Wire and solder.

[Martin Bush]

Hello again

I am now at the point where I have got my first radio powered up and working but I am encountering a bit of ragged wire under the chassis - perished rubber etc.

What is the advice regarding wire? I don't have the space or knowledge to make use of multiple reels, but I was wondering if there was a standard type ti could get that was good for replacing dodgy lengths and perhaps things like the wires to the speaker.

Secondly, I know that I need 60/40 lead solder (I have a small amount purchased from the market under the 'blackspur' brand). Is there a specific brand I should get or am I safe selecting something from a UK seller on ebay for instance?

Martin

[julie_m]

16/0.2 is a pretty "universal" grade of hookup wire. (The designation means 16 strands, each 0.2 mm diameter, and works out about 0.5 mm² total cross-section.)

You'll need something a bit heftier for carrying several amperes over long distances, but a few 10-metre packs of 16/0.2 in a few colours will be a good start to your collection.

[paulsherwin]

I mostly scavenge hookup wire from scrap computers and other equipment. If you need single core, a length of ring main cable from a skip will provide all the heavy duty stuff you need, while a length of 6 or 4 wire telephone wiring cable will provide the thin stuff.

Generic solder will be fine, just avoid the lead free stuff.

[kalee20]

Make sure it is generic electrician's solder though, not plumber's!

[Oldcodger]

If you are not using a soldering station with a tip cleaning sponge, then a small piece of damp foam works equally well. Can't say which type as i use the one that came with my soldering station. In addition a small pot of flux ( plumbing supply place ) is useful , even with resin cored solder, but as said 60/40 is the correct type. I've only seen plumbers solder used in the coil stages of a high power transmitter.

[crackle]

I use a stainless steel scouring pad, just wipe the iron tip over it and it comes up clean ready for tinning again.

Mike

[Oldcodger]

Never tried that one, been spoiled with soldering stations, but I find that dipping tip into flux pot ( make certain it's not an acid type) ,cleans the tip nicely,with a shiny tinned tip.

[Herald1360]

http://cpc.farnell.com/multicore-sol...00g/dp/SD00965

is good quality leaded solder suitable for our kit.

It's not cheap- neither tin nor lead are either.

http://www.maplin.co.uk/p/multicore-...05k-reel-r32yh

is twice as much of same stuff at similar unit price.

[Martin Bush]

Thanks to everyone who has responded so far.

I will be delving into the skip round the corner in the morning - I spotted some mains cable in there earlier (I'm becoming the village Womble).

Also, regarding the scouring pad, I have seen that done myself. Apparently it doesn't cool the iron in the same way as a wet sponge does.

[Herald1360]

A lot of new iron stands now come with a sort of loose brass scouring pad rather than the sponge of yore. It works fine and never dries out

It's also easier to use on hot tongs bits for SMD stuff.

[saxmaniac]

An old trick with an uncontrolled iron such as an Antex was to wire in a switch with a diode in parallel possibly incorporated into the stand so that when the iron rested on the stand the switch opened leaving the diode in series with the iron thus halving the power and extending bit life

[MajorWest]

Originally Posted by Martin Bush

What is the advice regarding wire?

I keep my eyes open. The best I got so far was wire from a boiler, ideal especially for transistor radios. I also found telephone wire is great for PCB's and I tend to double it up as it's so thin so I wind one around the other and then soldering it is easy.

I found if the wire is too thick it can be much harder to solder. For instance, when using radial caps I experimented with single core copper wire to create leads on lugs or maybe make loops at the edge but soldering thick core like that was tricky to get a really good joint.

I have used AC wire and can get by with it but dislike the fact it seems to not tin so easily. The boiler wire is a pleasure to use and is multi-coloured, red, green, blue and so on.

[Denis G4DWC]

Martin

I can find you some various coloured wire and the best part of a 500g reel of 60/40 solder FOC when you collect the other items you wanted.

Regards

Denis

[sobell1980]

what about the voltage rating of wire being used ?Or is its amperage / current rating more important and the gauge, so as it doesn't overheat if drawing too many amps than the wire can handle.
Dave.

[Martin Bush]

That is the question I was going to ask Dave. I'm still at the stage where my lack of knowledge means I'm very careful when changing things round.

[julie_m]

Most modern PVC-insulated equipment wire is considered pretty safe for mains and normal radio HT voltages in an enclosed environment, and will certainly withstand mains between two lengths in intimate contact.

If you feel paranoid, you can pay extra for "tri-rated" equipment wire; which is tested to the most stringent standards required by three different approvals bodies, so should be good enough for anyone.

The thicker the wire, the less voltage drop it will exhibit per metre per ampere. HT wiring will, by definition, not be carrying much current anyway; and it's hardly as though you haven't a fraction of a volt to spare. Ordinary 16/0.2 will even do for heater and loudspeaker wiring in radios and record players; but you should use something rather beefier if you are building a high-power amplifier (a rectifier or output valve heater can easily draw a couple of amps).

[sobell1980]

I have been using in the past 3 amp wiring on a roll PVC
insulated. It was laying around in my garage and I suspect it is for automotive use. That was the reason for me asking as it had no voltage rating on it. But with my mains powered radios and record players being fitted with a 1 AMP mains fuse I assumed that this 3 AMP wire I have been using is certainly beefy enough even if it is not rated at mains voltage. I'm not into power amps etc so I'm sure what I have been using is ok?
Dave.

[dseymo1]

In case it's not obvious, it's best to to use stranded wire if it's likely to be subjected to movement or vibration. Solid-cored wire, on the other hand, can be self-supporting, and is easier to connect tidily to lugs on tagstrips, switches and so on.

@ Dave: While your '3A' wire is undoubtedly adequate for your purpose, bear in mind that a draw on the mains of 1A does not rule out significantly higher current at lower voltage within the equipment.

[Herald1360]

3A automotive wire may well be larger cross section copper than you would expect, since voltage drop is of more concern at 12V than 240V; the same applies to heater wiring. The insulation (unless it is really modern) will probably also be much thicker than needed for dielectric stress, simply for physical robustness in the automotive environment, and will be adequate for radio voltages.

In certain areas of radio, ambient temperature may be more of a problem- PVC shouldn't run hotter than about 70C- far too hot to touch metal though less than spit sizzling hot.

If you're really unsure about a wire's rating, count the strands and measure their diameter with a vernier or micrometer. Then calculate the total copper cross section and refer to Doctor Google!

[julie_m]

There's also http://blog.earthshod.co.uk/?page_id...s that I wrote ages ago, about working out voltage drop in cables.