frequent Contributor
timestamp: August 15, 2025, 12:44:23 pm
content: Good Morning Thomas, You've been given lots of good advice. My contribution is to apply heat only long enough to melt the solder, to avoid melting the blue plastic, (it doesn't appear to be removable. I am curious as to what will plug into a blue socket.

author: tooki
author_rank: Super Contributor
timestamp: August 15, 2025, 12:48:45 pm
content: One tip to avoid damaging the plastic: screw on any nuts it came with and move them close to the plastic (=added thermal mass), and wrap a wet strip of cotton cloth or string around the thread where it meets the plastic.