RE: Ampliphone HV FAQ is done!!!

> I agree with you completely Clay, but the original FAQ was to go
> through the trouble of *adding* an insulator to an already
> uninsulated, working, 7824 regulator.
>
Oh. :-) Show's you how much I know about Amplifone's...

> To belabor your "unexperienced" point, it seems less likely a
> first-year technician would do any damage by doing "nothing" (if it
> works, don't fix it) than by adding an insulator.
>
I misunderstood the problem. I was offering up an explanation for what
sounded like a vestigal insulator from the original equipment manufacturer.
Kinda pointless if the FAQ has you adding it...

> Make sure you get your caps and
> diodes pointing the right way, and make sure you place the insulator
> on the reg that needs it. Not really all that difficult for someone
> undertaking the recommendations of this FAQ, considering the other
> tasks called for.
>
If the FAQ is for hot-rodding the Amplifone it might be worth a mention to
replace those rubbery-fabric insulators that Atari was fond of for a while
with something with a better coefficient of heat transfer. Even good-old
mica+heatsink grease is pretty good. Most of those "dry" heatsink materials
that claim all sorts of super-high heat transfer efficiencies never seem to
work very well in the "real world", IMHO. Low-tech silicone grease is
pretty good, although messy.

> I don't believe Michael's original intent was to "make things simple",
> but was to "make things a best as they can be", which is the only
> reason I brought up the insulator in an, email to him, in the first
> place.
>
I understand. I'm still a bit of the opinion that it might no be a bad idea
to insulate them both and use liberal amounts of silicone grease. Not that
it *does* anything on the 7824, but people tend to buy and sell machines and
when the next owner decides the "fix it up" and sees one with insulator and
one without they might be tempted to remove (or simply forgot to put back
on) the "important" insulator... Plus, people like symmetry. :-)

(I'm guilty of such a screw-up from working on a car amp a couple years ago.
It had a couple MOSFETs or something where one was insulated and the other
wasn't. The insulator was looking pretty cooked so I removed the heatsink
and cleaned both MOSFETs and heatsink with alcohol really well. I got
interrupted by something and came back to the job a few days later. I
couldn't really see where the old insulator went anymore, but I *knew* is
was the one of the right... Of course I was wrong and let the magic smoke
out when I powered it up. *grrrrr*. Sure, it's a "don't do that" error, but
if they both had heatsinks I wouldn't have had enough rope to hang myself...
;-)

On the other hand, no-matter how much idiot-proofing there is, there'll
always be a better idiot somewhere...

-Clay
Received on Mon Jun 7 17:11:33 1999