Help identifying cards from broadcast mixer/tape machine

[iampoor1]

I recently picked up a lot of random junk on ebay...and was wondering if anyone might recognize what these are from.

I will go in order from the first picture to the bottom of what information I have.

#1 I believe this is from a gates mixer. Has a Triad a13j transformer.

#2 I believe these are Sparta a15 or a70 microphone preamps. 3 germanium transistors each.

Picture 3, 4, and 5. Okay this is where things get weird. I appear to have 2 full sets of these cards. They are never used and the only identifying information besides a bunch of codes on them is the word "Conrac". Google search turns up nothing.

Picture #6. These all appear to plug into a similar looking backplane. The black box on one of the cards is a nortronics t70-t2 bias oscillator. These are from a tape machine perhaps?

I think these are all spares from a radio station. Anyone have anyou ideas or recognize any of this junk?  ;D

https://imgur.com/gallery/YKsrK

 

[bluebird]

The card in pic 3 looks like a discrete bias oscillator. The other ones could be eq/calibration cards for the tape machine.

Those things look easy to reverse engineer, draw it out and you will know for sure.

The mic pres look like they will sound super cool. Trace those babies out first and post the schematic!

 

[Brian Roth]

Conrac made TV broadcast and industrial CRT monitors.

bri

 

[iampoor1]

The card in pic 3 looks like a discrete bias oscillator. The other ones could be eq/calibration cards for the tape machine.

Those things look easy to reverse engineer, draw it out and you will know for sure.

The mic pres look like they will sound super cool. Trace those babies out first and post the schematic!

Im starting to think the ebay seller might of had no idea what they came from too. Yes I will reverse engineer them and see what it looks like.

I will post those germanium preamp schematics too. Thats specifically why I picked up all this stuff, those input transformers looked too sweet to say no to.

Conrac made TV broadcast and industrial CRT monitors.

bri

Ah! Thank you! These must be from a pretty dang old monitor!