Very fine (hideable) microphone wire

Jon D wrote in news:Xns98B8E4A6C37B117E53A@127.0.0.1:

Any thin coax will do if you only need it to run a few feet. If you really want it close to invisible, build a balanced line input amp and run it from a twisted pair. That could be made out of fine enamelled wire chosen to match hair colour, it could be damn close to invisible, even in good light at close range.

Lostgallifreyan wrote in news:Xns98B8E6EAFCC43zoodlewurdle@140.99.99.130:

If you're not concerned with visibility, and just want thin-ness for other reasons, get a cheap pair of walkman headphones and take the cable from those. It's usually coaxial, and is as thin as you're asking for. It's also very weak crap usually, but you get what you pay for. Even if you waste a plug and an earphone you'll still get it cheaper per meter than buying it straight, and I think you'll find the added plug a bonus, it will probably fit your player.

If I want a length of thin co-ax cable, I chop the video lead from a scrap monitor and strip one out of that. 75ohm and usually good quality too. A bonus is its in multiple colors!

The twisted pair idea seems nice but wouldn't be suitable for my case.

Does the coax have to be specifically "mic coax"?

I would just take two lengths of enamelled copper wire, twist them together, and see if that works OK.

Jon D wrote in news:Xns98B8F19F56D0517E53A@127.0.0.1:

Nope.. Short lengths for audio with limited bandwidth like small electrets have, is one of the least demanding things. Depends how much noise you can tolerate. If that noise is regular you can remove it from recordings with software, but it's still worth trying to reduce at source if it's intrusive.

Try what Baron said, find the cores of an old monitor cable, I never thought of that before, it is probably very good stuff.

Even without the balanced line, the twisted pair might be workable. Worth trying just to see how it goes.

I'll try it but I would half-expect the most awful hum near mains equipment.

Sometimes things just work out better than expected. I've seen it happen many a time.

"If it ain't broke, don't fix it".

If it's twisted pair it may work fairly well - certainly worth a try.

Jon D wrote in news:Xns98B98D73D09E17E53A@127.0.0.1:

I doubt it, because the pair will be well twisted, and the hum will cancel more than cause bother. Also, the main problem with mains is induction, and an electret mic circuit has a high impedance, so not much current can be induced. Try it. If the noise is unacceptable even over the short distance you're using, use coax from cheap earphones, like I said, or from an old monitor cable, as Baron said. I won't say anymore, I'm repeating myself already now.

for short run ( I am in the UK. I have an electret mic capsule and want to connect it

I am the OP.

I have to confess that I don't know much about twisted pair wiring except that it's often mentioned with ethernet.

(1) Could I make my own twisted pair wiring to attach my minature microphone capsule by getting two reasonably fine wires and twist them together? If so then would something like four to five twists per inch be about right?

(2) Could I use the wires from an old-style magnetic earpiece? For example

Can I buy a few feet of "flat copper laminated sheet wire"? I can't find it on Google or Froogle.

Is it something which has to be cannibalised from defunct electronic equipment?

Jon D wrote in news:Xns98B9B57F81DF517E53A@127.0.0.1:

It's very common. Most mains cables use twisting so that the induced field strength falls off sharply with distance from the cable.

You can make it easily by taking two parallel lengths of single-core stranded insulated wire and tying a small weight on one end of the pair. Hold the far ends up so the weight hangs freely. Spread the held ends, keeping the angle between each length constant, and twist the ends in the same direction, between finger and thumb. The wider the angle, the more twists per inch will result. The more the better, generally. This trick makes a fast, evenly spaced twisted pair.

Definitely, that looks like good stuff. They make them twised with many turns per inch to reduce induced hum, because the earphones have a very low impedance and high sensitivity, so can pick up hum even without much amplification if they didn't have the twisting.

Actually, mains cables have a twist for easy flexing, but it does help reduce inductive coupling, too. The earphone cable also uses it so it flexes easily without causing metal fatigue.

This is a slightly different application.

Don't make it too complicated - just try the simple solution first and change it only if there is a problem.

try the surplus houses, silicon surplus, digikey, electronic goldmine, etc

it is also supplied as power distribution bus wire, not as flat though, (.01 inch thik)

yes, cannibalism is a great way to derive this stuff, only the configurations are very limited that way due to short run pieces.