01-03-2014, 10:57 PM
About 4 years ago a colleague presented me with an auld audio oscillator that was once a Bell Labs property and is an AT&T product - built by Western Electric.
It was obviously mounted in some rack.
I haven't plugged it in as the input jack is non-standard.
So recently (days ago) I realized I might use an audio oscillator, so today I took it out, pulled the chassis (takes 30 seconds - 4 panel thumbscrews and it is out), marvelled at the built. Like a Sherman tank! Beautiful. No criss-crossing at odd angles - everything is north-south grid.
Well, I realized there are two triple electrolytics I would have to take care of, which is easy - it is not a radio so I would just cut them off and put new ones in.
It even has that "no workie-workie when out of the box" button that disconnects power when the chassis is out.
Inside there is also the schematic glued to the back and laquered over, plus the full BOM.
Then I saw no Earth pin in the sawcket, decided to check the chassis for short to the MAINS prongs....woila! One was grounded. Then it occured to me to look at the schematic. And, oh, crappity-crap! It is a hot chassis oscillator! What is worse, the input plug is symmetrical so there is no way to orient it in only one way.
And it does say in the sch "110V DC or AC".
So.....one way of using it is with its own isolation transformer, not shared with anything else.
But I don't feel like taking a risk...what if I forgot one day it needs an isolation!
So.....there it is, a beautiful generator.....semi-useless.
And this is at the very moment I could use one.
Oh, well. I will buy one I guess.
It was obviously mounted in some rack.
I haven't plugged it in as the input jack is non-standard.
So recently (days ago) I realized I might use an audio oscillator, so today I took it out, pulled the chassis (takes 30 seconds - 4 panel thumbscrews and it is out), marvelled at the built. Like a Sherman tank! Beautiful. No criss-crossing at odd angles - everything is north-south grid.
Well, I realized there are two triple electrolytics I would have to take care of, which is easy - it is not a radio so I would just cut them off and put new ones in.
It even has that "no workie-workie when out of the box" button that disconnects power when the chassis is out.
Inside there is also the schematic glued to the back and laquered over, plus the full BOM.
Then I saw no Earth pin in the sawcket, decided to check the chassis for short to the MAINS prongs....woila! One was grounded. Then it occured to me to look at the schematic. And, oh, crappity-crap! It is a hot chassis oscillator! What is worse, the input plug is symmetrical so there is no way to orient it in only one way.
And it does say in the sch "110V DC or AC".
So.....one way of using it is with its own isolation transformer, not shared with anything else.
But I don't feel like taking a risk...what if I forgot one day it needs an isolation!
So.....there it is, a beautiful generator.....semi-useless.
And this is at the very moment I could use one.
Oh, well. I will buy one I guess.
