Old components - Page 1
Forum section: electronics / beginners

author: moepower
author_rank: Contributor
timestamp: November 05, 2013, 05:53:50 am
content: Hi all,I've recently inherited some old electronics parts. I've attached some pictures of some of the old parts I have. Can anyone see any use or value in the big fat resistors? I've got tons of these. Also, I would please like some help in identifying what the other components are.Thanks a lot.Paul

author: Jebnor
author_rank: Regular Contributor
timestamp: November 05, 2013, 06:09:39 am
content: Inductor? Resistor, Capacitor, capacitor capacitor.They are big, which means they are more difficult to accidentally blow up. Play with them.

author: moepower
author_rank: Contributor
timestamp: November 05, 2013, 06:14:27 am
content: Thanks Jebnor, much appreciated.Will play.

author: Crazy Ape
author_rank: Regular Contributor
timestamp: November 05, 2013, 06:21:35 am
content: 1. Inductor (Perhaps for RF).2. Carbonfilmcomposite resistor.(Edit:Correction.)3. Wire wound resistor.4. Capacitor.5. Electrolytic Capacitor.

author: moepower
author_rank: Contributor
timestamp: November 05, 2013, 06:27:58 am
content: Thanks,Not sure what use I can make of these, considering better parts exist.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 05, 2013, 06:31:47 am
content: 1st Pix ---- Inductors (these ones are what are commonly called RF chokes.)2nd Pix---These are 1/2 watt carbon composite resistors----the LH one looks a bit cooked.3rd Pix--- 5watt wirewound resistors (OK for power & audio work,too inductive for HF)4th Pix---Polystyrene capacitors ----the smaller values like these are good for HF use.5th Pix--Great big,boofy,chassis mount Electrolytic capacitor--mainly used in power supplies.Don't be too quick to write them off--the chokes & Polystyrene caps look like New Old Stock,so are probably as good as,or better than,anything new!

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: November 05, 2013, 06:36:53 am
content: 1) Old axial inductor ('choke'), possibly 2.5mH. Still useful to people experimenting with radio circuits, particularly old tube equipment and such like. Not too useful when building semiconductor radio circuits. No longer manufactured, so could possibly be worth a $ or two each if you have a lot of them.2) Allen Bradley carbon composite resistor, 3.3K. No longer manufactured. Some people still want these for building audio circuits, but they are not hugely valuable, as there are still large stocks out there. $1 each, maybe, if you can find the right buyers, and they want the value(s) you have.3) Glazed porcelain power resistor, wire wound. Looks like 47 ohm,but could be 4.7 ohm. Nearly indestructible power resistor, still very much useful if you need one of these. Infinite shelf life, but the form factor makes them most interesting to people, who are restoring or repairing old equipment.4) High stability polystyrene capacitor, 3.3nF. Used for making very stable radio and audio circuits, particularly oscillators and filters. 3.3nF makes this more of an audio component than something you'd use at radio frequencies. Infinite shelf life, and people still want these for various Hi-Fi applications, if you have the value(s) needed. Note: *Highly* sensitive to overheating when soldering.5) Electrolytic capacitor, junk. No sane person would want these, unless they have a really recent date stamp. Electrolytic caps have a limited shelf life, and if they are 30 years old...The mounting bracket may be worth a few cents, but they are readily available to anybody, who wants some.

author: moepower
author_rank: Contributor
timestamp: November 05, 2013, 07:42:29 am
content: Thanks for the detailed information. Very much appreciated. I'll hang on to themI got these and other stuff from a yard sale. These were in a nice "Rota" metal chest of component drawers that the lady was going to throw out, I didn't ask why. Also scored a lot of computer chips (old 80's or 90's EPROMS, flip flop chips, counters, NAND and NOR gates, 7 seg decoders, de/multiplexers, quartz oscillators, etc.) plus typical R, L, C components new and old, solder, heat shrink and a very nice eye piece magnifier lens.Best yard sale ever.

author: Rascal
author_rank: Contributor
timestamp: November 05, 2013, 09:45:38 am
content: I wouldnt 'write off' the electrolytic capacitors necessarily. I have repaired old tube sets / powers supplies etc and have stocks of these capacitors going back 60+ years - the vast majority can be successfully 'reformed'.

author: ElectroIrradiator
author_rank: Frequent Contributor
timestamp: November 05, 2013, 11:18:07 am
content: Quote from: Rascal on November 05, 2013, 09:45:38 amI would. Restoring a vintage piece of electronics, which may rarely be used after restoration, is one thing. Buying 'NOS' electrolytic capacitors of unknown age and condition, and building them into a new construction, is not worth the risk of setting yourself up for an early failure IMO.When I restore vintage valve gear, which is intended to actually be used on a regular basis, then I unceremoniously replace *all* electrolytic capacitors with new, high quality 105oC components. Whenever possible I do try to leave any large Aluminum encased filter caps in place for the visual impression, but they are not connected.

author: Rascal
author_rank: Contributor
timestamp: November 05, 2013, 03:10:55 pm
content: I would have no hesitation in using an electrolytic that is under 20 years old - this has worked for me successfully with failure rates about equal to that of brand new caps.

author: Zero999
author_rank: Super Contributor
timestamp: November 05, 2013, 03:18:06 pm
content: Quote from: ElectroIrradiator on November 05, 2013, 06:36:53 amCorrected. LOL!

author: Excavatoree
author_rank: Frequent Contributor
timestamp: November 05, 2013, 03:24:00 pm
content: Quote from: Hero999 on November 05, 2013, 03:18:06 pmOne audiofool sight sells carbon composition resistors because they added a "rosy glow around the notes." They also say that "the noise is a non issue," but they point out not to build a mic pre-amp with them.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 06, 2013, 01:59:03 am
content: Quote from: moepower on November 05, 2013, 07:42:29 amWhere are you?The reference to a "Rota" chest suggests Aust or NZ.If so,forget the references to "Allen-Bradley" resistors.they were probably "Morganite" or "IRC".Carbon composites are considerably less inductive than some earlier type film resistors.so be cautious about older "carbon film" types.Noisy?--maybe,but remember these were used in quite high end audio measuring equipment back in the day.Stuff with specs which would still look good.I think that the reaction to "audiophoolery" has gone to the other extreme,with carbon-composite resistors beingcondemned out of hand because idiots make a fuss about them.Harder to destroy?----it's been pretty much my experience,that there is not much between them & film resistors,with the latter being a bit better,if anything.

author: Rory
author_rank: Frequent Contributor
timestamp: November 07, 2013, 03:22:19 am
content: Quote from: vk6zgo on November 06, 2013, 01:59:03 amIn my experience, the old CC resistors tend to contain a lot more smoke than carbon or metal film types.

author: moepower
author_rank: Contributor
timestamp: November 07, 2013, 11:48:16 pm
content: I'm in Melbourne, Australia.Thanks all for the interesting discussion. Even if some of these old parts' reliability may be in question, I'll still use them for prototyping and playing around.Cheers,Paul

author: Rory
author_rank: Frequent Contributor
timestamp: November 08, 2013, 12:24:29 am
content: I would be suspicious of those cc resistors changing value over time. They can absorb moisture from their environment. After all, there are little chunks of charcoal inside. Fortunately it's easy to check.