Return of "Silicon Valley" electronics flea market

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Rich Feldman
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Return of "Silicon Valley" electronics flea market

Post by Rich Feldman »

After 2-year hiatus, the ham-fest or swap-meet in my area has a date on the calendar: Saturday, April 9, 2022.
http://www.electronicsfleamarket.com/

Traditionally it's held on second Saturdays from March - September.
The organizers, an association of amateur radio clubs, recently posted their first event since 2019.
Probably in Sunnyvale, California, but the exact venue has not been announced yet.
The most recent site, a Fry's Electronics store, is out of business.

I am eager to set up a seller space, and give away or sell cheap many boxes of cool stuff.
Including some NST's and other big-ish transformers.
Will hold back my fusor parts, in case they help me to make a fusor some day.
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Richard Hull
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Re: Return of "Silicon Valley" electronics flea market

Post by Richard Hull »

Likewise here in Virginia and North Carolina. 100% of all the traditional hamfests are scheduled for this year! Great news! Actually, last year, 2021, after May 100% of the hamfests were held. I hope others around the nation will have their hamfests fully restored in 2022.

With the hamfest you actually get to see, hold, feel and perhaps test what you buy. The only drawback, no returns or recourse, but that is totally on you and your decision.

Thanks for moving your post.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

Post by Rich Feldman »

I'm packing the car and charting a course for Sunnyvale tomorrow morning, 6 am to noonish.
All models are wrong; some models are useful. -- George Box
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Richard Hull
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Re: Return of "Silicon Valley" electronics flea market

Post by Richard Hull »

I too will be out this morning in 8 hours for a twice yearly mini hamfest hear in Richmond about 1 mile from my home. Next week it is the big Raleigh, NC hamfest. Up at 5 am for that one and the nearly 3 hour drive. The big Richmond hamfest this year in Feb. was, once, again canx. However, we are assured it will be back after a 3 year lapse next Feb. Lots of VA hamfests the remainder of this year.

Good luck at the Sunnyvale fest.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

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The new venue was shut down right after the one meeting of 2022. After neighbor complaints, and perhaps being too small -- some sellers at tail end of line were turned away.

The series has re-started in 2023 at a new venue, West Valley College in Saratoga, now on second Sundays instead of second Saturdays.
Hours are a bit shorter: entry gate opens for sellers at 7 am instead of predawn darkness.
Primary website is the same as in original post of this thread: https://www.electronicsfleamarket.com/

I got rid of many bulky things there in April and June. Went on July 8 just to browse and visit.
Since this forum now accepts un-necessarily big picture files, which are the smallest I can get from phone camera without using editing tools,
here are some sights. (See also 1402 vacuum pump thread and boat anchor thread.)

Precision analog scales please me, especially multi-turn scales.
20230709_090651.jpg
The familiar SWR scale on panel meter with crossing pointers is echoed in power supply module! Why not draw lines for watts on the scale card?
20230709_092758.jpg
Here's a video signal generator that puts out a fixed test pattern, e.g. for after hours broadcasting. No camera tube. A transparent slide with the image goes in front of a small CRT, and is viewed without focusing by a PMT inside the dark box.
20230709_094457.jpg
This guy's big soldering iron is even bigger than mine. Maybe for sheet metal work? Not old or special; you can probably get a new one at Amazon or Walmart.com.
20230709_094643.jpg
More to follow, unless I get complaints about burdening a forum for fusors.
All models are wrong; some models are useful. -- George Box
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

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This picture shows everything I bought, at total cost of $2.
Mainly a Tungar rectifier, used in battery chargers since before 1920 -- wow, that's more than 100 years ago!
In a quick test at home, the filament has electrical continuity, but drew only 2 amps when driven with 4 volts DC, with no visible glow. I think normal operation would be 10 or more amps at 2 or 2.5 volts AC.
The power resistor is a curio, with fixed tap between 1K and 1.2K sections.
loot_July9.png
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Re: Return of "Silicon Valley" electronics flea market

Post by Richard Hester »

If it's Sundays now I might be able to go. Saturdays were previously verboten, as I have a college radio gig on Friday night that keeps me up until 2AM, and at my advanced state of decrepitude, I need my beauty sleep...
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Re: Return of "Silicon Valley" electronics flea market

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Today was final meeting of 2023. I didn't get a seller space, but visited the usual friends & acquaintances, and acquired a few things.
$10 bought a lux meter (my good one has been missing).
$3 bought an Amperite ballast tube with 3 different filaments, which will be fun to light up, _and_ a gauge dial with markings the color of old radium paint. A Geiger counter at home confirmed that the latter is quite active. Then I washed my hands right away. Tonight I'll see if it's visibly glowing.
20230910_181306.jpg
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Richard Hull
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Re: Return of "Silicon Valley" electronics flea market

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A teachable moment:

That dial should be blistering hot. Perhaps to an ion chamber, many mr/hr. I am surprised the dial was free of its instrument! Not a nice thing to do.

