Used what I had, about probably 1,000 PIV bridge looks from the size of it good for 4 amps. I'm using it for 12 volts at about 2.12 amps. Seems to get a bit warm.
So I sticks my dandy new meat thermometer on it which might not be quite tr aceable to NIST and it says 70C after a couple of hours running. A couple h ours later it is up to around 80C. Maybe we can live at 80C. I checked agai n in a couple hours and it again reads 70C.
Is it possible that the Vf dropped with higher temperature to the point whe re dissipating less brings it into like an equilibrium for lack of a better word ?
Buried under a labirin, labywr, lab --- maze of point to point wiring it is not the easiest thing to change again. Should I ?
What's more, I can't go with Schottkies for example because then it'll burn the tubes too hot. That and a resistor maybe ? (if I can find a place for it) Adding anything is not easy in this cramped thing, in fact its construc tion explains why the people who work in those plants assembling shit like this jump out the windows.
It's a "Houston" MINI 1980. Korean I think or whatever and the guy said the y weren't allowed to use that as a brand name for whatever reason. Output t ubes, I forget but they re pretty much like 6BQ5s in push pull, clips at ar ound 18 watts. One interesting thing is that it has a feedback control and it actually makes a difference.
I have no idea what it's worth but I can probably find someone who'll mortg age their tuner or something for it... It's not mine but I do keep in mind what something is worth before putting a week into it. The last person who worked on this was either the smartest MF in the world or the dumbest. Had the 12 volt winding going to the B+ bridge and the B+ winding hanging out, just waiting for someone to hook it up and poof. And with the thing not fix ed he decided to extend the cable from the PS to the map unit and got that wrong. Pulled the filament supply bridge out and it wasn't even bad, and of course cut the wires too short to reinstall. And pulled the dropping resis tor for the B+ to the preamp and phase splitter stages because it showed si gns of heat I suppose, and of course lost it. The owner said looking it up online he found a picture that showed it to be org org red so 3.3K. Plausib le and I put that in and it works fine.
I'll get my money but I would rather change that bridge now then later. Do I have to worry about it ? If there is doubt I'll find something more suita ble.
Manufacturer ? Schematic ? Parts list ? Never heard of such things. I guess it's do as thou wilt as long as the smoke stays in. To replace it I guess I would need something with a lower Vf because dissipation is dissipation. Say it is dissipating 5 watts, no problem but it is when the temperature is up.
I hope to just put some screws in the thing and ship it but I do not want t o have to work on it again. (read those last eleven words about 50 times)
I would have put this in repair but I think thermal characteristics are mor e engineering questions.