Recycling parts

[DIY_Peter]

I want to build my first SS amp. I'm thinking of something like the Elliot P3a.

But I would like to build it using as many recycled parts as possible.

What would I be looking for at garage sales?

old TV's? vcr's? amps probably

Which parts are the most expensive if I buy them new? caps? transformers?

[sayang001]

Look for heatsinks / transformers / caps / housing.

I would buy the other electronic parts new.

[jackinnj]

I wouldn't bother salvaging capacitors, resistors or semiconductors in most consumer electronics -- saying this, I note that my first ham radio transmitter was made entirely from recycled parts -- of course the transformer in a TV was good for 200 watts in the 1960's.

I don't know what the "aftermarket" is for parts in Europe. It is extremely active in the US, and from what I have heard, somewhat active in the UK -- you might want to contact the local Amateur Radio Society and see what they have to say in terms of flea markets, surplus dealers.

I'd be happy to ship an HP6130C to Europe --- great carcase on which to build an amplifier, but the freight would be about $60.

[DIY_Peter]

Originally posted by jackinnj
of course the transformer in a TV was good for 200 watts in the 1960's.

Are the transformers in a modern tv useable?

I don't know what the "aftermarket" is for parts in Europe. It is extremely active in the US, and from what I have heard, somewhat active in the UK -- you might want to contact the local Amateur Radio Society and see what they have to say in terms of flea markets, surplus dealers.

I really don't know about the aftermarket over here. I've never looked into it.
We have a recyling store in my city, where people can bring goods that they don't need anymore, and then they sell it for low prices.
Not much electronic stuff there though... mostly furniture.

I'd be happy to ship an HP6130C to Europe --- great carcase on which to build an amplifier, but the freight would be about $60.

thanks, but i'm not going to buy things from overseas. The shipping is to costly.

Maybe I could ask around at my university. They should have some old stuff with good transformers in it...

[DocP]

Originally posted by DIY_Peter


Are the transformers in a modern tv useable?

Most modern TV's use switch mode power supplies rather than linear ones so they don't have transformers at all that you can use.

I really don't know about the aftermarket over here. I've never looked into it.
We have a recyling store in my city, where people can bring goods that they don't need anymore, and then they sell it for low prices.
Not much electronic stuff there though... mostly furniture.

I think the lack of electronic stuff is probably a safety issue. I know in the UK the charity shops (thrift stores ?) won't take any electrical or electronic goods for safety reasons. I think they are concerned about being liable in the event of an accident.

thanks, but i'm not going to buy things from overseas. The shipping is to costly.

Maybe I could ask around at my university. They should have some old stuff with good transformers in it...

If you can find an old amp that would be a good place to start. I learned a hell of a lot as a teenager fixing up stuff other people were throwing away. At the begining I usually made things worse but I got the hang of it quick enough and got some great kit that way.

As has already been said, the expensive bits are the heatsink, power supply caps and the transformers so these are well worth salvaging if you can.

Good luck

[sam9]

With the dot-com fall out and various bankruptsies, the local electronic surplus shops seem to be loaded with switchs, routers and other comm items that are a source of really high quality but very cheap (<$25 for a 2u rack mountable) cases. Just gut them. Inside one might find a usable transformer. Also you can often leave the power entry module and power switch in place. For cosmetics, measure the fron face and go to www.mmmetals.com where you can order a nice slab of aluminum that will cover the front.

The same shop has buckets of used salvaged heat sinks. You need to be a bit creative to figure out what will work. I have constructed a couple of crude and ugly but effect sinks from a piece of aluminum bar (Home Depot) and bolting a bunch of CPU heatsinks from the surplus shop to it.

[Taligent]

Recycling components is a good, inexpensive way of getting a stockpile of standard components - it's these parts that tend to make up the majority of the cost of DIY electronics projects. Capacitors, IC sockets, transistor mounting hardware, etc, tend to add quickly and are highly priced in small quantities. These days I usually only need to buy specialized IC's (DACs, microcontrollers, etc) and can pick off the rest from the parts shelf.

Amplifiers are an obvious source. Also look around for PC power supplies - these contain, among other useful bits, low ESR caps, iron powder/ferrite cores, fast/ultrafast/schottky power diodes, transistor mounting hardware, and IEC sockets. Switching power supplies in general can be quite useful as parts sources. Computer boards (motherboards, expansion cards) are good sources for logic chips, E/EPROM's, voltage regulators, IC sockets, etc. TVs and VCRs have assortments of capacitors, transistors, diodes, crystals, pots, switches, LEDs, connectors/sockets, voltage regulators, etc. Relays and solenoids are good sources of intact magnet wire. Refridgerator/AC compressors are reasonable vacuum pumps - usually for vacuum bagging fiberglass for speaker/electronics enclosures and vacuum bagging transformers in varnish (or just watching water boil at room temperature...simple pleasures...).

The easiest way to go about this is to ask around for older or dead electronics - as there can often be disposal fees for items with CRTs, many folks will be happy if you take these off their hands. Nearly any piece of electronics has some useful parts in it - just take care to discharge power supply caps before taking things apart.

As far as parts that are truly not worth desoldering - small signal diodes, low power resistors, and ceramic capacitors.

For other sources of parts, check with your local amateur radio community. If a hamfest is held nearby sometime during the year, these are usually wonderful sources of inexpensive, good quality transformers, heatsinks, test equipment, etc.

Good hunting!

-Nikhil

[DIY_Peter]

Thanks Taligent!

I'm really looking forward to building a good amp with mostly recycled parts. Hunting for those parts is half of the fun

[jackinnj]

Originally posted by DocP


Most modern TV's use switch mode power supplies rather than linear ones so they don't have transformers at all that you can use.

Some people go to the dump to deposit, others to withdraw -- here in my suburban piece of New Jersey we have rescued Pilot and Fisher amplifiers from the dump, Altec, Advent and AR speakers.

With respect to TV transformers -- it's the older color sets which have transformers capable of 600 or 700 watts -- you will have problem disposing of the TV CRT unless you are very careful.

As a Physics Lab Rat decades ago, I remember that you always look to improvise with used and surplus parts. In Richard Feynman's biography he spoke at length of the reasons that MIT couldn't cook nuclear materials, but Princeton could -- MIT was so "over-engineered" with new and immaculately engineered geer that the scientists forgot that they were experimenting. At Princeton, the research setup was absolutely and truthfully shocking with bare bulbs, bare wires all over the place. Princeton got the job done.

I admire anyone like Feynman who could have a girlfriend in every college town in the US and Brazil.

[willy]

Peter, I built my first amp completely out of recycled parts. It's about a year old and is still going good. If it's your first amp, and you mess something up, then it don't cost you anything. (and I've messed up plenty) It won't match up to a quality P3A, but it was a good, and cheap way to get me started. I used TVs, computer monitors, VCRs, and old satalite recievers.