I have got quite a load of daughter products (radon decay) on my bare hands, once. While they will all be gone in 24 hours or so, save for the terribly slow 30 year lead half-life, (not detectable), They are tough to remove as they are atoms and not a powder. Simple washing of my hands reduced it to one half activity. I had to scrub with lava soap and a soft brush 4 more times to get the level down to about 1/20th the original level. I ate dinner with nitrile gloves on. In the morning I detected no radiation above background, for the most part. This is the first and last time this happened to me. I knew about the daughters from radium and was mindful of it. However, U ore is in full equilibrium with radium, (millions and billions of years old) and is thus, a radon emitter, albeit much weaker than a radium painted dial.

I suggest leaving all such gauge and meter faces in the instrument, using the instrument as a pure gamma source through the glass for test purposes.

Oddly, my daughter experience was not from radium dials. It was from safe storage of very hot Uranium rock, (ore). Uranium ore is safe to handle with your bare hands. However store it in a sealed gasketed container, (military ammo can), and upon opening it, be outdoors as all the radon will quickly disperse from within. (no danger there)

However the interior of the box and the ore itself will be covered in daughter products. There are several very rapid decay daughters with intense radiation that are atoms!! Atoms that get into pores of the skin which are tough to remove even with intense washing. 1 billion atoms spread over the hands are invisible! Bare hands groping around in an ammo box rubbing against the interior and pulling out ore can easily read 15,000 cpm. A short soapy hand wash will take them down to 7,000 cpm. Vigorous efforts can take the radiation down to a couple of hundred cpm.

Wear gloves when handling any uranium ore that is safely stored or any stored radium products. What you have done in safe storage is protected your home, office, garage from the hazards of radon and daughters in those spaces! (great!) On the downside, you have made all the stored material and its container loaded with intense radon daughter products, concentrated via storage to absolute equilibrium conditions. (nasty)

Removing stored ore using gloves and leaving both the container and the ore out for 24 hours will make things safe to handle.

Uranium metal and all uranium chemicals are safe as no radon exists within them! The uranium decay path to radium and thus, radon, is a million year journey after the metal and chemicals are refined.

About that dial........spray it with Krylon clear plastic spray. 2-3 coatings. The radium and paint is now locked down. Store it in a thick zip lock bag (6 mil). You now have a great gamma-beta source. I would heavily tape over the zip part to avoid any possible radon leak. That is a great dial and a great find that will serve you well if handled with care as above. I would keep it out of doors in an outbuilding in a leaded container. Stored this way, after about 30 days in the sealed baggie the radiation will grow a good deal over when you packed it up. This is due to the trapped radon daughters in the sealed baggie reaching equilibrium. No need for gloves here in future. (unless you are anally retentive or are just a fraidy cat.)

I often do radon daughter wipe counts with a damp 2" regulation round wipe and place it under my 2" pancake for a count. (done on all bench tops) All good here.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

Post by Rich Feldman »

Thanks for posting the warning about things with radium lume. I'll put the hot dial in a Ziploc and hope to monitor an increase in activity.

The dial was for showing manifold pressure from 10 to 50 inches of mercury.
News popped up today about cleanup of radium at a place in UK, where some remains of scrapped aircraft were dumped after the war.
https://www.bbc.com/news/uk-scotland-ed ... e-66819219
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Richard Hull
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Re: Return of "Silicon Valley" electronics flea market

Post by Richard Hull »

Radium is nothing to play with. Old SEALED aircraft instruments are good sources of safe gamma sources to test ion chambers, gamma ray spectrometers, etc.

By sealed I mean you haven't gone into them or tampered with them in any way. The glass is not cracked or missing. If you find any hole in them front or rear, seal them completely. If you have a naked dial, as above, use the above missive to safely retain the dial in a sealed manner.

Radium is very nasty stuff. Take another look at the dial in the earlier post! If you had all of the radium chemical in that dial, assuming you could isolate it as its chloride, and it was a full 5uCi source, typical for such a large dial, it would be 5 micrograms of contained radium. Invisible as the metal, but as the chemical it would be about the size of a single grain of salt and emit 187,500 count per second or 11,250,000 cpm! You do not want any fraction of that grain of salt in your body, yet it is pretty evenly smeared over all that paint! Again, Nasty stuff.........

https://en.wikipedia.org/wiki/Curie_(unit)

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

Post by Rich Feldman »

Here it comes again! The flea market in Saratoga, California.
2024 season begins on Sunday, March 10, hosted by West Valley Amateur Radio Association.
https://www.electronicsfleamarket.com/

I'll have to miss this one.
All models are wrong; some models are useful. -- George Box
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Dennis P Brown
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Re: Return of "Silicon Valley" electronics flea market

Post by Dennis P Brown »

All too familiar with radon gas - living on the East coast this is a chronic problem for many homes. I, in fact, am even now building a radon removal system for the crawl spaces under my home- ugh. Tight spaces - not fun.
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Rich Feldman
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Re: Return of "Silicon Valley" electronics flea market

Post by Rich Feldman »

Back from overseas adventure in March,
I'm looking forward to April 14 for getting rid of some boat anchors
and cool things I won't have time to play with.
Any fusioneers planning to attend, are welcome to drop me a line before the show.
All models are wrong; some models are useful. -- George Box
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