Fusor Forums

Slim pickings, but still interesting. I finally had an opportunity to attend the legendary M.I.T. Flea Market, held monthly during the “warm” months in the Albany Street parking garage. Today was the first of this year’s series. A lot of stuff changed hands, but for my interests, it was a bit of a disappointment. The Raleigh Hamfest flea market was bigger. I came away with a couple of small pressure gauges for $1 each, and a big water cooled heat sink made for large semiconductor modules ($5). I was expecting a lot more current vintage high tech stuff. It was quite cold for someone from SC, and the lighting in the garage is pretty poor. As shown in the photo, knowledgeable regulars come with a flashlight. If I was local, I’d still attend each month, but I didn’t find it worth traveling to attend.

I was just over there are the M.I.T. Flea Market as well, yes, it had pretty slim pickings. It probably has a bigger turn out in the summer.

I have a friend who lives in Boston. Not to rain on any parades, but he says that the event is a shadow of its former self.

This is not to say there might not be a super killer deal awaiting the regular attendee who lives there. As the weather gets warmer keep reports coming on this event.

Most places have such events, (hamfests), only once each year. Thus, folks have time to store up, acquire, and resell more goodies in any geographic location.

Richard Hull

Stretching a bit to be fusor related, but I just scored a jewelers micro torch at the Porte des Vanves Saturday flea market in Paris for 20 Euro. It’s mostly antiques and some old tools, but I scored a German watchmakers lathe here a couple of years ago. One of my other interests is miniature books and fine bookbinding in miniature. I found some miniature books, a leather decorating tool, and a set of slightly corroded 8 point brass type for embossing letters in leather (for 15 Euro). I just saw a new set yesterday that they priced at 900 Euro! If you’re ever in Paris on a Saturday, it’s worth the subway ride. I think this one is much more interesting than the huge permanent “flea market” tourist attraction on the north edge of town.

A really nice old air-gas torch of yesteryear. Great find!

Richard Hull

Does it count as "sharing hamfest booty" if a lot of the pictures above are of stuff I sold you guys hahaha

Glad my new old stuff has found a new home. Especially the light stack and those CF's. They needed a good home.

Cheers!

The light stack has a new home on our system rack. It glows red when the HV is on. I haven’t found a use for the green and yellow lights yet, but they still look nice.

Looks great! Glad I could help

Today's (May 20) turnout MIT Flea Market was much bigger than last months, with easily 4x the number of sellers. There were tables all the way up to the top of the parking garage. I got a 22" new in box LCD display for $60 and two 1sccm mass flow controllers for $10 ea.

My haul Pictures of the MIT Flea Market

Hamfests will help fill and supplement a true builder's junk box for future and current projects. My next big one is the Manassas fest in early June. I will both sell and hunt there. Always a good fest. It is usually hot and a hat and a canteen of water is nice to have. By 1PM, the shootin' match is just about shut down and all of the best stuff is already back at the homes of the early bird buyers who left the fest by 10AM. After 1PM, you are looking at vultures rooting through trash cans for loot discarded by folk who left, ditching stuff that did not sell, and worthless, penny-less, tire kickers handling your stuff and chatting you up about it, even though they don't have the money to buy.

Richard Hull

I just visited the legendary Silicon Valley Electronics Flea Market in Fry’s parking lot in Sunnyvale. Compared to the season’s first MIT flea market, I would have to rate this one much better (although Andrew reported that the second MIT Flea had a much better turnout than the first one that I attended). The lighting here is also much better! I scored a few finds: some miniature connector coax patch cables for $1 each, a bag full of ISO flange claw clamps for $3, one 20K/100W resistor for $1 (after digging through many boxes of high wattage but very low resistance ones), and some small center drills (not in the photo). Not a big haul, but It was great fun rooting through boxes of high tech bric-a-brac. I saw a couple of high vacuum bellows valves, but they had been exposed to some very nasty stuff and were quite corroded inside. There was a fair amount of stainless gas plumbing and components (mostly VCR connectors) likely from the semiconductor industry. If I lived in the Bay Area, I’d definitely attend this one every month.

