6 ms·

Old Heathkits Never Die, They Just Get Restored

90 points by stmw 5y ago

CamperBob2 5y ago
In days past, if you’ve ever experienced an overheated selenium rectifier, you will never forget the unique smell. In this restoration, they all were okay, so I remounted them in the chassis. I replaced the dissected unit with a modern silicon diode. I don't think I would've put those back. The only good thing about the toxic SeO2 vapor they release when they overheat is that it smells so awful that you will probably be in no danger of absorbing a toxic dose. [1] It'd be better to replace them with a 1N400x-diode of the appropriate voltage rating, perhaps with a small series resistor to account for the lower voltage drop in the new part. 1: https://yarchive.net/electr/selenium_rectifiers.html https://yarchive.net/electr/selenium_rectifiers.html
- dtgriscom 5y ago
  A blog post about a selenium compound and its odor: https://www.science.org/content/blog-post/things-i-won-t-work-selenophenol https://www.science.org/content/blog-post/things-i-won-t-wor...
- ananonymoususer 5y ago
  I blew up a few selenium rectifiers when I was a kid, and I distinctly remember the (fart-like) odor. I also played with vaporized mercury, and indiscriminately inhaled lead fumes while soldering. Aside from the chemical contamination, I've also been severely shocked four times (once requiring hospitalization), and received RF burns a few times. No idea what this did to my IQ/personality, but I somehow managed to survive (60 years so far).
  - goldenkey 5y ago
    Not to scare you but a lot of heavy metals and toxic compounds just get squirreled away by the body in some fat or in the liver, appendix, or lymph nodes.
    - GeorgeTirebiter 5y ago
      There are certain substances that 'chelate' those heavy metals. You can get tests that detect the amount of heavy metal in your body (not in your mind -- Metallica will still be lodged in your brain). I think garlic is a natural chelation substance. I learned about this via http://GrossmanWellness.Com/ http://GrossmanWellness.Com/ (not a commercial, just a satisfied patient)
  - GeorgeTirebiter 5y ago
    Have you considered switching from EE to Firmware or Software? (I did almost all the same stuff, but only got shocked once -- on a Heathkit !!!) I now do mostly FW, and use LV on my EE projects.. and I'm still alive !!!
    - ananonymoususer 5y ago
      I actually did switch to software around 1984. All of the above incidents occurred in or before the early 80's.
    - goldenkey 5y ago
      LV meaning low voltage?
      - GeorgeTirebiter 5y ago
        Yes. Sorry.
WalterBright 5y ago
Sadly, I gave away my Heathkit H11. I always got rid of the wrong computers. I had a good time building it. It worked the first try :-)
- GeorgeTirebiter 5y ago
  You can buy H11s on eBay. I have an H11 and H11a + the pair of 8" floppies. I need to 'find the time' to get them running RT. It's a 'well-documented LSI-11' pretty much, I'd say. You should pick one up & restore it! And bring it to VCF (East / West / or wherever they are being held).
  - WalterBright 5y ago
    You can see my former setup here: https://twitter.com/WalterBright https://twitter.com/WalterBright I still have the Heathkit terminal which I built, too. I haven't powered it up in nearly 30 years. At one point I added a 6Mb hard disk drive to it. Built my own interface card, wrote the driver. That made the H11 far, far more usable. But that's gone, too.
phgn 5y ago
Heathkit is the brand name of kits and other electronic products produced and marketed by the Heath Company. The products over the decades have included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, robots, electronic ignition conversion modules for early model cars with point style ignitions, and the influential Heath H-8, H-89, and H-11 hobbyist computers, which were sold in kit form for assembly by the purchaser. https://en.wikipedia.org/wiki/Heathkit https://en.wikipedia.org/wiki/Heathkit
bloopernova 5y ago
That's some gorgeous work, wow. A related story, the restoration of a Heathkit ES-400: https://www.nutsvolts.com/magazine/article/restoring-the-heathkit-es-400-computer https://www.nutsvolts.com/magazine/article/restoring-the-hea...
Syzygies 5y ago
