There is a connection on the rear panel connector that must be made to enable receiving. Part of the transmit/receive system when paired with a transmitter. Maybe the @ relay jumper" you mention. 

I don't remember if it connects B+ to some tubes, or connects some tubes cathode lines to ground. 

I hope it works well for you once you figure it out. 

Roy

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of JAMES FALLS
Sent: Thursday, August 18, 2022 02:14
To: milsurplus; ARC5
Subject: [ARC5] BC-348-R Update

Still dead.

I’m going to pull it from the cabinet again, recheck all the tubes, install the relay jumper,