[Milsurplus] R388 audio output

[telegrapher at q.com]

I wonder if any of the old comm guys on here might have an idea of what kind of output line level the 388 etc receivers might have been set for?  I'm suspecting that it was only used for rtty audio but don't know.  Was it a -10 or higher on the meter?  Course i know there are variables  but was that a procedure or document or whatever that said to set it for "this" level under average condx and thinking that it ws feeding a 500-600 ohm line.

Larry
W0OGH