Orbitronics Regulated Amplifier FA-5657/1

[smilan]

Hi, I'm looking info / schematic of this Orbitronics Mic Preamp Regulated Amplifier FA-5657/1.
What can you tell me about it?

 

[mjrippe]

Military, or Federal Aviation (FA). I think I owned one at some point but it was a long time ago. There are some sites that have docs for this sort of stuff, but it can be hard to sort through as they may be listed as part of a complete system.

 

[smilan]

Thanks, I've been searching the internet for info on this unit and could not find anything useful. Do you remember what should be the supply voltage for it?

 

[mjrippe]

I do not recall. Look for ground and power traces, then find the capacitor that connects them. If it is a 35v cap, then try 24VDC, if it is a 25v cap then try 18VDC, etc. Also check the orientation of the cap - these are early enough that they could be postive ground!

 

[emrr]

A 25V cap in this era can mean 24V supply.

 

[mjrippe]

A 25V cap in this era can mean 24V supply.

That is true, Doug. Although one would hope that FAA/military gear would be spec'ed better.