On 10/15/20 3:41 PM, Josh Dersch via cctalk wrote: > On Sun, Oct 11, 2020 at 8:13 PM jim stephens via cctalk < > [email protected]> wrote: > >> I agree. Most devices are expected to be heated briefly to soldering >> temperatures, not heat soaked at that. >> >> Temperature in this case is much different than heat. The designers of >> the devices must take into account what temperature is require to do the >> solder assembly function, and minimize the amount of heat the device is >> exposed to. >> >> On wave soldering machines the heat was quite low, and these would have >> been assembled then. Even with current radiant oven techniques, the >> parts would fall off if there was an extended heat exposure. They do >> that often enough now with heating problems with devices, with open >> circuit failures happening. >> >> If you're lucky and have a quick fire department response, the setup >> time on the equipment is at least 4 or 5 minutes. Unless there's >> physical danger and the building involved may have people trapped, they >> take time to assess the fire, the propagation and there's more time >> before they attack. >> >> I've seen a couple of events and a couple of full exercises, it doesn't >> happen quickly. Fire departments are sadly known for letting buildings >> burn into the basement if it saves life or property of other nearby >> structures. You'd be lucky to get this out of a burned out building in >> most cases. Once the fire is knocked down the heat will be present for >> quite some time afterwards, as they let it cool and clear flash fires, >> and take care of nearby property. >> >> thanks >> jim >> > > Well, we'll see how bad these things really are. The idiot I am, I struck > what I consider to be a reasonable deal for the 11/70 and 11/45 and I'll be > picking them up in November on a trip to SF I already had planned. What > can I say, I'm a glutton for punishment. > > A friend of mine went out and ot a number of decent high-res pictures of > the units. The backplanes/wirewrap don't appear to be physically damaged, > and the boards inside look pretty decent, though I'm not holding my > breath. (I was particularly surprised that none of the pot-metal card > stiffeners were warped or bent due to the heat, even near the front on the > 11/45 where it's clear most of the heat was present.) I do have a friend > with a spare set of 11/70 boards. What sold me though was that the 11/70 > has a PEP70 + Hypercache board set installed (which would be really cool, > assuming anything in there can be made to work again). > > I figure worst case, I get a couple of DEC racks that'll work fine after > some sanding and repainting, and maybe I can send the chassis off to Ethan > if repair turns out to be impossible. > > - Josh Awesome news that someone is going to try to salvage the machines!
Best of luck! --tom