My college stereo amp was a Heathkit. It had one IC, for the phono preamp. My brother built the same amp, and found the leftover IC socket when he finished. Heathkit support was great: "If you didn't toast the IC soldering it in, you'll surely toast it desoldering it just to use the socket. Does the amp work?" It did. My Dad built my high school Heathkit phonograph as I watched. I only understood his caution after he died: I found six years of correspondence with Heathkit before he got his first tube amp working. If you build a car from parts you're dividing the value by four. If you build a loudspeaker from parts you're multiplying the value by four. Follow someone else's well-regarded plans, and get out one-and-done rather than making this a hobby. That's the sweet spot these days for anyone wanting to build their own audio equipment.
- stmw 5y ago
  Six years of correspondence for the first tube amplifier to work -- did you ever learn what the issues were? Or is it that he was just cautious and took his time?
protomyth 5y ago
I remember they had some terminals (H19) that were purchased for a local school because they were cheaper than the local dealer's quote for assembled one (Z19). Not sure what they hooked them up to. It did freak me out that when I became a student at UND, they had rooms of Z19 terminals.
nlh 5y ago
If anyone here is a ham (DE K2KD), you may appreciate that when I first got into amateur radio in the early 90s, a restored Heathkit SB-200 linear amp was like the gold mine of gold mines. It cost about $500 (+ tubes) and would get your “standard” HF rig from 100 watts up to 1200+ watts, which was life-changing. It was about half the cost of modern amps at the time, and I always loved that a solid piece of 1960s engineering remained a staple on the desks of even the most techno-centric hams.
hughrr 5y ago
They do die horrible deaths. Half the Heathkit stuff I have picked up over the years has been utterly irrecoverably buggered by the moron who assembled it to start with or someone who modified it later. Amateur radio kit is the worst variety.
- GeorgeTirebiter 5y ago
  My experience has been exactly the opposite. Because people took pride in their work. Zenith TV had a set of commercials saying "The hand-crafted quality goes in, before the name goes on" -- they hand-built their TVs for a long time after PCBs arrived, and used that fact to sell 'quality'. So 'hand-built' was synonymous with 'quality' for a generation of kit-builders. (Also 'cheapskate' because in those days, electronic kits were cheaper than pre-built units.)
  - hughrr 5y ago
    I think that’s survivor bias. A big chunk of stuff barely worked and didn’t last as long. I had a couple of old and tektronix scopes which are amazingly reliable after 50 years according to the collectors. Nope! Yours are the exceptional ones on the failure bell curve. There are a hundred that were scrapped before you got yours. Mine were asshats.
    - GeorgeTirebiter 5y ago
      Could be. I'll ask around. My Tek scopes (analog vintage anyway) had visited the Tek Shop at least twice. I recently 'restored' two EC-1 Analog Computers. Both were extremely well-built; and in one of them, the caps were even still good (!). My experience is 60s through mid 70s Heathkits. I don't have much experience with 'newer' models. Or older, for that matter. (My first kit was a transistor checker; then a DX-60A. Last kit was probably the mid-range AM/FM receiver/amp. I still have that, and it works great.)
- buescher 5y ago
  Like the posted article, this guy took an SB-101 all the way back down to "kit" and rebuilt it: https://sites.google.com/site/radiow2pa/Home/articles/Heathkit-SB-101-Rebuild-and-Restoration-Notes https://sites.google.com/site/radiow2pa/Home/articles/Heathk... God save us all from the man with the golden screwdriver, though.
fastaguy88 5y ago
I have a Heathkit H8 computer that I built around 1982 that I would love to send to a good home. Probably have manuals, definitely have cassette tape drives used for storage. It’s been sitting in the basement for 38-years and it’s time to move on. Perhaps someone here is connected to a museum or community group that could do more with it. Or point me to a group that would be interested.
- swimfar 5y ago
  You could check with the Computer History Museum in Mountain View, CA. https://computerhistory.org/ https://computerhistory.org/
wly_cdgr 5y ago
"I was pleased with the result" lol, understate much?
buescher 5y ago
Periodically, I wonder if I could be faster on modest simulation problems - think a pair of coupled differential equations - with a small analog computer than I am with Matlab/Simulink. I don't try it, though, because software takes up so much less space.

