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-   -   A quick Philips PM3217 oscilloscope restoration (https://www.vintage-radio.net/forum/showthread.php?t=127596)

MrBungle 26th Jun 2016 4:24 pm

A quick Philips PM3217 oscilloscope restoration
 
2 Attachment(s)
Possibly not as vintage as some things on here, but I managed to obtain a 1981 Philips PM3217 for a very respectable 10 this morning. This was actually the same model as the first oscilloscope I owned in 1991. As advertised it was like this:

Attachment 126614

Good Sunday project. Spent a couple of hours on it cleaning it up. Turned out to have two problems with it otherwise it was entirely working. The A attenuator knob's internal bush had detached from the knob body due to wear. This was fixed quickly with some 5 minute epoxy and is as solid as all the other ones. The second problem was the B attenuator's coupling switches were dirty. Some careful repetitive prodding appears to have cured this at least in the short term - I have ordered two replacement switches anyway. That, a good clean and polish and there is a good outcome. Everything works, including trigger holdoff and delay timebase, triggering is rock solid and it seems to still be in calibration against a separate 10.000 voltage and 10.000MHz frequency references.

Attachment 126616

This will probably end up as my daily driver scope due to the nostalgic value is has for me.

mhennessy 26th Jun 2016 4:43 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
Lovely 'scopes. That's one of the later models, in '80s brown/beige. Funny how the earlier blue/grey ones seem less dated today...

What's nice about working on these is how the whole front panel assembly comes out in one bit lump. You start by removing the CRT knobs, as those potentiometers stay behind, but everything else comes out together. Various connectors unplug from the main PCB en route. Having done that, access to all switches, etc, is really easy.

One cosmetic problem we've had is the plastic CRT bezel going brittle with age, so it falls off if you move it around. Otherwise, these have proved to be extremely reliable and easy to use. I like them a lot :thumbsup:

MrBungle 26th Jun 2016 5:07 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
I haven't actually seen one of the older ones. If I'm honest, after a few years of staring at 80s Marconi kit you get a warm fuzzy feeling when you see brown test gear :)

I havent dismantled this one fully yet so I look forward to that experience. Considerably nicer than getting at the timebase on a Tek 465b I imagine!

Bezel on this is actually rock solid still fortunately. The original one I had suffered from the falling off problem which was resolved with blue tak wedged in the recesses. Probably not the best thing for the job but it worked.

mhennessy 26th Jun 2016 5:22 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
2 Attachment(s)
A couple of pictures - the first showing the original colour scheme, and the second showing how the front panel assembly separates. Quite a lot of screws to undo and connectors to unplug, but the instructions in the manual are pretty good...

MrBungle 26th Jun 2016 6:38 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
Thanks for posting this. Looks much nicer in blue! Rather impressed with the industrial design on this actually. As good as an HP 1740.

mhennessy 26th Jun 2016 10:49 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
About 5 or 6 years ago I fixed numerous faults in a 1740, only to be left with what I think is a duff hybrid module in the vertical channel. Must dig it out and have another look at it. Though I've no idea what I'd use it for, having since bought that 100MHz Philips/Fluke Combiscope you can see in the background. That's a lovely bit of gear but has a very noisy cooling fan. Not looking forward to having to fix that in the future though ;)

Anyway, nice job on your 3217. Let me know if you ever need any help with it in the future, as I know them fairly well...

MrBungle 27th Jun 2016 8:10 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
Yuck. I really don't like hybrid modules. Same problem with Tek 400/7000 series. The attenuators have thick film hybrid modules in them that like to go pop when someone abuses the front end. These are pretty extortionate to get hold of individually. Cheaper to buy a parts mule and steal the bits than buy spares.

Also don't like fans which makes me like this oscilloscope.

May take you up on that offer - fingers crossed it will remain working nicely. Many thanks! :)

Nymrod121 28th Jun 2016 3:20 pm

Re: A quick Philips PM3217 oscilloscope restoration
 
A great way to spend a Sunday ... and a very worthwhile result too :)
Cheers
Guy


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