Mccurdy AT220 card info needed

[diggy fresh]

Hi,

I was lucky to find a Mccurdy AT220 card in a dumpster ( what are the odds..), but i wasn't able to find any info so far on the net.
i already sent an email to Mccurdy radio, we'll see if they can help.

This is a plugin card with an audio transformer, I'm guessing by hammond, the only markings on the transformers are 58966.
The card has one GE 2n508 germanium transistor and two germanium 2n1925 GE transistor,  and a big To-3 2n1971.


the design looks pretty simple ( one sided board), i could trace it but i lack experience a little to figure the workings of it just by tracing.

Anybody is familiar with these cards? where were they used?  schematic, pinout, any info would be greatly appreciated as i'd like to bring it back to life.

thanks,
John

 

[diggy fresh]

backside

 

[envelope]

Hello John, PM me and I can help you with this microphone amplifier.

Hi,
I was lucky to find a Mccurdy AT220 card in a dumpster ( what are the odds..), but i wasn't able to find any info so far on the net.
i already sent an email to Mccurdy radio, we'll see if they can help.
This is a plugin card with an audio transformer, I'm guessing by hammond, the only markings on the transformers are 58966.
The card has one GE 2n508 germanium transistor and two germanium 2n1925 GE transistor,  and a big To-3 2n1971.
the design looks pretty simple ( one sided board), i could trace it but i lack experience a little to figure the workings of it just by tracing.
Anybody is familiar with these cards? where were they used?  schematic, pinout, any info would be greatly appreciated as i'd like to bring it back to life.
thanks,
John

 

[diggy fresh]

Thanks alot Envelope, pm sent.

 

[punk]

Hi,

this is paired with the AT218 line amp to make a full mic pre. a daven 600 ohm T-pad attenuator in between for volume. I used a Hammond  (mccurdy branded mri 3002) 600 ohm line matching output xformer. I recently racked a pair up. Sounds great but haven't had time to do any serious recording yet with it. pm me for the manuals/schematics

byron

 

[diggy fresh]

amazing info guys!

Very cool Byron!  glad somebody racked these.

Byron, i just pm'd you my email.  If you have the at218  schematic/docs, would be great also, my chances of finding one are slim so i might try to clone it if possible.  very helpfull info.

Btw, anybody knows in what type of consoles these where used? some history on these?  barely any info on these online.
I did get a response from Paul Hudson at Mccurdy Radio, he said he has a 6 page manual with installation notes for 25$.
i will gladly pay it if it offers more info than what Byron has.

thanks