My Theremax

Posted: 1/9/2006 10:18:29 PM
De Futuraa

From: pittsburgh

Joined: 1/9/2006

I recently purchased this kit without any prior knowledge of soldering or the like. I'm building my theremin as a school project in order to graduate. I've just recently began soldering the bare wires and the resistors. Being inexperienced ive been pressing the leads flush with the circuit board and then applying the solder on top, then clipping the excess lead with diagonal wire cutters. Its say's in the instructions that you should have about 1/16 inch of lead passing through the solder. Will my technique affect my end result? should i go back and attempt to resolder?
Posted: 1/10/2006 12:24:41 AM

From: Kansas City, Mo.

Joined: 8/23/2005

Sounds like you may end up with some loose solder joints (often call "cold joints") and it is easily remedied by reheating the solder joints. Be careful with the coils!!!! I repeat, do not overheat the coils!!!

The other parts are fairly resilient.

To explain the soldering process, you are conducting heat from the tip of your soldering iron to the circuit board trace and the lead -- the heat from them in turn causes the molten solder to flow around them and secure the joint.

Solder also conducts heat, so you will want to "tin" your solder iron's tip -- in other words, melt a little solder on it so that there is a thin coat of solder to conduct the heat from the tip to the parts being soldered.

A "cold joint" is one where the solder iron melted the solder and the solder flowed around the metal but the metal was too cold to melt the solder -- the result being a weak, intermittant, or totally non-conductive joint.

You don't want to overdo the tinning... too much solder and you risk globbing it onto adjoining traces/leads. Examine your work with a magnifying glass and be -- well -- uh, be really really fussy about everything.

Also, when you first turn on your solder iron, you may want to solder a few joints for practice... just solder wires together, etc. This assures that your solder iron is tinned and sufficiently hot to do the job.

How hot is hot enough? Well, when you press solder against the tip, the solder should melt immediately.

You have come to the right place for help, encouragement, and advice. You will find many folks that restore antique electronic equipment, build kits, build from scratch, electrical engineers, ham radio operators -- all here on I am in the "kit builder" category, myself.

Good luck with your Theremax. It is a fun project!
Posted: 1/10/2006 12:05:34 PM
De Futuraa

From: pittsburgh

Joined: 1/9/2006

wow thanks so much. the thing is that when i was soldering with my original technique, the iron was melting the solder just fine. It would flow right onto the joint. But i was worried that if the lead wasnt passing directly through the solder it would cause a problem. thanks again for being so helpful.
Posted: 1/18/2006 12:24:21 AM

From: Ma

Joined: 10/4/2005

good luck with your theremax!

My parents bought one of these kits for me for my birthday, and i had a great time puting it together. i also had no experience in soldering before i built this and did not have to much trouble. except i accedentaly soldered the entire front panel backwards. but it is now fully functional.
have fun!


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