Philips GM2315/1 Sinewave Generator 1957 tube repair

[@a.m.bal.4191]

When Philips made excellent products. God bless.

[@alainblazit9504]

I used it when I was at engineering school.

[@splitprissm9339]

Love these placards with the tube names, like in a botanical garden or museum. Unfortunate, though, when they turn into gravestones. 5:51 wait a moment, so if the capacitor blows up in your face, you get an extra dose of cooking solder with it? :)

[@splitprissm9339]

18:00 ah, the famous wax capacitor test - if they make a sound when you drop them on the bench, they are leaky :)

[@_GunWi_]

The EZ80 is also a "normal" Tube, it is just a Rimlock tube. The powercord is wrong connected, you are right: Red was earth. This Philips is really nice, I have some from this time in my collection, but not this one 🙂

[@TeardownOZ2CPU]

i need to focus on getting my rimlock tube collection a bit up, so i go look more for this at the next fleamarkedes.

[@_GunWi_]

@@TeardownOZ2CPU Okay, hopefully you don't buy the one I want to buy 😂 Good luck!

[@ivanpopovic9503]

Noval have 9 pins. Not 8.

[@TeardownOZ2CPU]

EXACTLY, funny i said all that compleetly wrong, I dont recall beeing drunk, I have changed the subs in that section of the video, so it will be more correct :-) thanks a lot for the comment

[@ludmilascoles1195]

And I thought HP instruments where over engineered 😅😅😅 I bet it was that blob of solder you removed, was a most likely a balast counter weight 😂

[@splitprissm9339]

Probably the simpler version of the famous Tektronix silver solder spool :)

[@itsonlyme9938]

How about fitting silicon rectifier diodes and then some gas regulator tubes ? OA2 and a OB105 and it will give you 255 volts.

[@splitprissm9339]

I find gas regulator tubes a bit scary ... if they are worn out and don't strike reliably, you get spurious overvoltages ... and running any equipment with gas regulators in it up on a variac ends up producing the opposite of the intended soft start :)

[@TeardownOZ2CPU]

@@splitprissm9339 YES gas regulators also scare me for exactly that reason, but history has shown us, in most cases, they out live all other parts in the unit, if i alone look in the tube lot i have to throw out, it is almost never a regulator tube.

[@splitprissm9339]

@@TeardownOZ2CPU The parts that regularly outlive all other parts might be the parts that regularly destroy everything else :) I tried out a little bias power supply device made in the 1960s based on a gas regulator... it is simply too scary to use the instrument. They essentially shunt regulated 300 something volts down to 70 with the gas regulator and some voltage dividers and a big pot across the presumed 70V. Tubes might just not mind suddently being biased with some minus 80 volts when there is a hiccup with the gas regulator. I do though.... Add to that various possible failure modes of old potentiometers....

[@TeardownOZ2CPU]

@@splitprissm9339 exactly, and rarely any type of over / under voltage protection in the design, so when simple things brake, the result is so much extra go away also..

[@splitprissm9339]

...Don't most rimlock tubes have a noval or miniature near equivalent, probably the base of the dead tube could even be used to make an adapter (if you can chop it off in one piece)?

[@TeardownOZ2CPU]

yes near equvilant tubes exist, in most likely noval socket types, i need to make a little configurable adapter series :-)