Hexadecimal Display Source/MIT Swapfest Advice - Page 1
Forum section: electronics / projects

author: Infrared_Fred
author_rank: Regular Contributor
timestamp: February 08, 2021, 09:05:19 pm
content: Does anyone know of any common vintage electronics that would have used TIL311s or other hexadecimal displays? In a few moths I am hoping to go to the MIT swapfest i.e. old electronics flea market and I would like to possibly pickup some test equipment to repair or teardown if it is not easily repairable(I have a small electronics bench but only a $50 multimeter and semi-eccentric component collection breadboard, etc). In doing so I would love to get some hexadecimal or at least "smart" LED displays, but I would vastly prefer not to have to get them from ebay or other online shopping type of idea. Also if anyone has any advice on shopping at the swapfest (stuff to get/avoid, etc.) or suggestions of bring a multimeter or whatever, I have never been there before and I am a relative newbie in electronics in terms of projects.Thank you!

author: PaulAm
author_rank: Frequent Contributor
timestamp: February 08, 2021, 10:06:15 pm
content: Are they really going to be running it? Hard to believe large public events would be held before widespread vaccination takes place.Generally speaking, buy what you need. If you buy components because they look interesting, they''ll sit on your shelf until you end up pawning them off on some other unsuspecting soul.I like to look for test equipment, soldering equipment and interesting parts. A number of times I've spend $20 admin + $50 in gas to go to a swap and walked away with $5 of heatshrinkIf you don't have much on your bench, look for equipment to expand it. Try to test it out before buying though. Easy to end up with a door stop.I did get a nice 3ph VFD at the MIT flea years ago when you could still haul those onto a plane in carryon.

author: wizard69
author_rank: Super Contributor
timestamp: February 09, 2021, 01:44:24 am
content: Quote from: Infrared_Fred on February 08, 2021, 09:05:19 pmYou will need a very compact meter or you will get tired of carrying it around!Discipline is the key word when talking about swap meets, as it is easy to waste money on "deals". Often the deals are not that real and amount to people making money off junk that should have been recycled. If you go, make sure your have a goal or goals as to what you might pick up.As to that DMM you are carrying around don't think that it will tell you if an instrument is good or bad. In fact anything used is by definition less than factory perfect. Even if somebody is trying to sell you their latest recapped project it is still a used piece of equipment and will fail or have problems just like all used equipment.For "new" electronics some of the best bets are people selling off partial pick and place reels of hardware from a long ago project. Even the stuff that drops out of the machines at setup time is worth considering.Tools can often show up at such meets. The trick here is recognizing a quality tool from junk. I'm talking both power tools and hand tools here. For example small drill presses can show up, but the stamped sheet metal Chinese drill presses are not normally worth the asking price. Some stuff is worth repairing others things are not. When it comes to hand tools, generally you are better off buying quality new tools, unless you get real lucky.Much the same can be said about electronic instrumentation. Some is great even if you have to repair and other instruments probably should go in the trash! Electronics is especially bad in this case because you often can not get parts. Contrast this to new bearings for a drill press which you can get for 100 year old equipment fine. You really need to decide if doing restorations is your thing and if the cost is justified.Bring a third party along to dampen your cabin fever and keep your buying in check.

author: CaptDon
author_rank: Super Contributor
timestamp: February 09, 2021, 03:50:04 pm
content: Amateur Radio Hamfests are much the same. Got royally screwed a few times, but I got the last laugh a few times!! Bought a Tektronix TM504 with an FG504 function generator, a DC502 frequency counter and a DM502 multimeter. Paid $100.00 and he swore everything worked great!! The TM504 had a shorted pass transistor on the negative supply in one slot and every module had damage to the negative supply components. Spent two Saturdays doing repairs and all works great!!! The FG504 alone is worth about 3 times what I paid for the whole mess!!! There is/was a Lithuanian guy that used to be a vendor at the fests. EVERYTHING he sold was broken/damaged/missing parts or simply non-functional and he represented everything as 100% WORKING. People got wise to this huckster!!! When we would see someone about to make a purchase we would lean in and say "You better assume it is broken" or "You'll be sorry, buy somewhere else". I got some great deals at the fests also, got a complete Pace desoldering station with spare parts at the Gaithersburg Hamfest for $50.00 in perfect condition!! At the time it was probably worth $200.00 In some cases like estate sales where the kids were selling off 'Dads Stuff' and didn't know what the 'stuff' was I actually gave them a bit more than the asking price since it was worth it to me and often helped the kids with burial/funeral costs and such. I hate the low-ballers that try to get you way down in price and you know they are going to flip it on Ebay. If I suspect this is the case (let's say it's worth $100.00 and I'm asking $65.00) I simply tell them "It is worth at least $100 and I'm asking $65 but for YOU just for today I'll take $70. I'm glad to see them walk away as I would rather sell my stuff to someone who will use it and appreciate that he/she got a good deal on a nice fully functional piece of equipment!!!