90 points by stmw 5y ago

In days past, if you’ve ever experienced an overheated selenium rectifier, you will never forget the unique smell. In this restoration, they all were okay, so I remounted them in the chassis. I replaced the dissected unit with a modern silicon diode. I don't think I would've put those back. The only good thing about the toxic SeO2 vapor they release when they overheat is that it smells so awful that you will probably be in no danger of absorbing a toxic dose. [1] It'd be better to replace them with a 1N400x-diode of the appropriate voltage rating, perhaps with a small series resistor to account for the lower voltage drop in the new part. 1: https://yarchive.net/electr/selenium_rectifiers.html https://yarchive.net/electr/selenium_rectifiers.html

dtgriscom 5y ago
A blog post about a selenium compound and its odor: https://www.science.org/content/blog-post/things-i-won-t-work-selenophenol https://www.science.org/content/blog-post/things-i-won-t-wor...
ananonymoususer 5y ago
I blew up a few selenium rectifiers when I was a kid, and I distinctly remember the (fart-like) odor. I also played with vaporized mercury, and indiscriminately inhaled lead fumes while soldering. Aside from the chemical contamination, I've also been severely shocked four times (once requiring hospitalization), and received RF burns a few times. No idea what this did to my IQ/personality, but I somehow managed to survive (60 years so far).
- goldenkey 5y ago
  Not to scare you but a lot of heavy metals and toxic compounds just get squirreled away by the body in some fat or in the liver, appendix, or lymph nodes.
  - GeorgeTirebiter 5y ago
    There are certain substances that 'chelate' those heavy metals. You can get tests that detect the amount of heavy metal in your body (not in your mind -- Metallica will still be lodged in your brain). I think garlic is a natural chelation substance. I learned about this via http://GrossmanWellness.Com/ http://GrossmanWellness.Com/ (not a commercial, just a satisfied patient)
- GeorgeTirebiter 5y ago
  Have you considered switching from EE to Firmware or Software? (I did almost all the same stuff, but only got shocked once -- on a Heathkit !!!) I now do mostly FW, and use LV on my EE projects.. and I'm still alive !!!
  - ananonymoususer 5y ago
    I actually did switch to software around 1984. All of the above incidents occurred in or before the early 80's.
  - goldenkey 5y ago
    LV meaning low voltage?
    - GeorgeTirebiter 5y ago
      Yes. Sorry.

WalterBright 5y ago

Sadly, I gave away my Heathkit H11. I always got rid of the wrong computers. I had a good time building it. It worked the first try :-)

GeorgeTirebiter 5y ago
You can buy H11s on eBay. I have an H11 and H11a + the pair of 8" floppies. I need to 'find the time' to get them running RT. It's a 'well-documented LSI-11' pretty much, I'd say. You should pick one up & restore it! And bring it to VCF (East / West / or wherever they are being held).
- WalterBright 5y ago
  You can see my former setup here: https://twitter.com/WalterBright https://twitter.com/WalterBright I still have the Heathkit terminal which I built, too. I haven't powered it up in nearly 30 years. At one point I added a 6Mb hard disk drive to it. Built my own interface card, wrote the driver. That made the H11 far, far more usable. But that's gone, too.

phgn 5y ago

Heathkit is the brand name of kits and other electronic products produced and marketed by the Heath Company. The products over the decades have included electronic test equipment, high fidelity home audio equipment, television receivers, amateur radio equipment, robots, electronic ignition conversion modules for early model cars with point style ignitions, and the influential Heath H-8, H-89, and H-11 hobbyist computers, which were sold in kit form for assembly by the purchaser. https://en.wikipedia.org/wiki/Heathkit https://en.wikipedia.org/wiki/Heathkit

bloopernova 5y ago

That's some gorgeous work, wow. A related story, the restoration of a Heathkit ES-400: https://www.nutsvolts.com/magazine/article/restoring-the-heathkit-es-400-computer https://www.nutsvolts.com/magazine/article/restoring-the-hea...

