14 Jan
2006
14 Jan
'06
1:58 a.m.
On Sat, 14 Jan 2006 01:15:07 -0500
"Richard A. Cini" <rcini at optonline.net> wrote:
Interestingly, there is no fuse holder at that
location (bridged with a
jumper). Instead, there is a standard 1-1/4" glass fuse holder in the back
panel. Certain spots of the power supply board I've glued-over with
insulating plastic (salvaged from the HV section of various power supplies
over the years).
Very bad design indeed. The pads at the top are very close to the metal cage
and the HV traces on the power supply board are uninsulated.
The worst high voltage design I have ever seen was a Fluke
Digital Voltmeter that I used to have. I think it was an 8300.
It used Nixie displays, and the high voltage for the Nixie tubes
ran on a trace that just weaved it's way across the circuit board
(with feedthroughs, etc,) without isolation or anything about it
to differentiate it from other traces. The board was not
solder-masked, so the metal was bare and exposed. Adjacent
tracks were low-level signal lines.
Granted, it was a high-end precision DMM so nobody was supposed
to go inside except the high-priest calibration dude, but
still....
Does anybody else here appreciate old Fluke gear? My newest
piece is an 8060 DMM, which is late-70's 4-1/2 digit meter. What
I really like are the Fluke Differential voltmeters. I currently
have a nice 881AB. The John Fluke Company made their name with
Differential Voltmeters and high-end lab-grade meters. (I'm
biased against anything in a Fluke DMM without a 4-digit model
no., the 8060 is the best handheld they ever made, the newer
'autorange' lines have always been a disappointment to me.)