Service my Philips 212 Turntable - Part 2: initial measurements

RE: Service my Philips 212 Turntable - Part 2: initial measurements

dang74 — Sun, 09 Apr 2023 15:58:35 GMT

I enjoyed this blog. It's always interesting to see how things were designed 40 years ago. The BJT did a lot more of the 'heavy lifting' back in the day. Today of course we hear about capacitive touch sensing in the context of touch screens. It was interesting to see it here for the speed control.

RE: Service my Philips 212 Turntable - Part 2: initial measurements

colporteur — Fri, 17 Sep 2021 21:22:17 GMT

Enjoyed the presentation. I trust the jenga tower base iss temporary or your going to need a supply of needles everytime it drops. Can you purchase needles? Oh and throw out the vinyl you were playing.

RE: Service my Philips 212 Turntable - Part 2: initial measurements

neptunium — Fri, 17 Sep 2021 13:25:56 GMT

Great article! I also have a 212 in need of some care, so I've been studying the schematic as well. Two of the indicator bulbs are burned out and the auto-shutoff one is probably dead too. I may replace them with LEDs and series-parallel resistor arrangements to keep the same load. Philips actually did that in a later model so I think they would approve.

But what greatly puzzles me is why the designers have used positive ground in this system. Is there any inherent advantage to doing so compared to the ubiquitous negative ground? I've read that on older cars with a positive ground chassis it was done because it allegedly provided a better spark and less galvanic corrosion, but that doesn't apply here. The schematic feels very "upside-down" in places! [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7bba9b51-fbd7-405d-8e4a-ba93f1fe0970/1145.contentimage_5F00_1.png:16:16]

Another oddity is the use of germanium transistors in the power supply. I'm guessing this was done for efficiency/dissipation reasons because of the lower voltage drop?

RE: Service my Philips 212 Turntable - Part 2: initial measurements

Jan Cumps — Thu, 20 May 2021 07:57:24 GMT

Not everyone appreciates a repair.

[View:/resized-image/__size/620x267/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7bba9b51-fbd7-405d-8e4a-ba93f1fe0970/8750.contentimage_5F00_206978.jpg:620:267]

RE: Service my Philips 212 Turntable - Part 2: initial measurements

loriv — Sun, 13 Dec 2020 02:17:17 GMT

Hi! I have this exact same turntable, which my parents bought when they were in their twenties. I'd love to have it refurbished. I live in the Portland area. Does anyone here know someone who might be able to do this work?

RE: Service my Philips 212 Turntable - Part 2: initial measurements

DAB — Mon, 06 Apr 2020 17:40:14 GMT

Very useful Jan, Thanks.

DAB

RE: Service my Philips 212 Turntable - Part 2: initial measurements

memyselfandi — Mon, 06 Apr 2020 10:10:19 GMT

Great job, Jan - I have truly enjoyed reading your write-up! And I like your musical taste as to use "Don't go" from Yazoo for testing [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-7bba9b51-fbd7-405d-8e4a-ba93f1fe0970/contentimage_5F00_28294.png:16:16]

Cheers,

M.

RE: Service my Philips 212 Turntable - Part 2: initial measurements

genebren — Sun, 05 Apr 2020 21:04:33 GMT

Jan,

What a great job of restoring this turntable. That was quite a bit of creative work, hunting down the issues and solving them. Well done!

Gene

RE: Service my Philips 212 Turntable - Part 2: initial measurements

jw0752 — Sun, 05 Apr 2020 19:54:08 GMT

Hi Jan,

Great Compromise on working under the table. Reminds me of putting the car up on a hoist.

John

RE: Service my Philips 212 Turntable - Part 2: initial measurements

three-phase — Sun, 05 Apr 2020 18:18:35 GMT

A very interesting blog to read and great to see the turntable operating - it has been a long long time since I have seen one in someones house.

Kind regards

RE: Service my Philips 212 Turntable - Part 2: initial measurements

Jan Cumps — Sun, 05 Apr 2020 15:36:53 GMT

~ The End ~

[View:https://www.youtube.com/watch?v=FfgWZI_IG7E:740:466]