Guest
Here's one of those old things you just pick up because it's old.
It is a "portable test oscillator". That much is no mystery, but that's about it.
https://dl.dropboxusercontent.com/u/29948706/DSCN0398.jpg
So I dig up a 90 volt power supply, actually by taking an old amp carcass and connecting between the positive and negative rails. A variac got it to the level I wanted. It oscillates, but really doesn't put out anything. I should have put the frequency counter on it but the bench was full up.
V402 is putting out a sine wave. As you can see by the print though, it doesn't go anywhere without some sort of input because V401 is normally in full conduction. On the left is a device they call E402. It appears to be some sort of a cap and waveguide or something like that. I am not taking it apart if I can help it.
The input on the left marker "2" seems like it might accomplish a little bit of frequency modulation, for whatever reason. The input marked "3" would seem to result in amplitude modulation.
It's not a huge mystery how the thing works, but I am puzzled as to its actual purpose. Is it for testing recievers out in the battlefield or something ? Like puts out a steady tone for everyone to tune to with their recievers, something like that ?
I'll probably get some pictures of the whole thing soon in case anyone might recognize it that way. I never thought to take them, I just got one of the schematic which is glued to the inside of the cabinet.
It is a "portable test oscillator". That much is no mystery, but that's about it.
https://dl.dropboxusercontent.com/u/29948706/DSCN0398.jpg
So I dig up a 90 volt power supply, actually by taking an old amp carcass and connecting between the positive and negative rails. A variac got it to the level I wanted. It oscillates, but really doesn't put out anything. I should have put the frequency counter on it but the bench was full up.
V402 is putting out a sine wave. As you can see by the print though, it doesn't go anywhere without some sort of input because V401 is normally in full conduction. On the left is a device they call E402. It appears to be some sort of a cap and waveguide or something like that. I am not taking it apart if I can help it.
The input on the left marker "2" seems like it might accomplish a little bit of frequency modulation, for whatever reason. The input marked "3" would seem to result in amplitude modulation.
It's not a huge mystery how the thing works, but I am puzzled as to its actual purpose. Is it for testing recievers out in the battlefield or something ? Like puts out a steady tone for everyone to tune to with their recievers, something like that ?
I'll probably get some pictures of the whole thing soon in case anyone might recognize it that way. I never thought to take them, I just got one of the schematic which is glued to the inside of the cabinet.