Syzygies 5y ago

My college stereo amp was a Heathkit. It had one IC, for the phono preamp. My brother built the same amp, and found the leftover IC socket when he finished. Heathkit support was great: "If you didn't toast the IC soldering it in, you'll surely toast it desoldering it just to use the socket. Does the amp work?" It did. My Dad built my high school Heathkit phonograph as I watched. I only understood his caution after he died: I found six years of correspondence with Heathkit before he got his first tube amp working. If you build a car from parts you're dividing the value by four. If you build a loudspeaker from parts you're multiplying the value by four. Follow someone else's well-regarded plans, and get out one-and-done rather than making this a hobby. That's the sweet spot these days for anyone wanting to build their own audio equipment.

stmw 5y ago
Six years of correspondence for the first tube amplifier to work -- did you ever learn what the issues were? Or is it that he was just cautious and took his time?

protomyth 5y ago

I remember they had some terminals (H19) that were purchased for a local school because they were cheaper than the local dealer's quote for assembled one (Z19). Not sure what they hooked them up to. It did freak me out that when I became a student at UND, they had rooms of Z19 terminals.

nlh 5y ago

If anyone here is a ham (DE K2KD), you may appreciate that when I first got into amateur radio in the early 90s, a restored Heathkit SB-200 linear amp was like the gold mine of gold mines. It cost about $500 (+ tubes) and would get your “standard” HF rig from 100 watts up to 1200+ watts, which was life-changing. It was about half the cost of modern amps at the time, and I always loved that a solid piece of 1960s engineering remained a staple on the desks of even the most techno-centric hams.

hughrr 5y ago

They do die horrible deaths. Half the Heathkit stuff I have picked up over the years has been utterly irrecoverably buggered by the moron who assembled it to start with or someone who modified it later. Amateur radio kit is the worst variety.

GeorgeTirebiter 5y ago
My experience has been exactly the opposite. Because people took pride in their work. Zenith TV had a set of commercials saying "The hand-crafted quality goes in, before the name goes on" -- they hand-built their TVs for a long time after PCBs arrived, and used that fact to sell 'quality'. So 'hand-built' was synonymous with 'quality' for a generation of kit-builders. (Also 'cheapskate' because in those days, electronic kits were cheaper than pre-built units.)
- hughrr 5y ago
  I think that’s survivor bias. A big chunk of stuff barely worked and didn’t last as long. I had a couple of old and tektronix scopes which are amazingly reliable after 50 years according to the collectors. Nope! Yours are the exceptional ones on the failure bell curve. There are a hundred that were scrapped before you got yours. Mine were asshats.
  - GeorgeTirebiter 5y ago
    Could be. I'll ask around. My Tek scopes (analog vintage anyway) had visited the Tek Shop at least twice. I recently 'restored' two EC-1 Analog Computers. Both were extremely well-built; and in one of them, the caps were even still good (!). My experience is 60s through mid 70s Heathkits. I don't have much experience with 'newer' models. Or older, for that matter. (My first kit was a transistor checker; then a DX-60A. Last kit was probably the mid-range AM/FM receiver/amp. I still have that, and it works great.)
buescher 5y ago
Like the posted article, this guy took an SB-101 all the way back down to "kit" and rebuilt it: https://sites.google.com/site/radiow2pa/Home/articles/Heathkit-SB-101-Rebuild-and-Restoration-Notes https://sites.google.com/site/radiow2pa/Home/articles/Heathk... God save us all from the man with the golden screwdriver, though.

fastaguy88 5y ago

I have a Heathkit H8 computer that I built around 1982 that I would love to send to a good home. Probably have manuals, definitely have cassette tape drives used for storage. It’s been sitting in the basement for 38-years and it’s time to move on. Perhaps someone here is connected to a museum or community group that could do more with it. Or point me to a group that would be interested.

swimfar 5y ago
You could check with the Computer History Museum in Mountain View, CA. https://computerhistory.org/ https://computerhistory.org/

wly_cdgr 5y ago

"I was pleased with the result" lol, understate much?

buescher 5y ago

Periodically, I wonder if I could be faster on modest simulation problems - think a pair of coupled differential equations - with a small analog computer than I am with Matlab/Simulink. I don't try it, though, because software takes up so much less space.