I was there too! I got an oscilloscope for $20.

Alas, the large Manassas hamfest was a bust. Rained all day here and there, too. We were scheduled to leave at 6AM, but it was pouring and so, we bagged it. Mother nature, she owns it, big time.

Great stuff from the other fests above in this post. We often see a lot of vacuum stuff from scrapped fab lines.

Richard Hull

The electronics flea market in Sunnyvale (formerly Cupertino), CA ended its 2018 season today. Alas, demands of my day job left no time to pack up for selling. Double alas, I went anyway, and fell into binge mode. Brought home many things that are small and inexpensive, or small and free.

Here are a couple of uncommon instruments, seen and left on the table: .
Out of pocket cost was about $25 or $30, in exchange for all the items in this picture: The item to save first, in case of fire, is the DC KOLOVOLTS meter. Not an easy thing to find. Or to want.
The 150 volts AC panel meter is ready to connect -- no external components needed. Most of the other meters were free.

New new lab supplies include large and medium clip leads, a DMM, and a handful of wires with pin receptacles on one end. The bundle of stranded wires with pins on both ends ("for Arduino plugboard") actually came from a garage sale on my way home.

The lamp collection now has a 100-200-300W three-way bulb with mogul base; 175 and 250 W gas discharge lamps with clear globes, and a self-ballasting mercury vapor black light bulb. All in their boxes, altogether $6, from three different vendors. One old rectifier tube that came with a loose cap, an unfamiliar JAN number, and no trace of mercury that I can see. One plain photocathode tube (free).

Then red and a near-infrared optical filters, a pair of 55-volt 315-watt toaster elements (NIB, $1), a needle valve with micrometer screw ($1), and a weird little free tube (spark gap?). The big ticket item, amounting to $3 or $4, is the hand-picked assortment of 2W composition resistors in megohm values and one 100 ohm power resistor (actually sought, and put into service today). Rounding out the bundle is a pair of unused AC capacitors full of Pyranol ($1) and a stepper switch whose relay coils operate an escapement mechanism to turn a toothed wheel ($1).

Here's a closer view of the valve and the funny tube-like thing. The latter has a pin terminal on one end and a pinched-off metal tube on the other. What is it?

Nice valve! I paid more like 30 for mine!

The tiny tube looks like a spark gap tube or a HV gas regulator tube.
The smallest meter looks like a radium laced face and needle job from a WWII comm item used in aircraft. Can't see it all that well.
The large loose capped rectifier could be an 866A but JAN numbered for WWII or Korea.
The nupro valve was the real buy. Looks like swagelok connections.

Richard Hull

Yes yes & yes.
I was picky about the free meters, and at least one looked like it had radium paint.
Haven't tried lighting up the funny little diode.
The valve does have those face-seal connectors, including a metal dent protector under one of the plastic dust caps.

The rectifier says JAN-249? (probable remnant of a fourth digit). Filament seems to heat properly on 2.50 volts AC. I let that run for 15 minutes before applying any plate bias. Then it wouldn't light below 19.7 volts DC (measured from one end of the filament), but finally displayed its mercury content. Here with three different photo exposures; current was about 500 mA for the first two. I have no mogul socket that contacts ring terminal of the three-way bulb. In a regular mogul socket the 200W filament works. The other filament has an appropriate DC resistance.

I foolishly expected the self-ballasting mercury vapor lamp to have a coil or something inside. Nope, just a series incandescent filament. Will be interesting to monitor the current as the Hg capsule warms up. If power is interrupted while hot, it need time to cool down before it can restrike on 120 V. Of course the outer bulb, with black light filter, gets pretty hot for a non-halogen incandescent lamp. Yes, Dennis, I wore good sunglasses during that exercise. Probably should have for the rectifier work, but that device is not an intentional radiator of UV light.

The Internet hasn't satisfied my curiosity about whether some discipline really uses a unit called kolovolt.

The official "arc drop" on Mercury vapor rectifiers is typically 13-20 volts. Officially, in college back in 1964 we had to spit out 13.6 volts when giving Mercury arc drop answers on tests.

Richard Hull