Over the last months i got some lots of e-scrap from old (most likely industrial) sanitary systems (heating/burning), from the looks it appears there is not much gold but a bit and a lot of other good parts like relays/switches (ag/au/pd), mlc (ag/pd), resistors (pt group), tantal caps and some other old fancy stuff.. however, most of these "good parts" i have come across sit on (most likely) BeO based boards, with resistors underneath it.
I also found some preheating systems using resistors mounted on BeO plates connected to the heating system in flow heaters.
One of the plates i came across was cracked from the drill pressure when installed, luckily all the dust was settled over the years (it is what i believe).
Also a reminder to be careful, fresh cracks on these boards could be very harmful and even a calculator could unleash a big problem.. stay safe and earn some :G "!
I also found some preheating systems using resistors mounted on BeO plates connected to the heating system in flow heaters.
One of the plates i came across was cracked from the drill pressure when installed, luckily all the dust was settled over the years (it is what i believe).
Also a reminder to be careful, fresh cracks on these boards could be very harmful and even a calculator could unleash a big problem.. stay safe and earn some :G "!