Quirky Tek TM506 power frame

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Feb Tue 11, 2020 10:43 pm
Mechanicville NY 12118 USA

Quirky Tek TM506 power frame

Post by ArtFromNY »

Needed to put a pair of PS503A power supplies in it that use to live in a 503, which does not have a high power slot - I wanted to be able to draw 600ma or so out of one of them, so put it in slot 6, the high power one. All good. Pulled a function generator out of slot 5, put the second, known good, PS503 in and it promptly blew one of its fuses. Shrugged it off, changed the fuse, same thing. Pulled it out, took the 503 out of the high power slot and put it in slot 5, fuse blew.

Ok, I figured that each slot has a regulator output transistor and slot 5's was bad. Changed the fuses again in the 503s, put one is slot 4, one in slot 6, both worked fine. Put one in slots 1,2,3 and it worked fine there too. Put a DMM in slot 5, as expected, it worked fine. Took it out, put a PS501 in there, worked fine. That was odd, but I guess if I pull the manual I will find that the 501 does not use that external regulator transistor. Haven't got time or need to fix slot 5 so I labeled it rather than change the transistor.

Shook me up a bit; had I gotten an offer on the 506 I would have sold it as 100% working; I never gave thought to the fact that some plugins want that transistor and others don't; I checked the 506 when I got it by just populating it with an assortment of plugins - function generators, meters, an op amp, a few power supplies, I even stuck a scope in there, and all worked well. I remembered to make sure I had a module in the high power slot that could take advantage of it, and it worked.

Had me scratching my head for a while, so I figured I would share and maybe make things a bit quicker for someone whose frame kept knocking out certain power supplies.
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Barry H Bennett
Nov Wed 30, 2016 6:35 pm
Sunbury, Ohio 43074

Re: Quirky Tek TM506 power frame

Post by Barry H Bennett »

Another thing about the TM5xx series frames is that they are all customizable, and some have had "work done" to them for a specific setup of modules. So, when selling one or even buying one, always expect the unexpected with these things. They were quite versatile and flexible in their day.... still are actually. I use a few myself :mrgreen:

I do have one with a blown slot that I have not looked into, and one with a bad frame supply that i may part out lol. Sorry Art I forgot. I'll check now

Working on parts of these can be a real exercise in remembering where each of 100 different screws and nuts go. "Some disassembly required". I guess TEK figured they would never need any work :)
Preserving the hist. of electronics, one boat anchor at a time! :)
Nov Wed 15, 2006 6:56 am
35216 Biedenkopf, germany

Re: Quirky Tek TM506 power frame

Post by MM »

yes :-)
actually I am also working in that:

DM501 no A , need a new front frame and the knob,
DM504A get a plexi including the mask for the 12 LED
The frame is a TM 503

Very nice to have the A502 , what can be compared to a 1A7A, useful as preamplifier.
The low cost chine scope FNIRSI is somewhat nice but the sensitivity of the inputs is not funny, connected to the preamp it wakes up to very useful thing.

.. and a 250MHz Pulse Generator, delivers rectangle @50Ohms.
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