Post Your Cool Pic Here! / General Chatting / Forums

Forums

4hv.org :: Forums :: General Chatting

« Previous topic | Next topic »

Post Your Cool Pic Here!

first previous 186 187 188 189 next last

Move Thread

LAN_403

MinorityCarrier

Sun Oct 11 2009, 04:51PM

Registered Member #2123 Joined: Sat May 16 2009, 03:10AM
Location: Bend, Oregon
Posts: 312

That stuff reminds me of Micron Technology in Boise, Idaho, who would routinely throw out old Semicon. mfg equipment. A scrap yard in Nampa Idaho, right down the road from where I worked (Zilog) got most of it. I burned out buying all the stuff Micron tossed and sold a bunch back in '02 at a Hamfest in Washington state. Made $1000's.

Nicko

Sun Oct 11 2009, 05:40PM

Registered Member #1334 Joined: Tue Feb 19 2008, 04:37PM
Location: Nr. London, UK
Posts: 615

Not a dumpster-dive, more the wonders of ultrasonic cleaning and a bit of TLC. i.e never give up hope!
Before:

After:

Scott Fusare

Sun Oct 11 2009, 05:45PM

Registered Member #531 Joined: Sat Feb 17 2007, 10:51AM
Location: Burlington, Vermont
Posts: 125

Mads - The "dumpster" is at my place of employment here in Vermont. This was a rare find, pickings are normally not this good.

MinorityCarrier - I know what you mean about scrap overload. Between working for National Semiconductor, then Lam Research and also having access to a scrapyard that had the IBM contract I could have started my own fab

Well, at least the plasma etch sections... Age and constrained space have (mostly) cured me of this disease.

Scott Fusare

Sun Oct 11 2009, 05:50PM

Registered Member #531 Joined: Sat Feb 17 2007, 10:51AM
Location: Burlington, Vermont
Posts: 125

Nick - Stunning job cleaning up those sockets. I don't even see any pitting. Did you re-plate them?

Scott

Nicko

Sun Oct 11 2009, 06:03PM

Registered Member #1334 Joined: Tue Feb 19 2008, 04:37PM
Location: Nr. London, UK
Posts: 615

scott fusare wrote ...

Nick - Stunning job cleaning up those sockets. I don't even see any pitting. Did you re-plate them?

Nope, I used 5 minutes @ 50C in a 3% Tikopur & water solution at 45kHz/100W followed by a good scrub with a toothbrush/interdental-brushes & "Goddards Silver Dip" - a non-abrasive silver cleaner we get in the UK - available in the USA too... If you look, you can see the occasional ding in them...

I like your dumpster dive - very neat! My best

is not so cool (only caps) but useful blocks and lots of them...

Scott Fusare

Sun Oct 11 2009, 06:58PM

Registered Member #531 Joined: Sat Feb 17 2007, 10:51AM
Location: Burlington, Vermont
Posts: 125

An ultrasonic cleaner is something that I lack, but have coveted for years now. Sure did do a nice job for you.

Nice find on the banks of RIFA caps. I miss my local scrapyard, it's been gone for some 15 years now. I don't know were the local high tech goodies get tossed now. I suspect they a hauled out of state.

The 2 B&L stereo scopes will make a wonderful addition to the lab. Having reached that age at which the eyes become traitorous I have been wanting just such a crutch to help with the SMT work.

One wonders if the VTTC crowd has any interest in the 4CX250Bs? I have only seen one coil built with them and that was back in the early 90s.

Steve Conner

Sun Oct 11 2009, 07:27PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Hi Scott,

That looks like a distributed RF amp. It's basically a lumped transmission line with gain instead of loss. I don't see any tuning components, so it's probably broadband, Class-A: an EMC test amplifier or similar. If it were Class-A, it would be very tolerant of mismatch, so would be fun to experiment with. You could hook one end up to a RF generator and the other to the base of a Tesla resonator.

4CX250Bs are too nice to waste in a VTTC. They have way more gain and frequency range than necessary and it's not at all obvious how to use a tetrode in the classic VTTC circuit without burning out one or other of the grids.

The best bet is to sell them to hams and buy some cooking-grade triodes.

Scott Fusare

Sun Oct 11 2009, 08:08PM

Registered Member #531 Joined: Sat Feb 17 2007, 10:51AM
Location: Burlington, Vermont
Posts: 125

Hi Steve

You are spot on about the source of the amplifier bank. It came from a Maxwell Labs pulse amplifier that our EMC lab scrapped out. The rack I rescued was only one of the 3 that it contained. This was also the source of the bank of electrolytics.

I know they are not well suited for VTTCs but they will work and are compact, although for my money they lack the aesthetic appeal of a glass enveloped valve.

As I don't much care for VTTCs myself and have no desire to build a high power VHF amp I will likely part out the rack on Ebay. Would that I had the room for an antenna farm to justify the power at VHF, but I don't.

Dennis Rogers

Sun Oct 11 2009, 11:21PM

Registered Member #1837 Joined: Tue Dec 02 2008, 02:20PM
Location: NYC
Posts: 65

Nice one Scott on page 62! I just picked up a 90 year old Bausch & Lomb microscope off ebay. It's built like a tank and works perfect. It must weigh 20 lbs. They don't make em like they used to.

Scott Fusare

Mon Oct 12 2009, 10:07AM

Registered Member #531 Joined: Sat Feb 17 2007, 10:51AM
Location: Burlington, Vermont
Posts: 125

Lovely scope Dennis, a true thing of beauty!

first previous 186 187 188 189 next last

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob