[Boatanchors] Hammarlund Muting

[BLIMPY]

Ray,
           Look at your HQ-170 Schematic.

J-1  the " External Relay"  connections are across the Send Recieve switch.

This allows either the front panel switch or an external Mute Relay to 
Make/Break the Reciever  B+ from the voltage regulator.

To use a Mute relay... leave the reciver Switch in SEND.
and wire the Mute relay for normally closed operation  thus enabling the 
RCVR B+.   On transmit, this relay opens and the antenna relay swaps the 
antenna around, while the reciever is muted.

Perfectly normal.. just dumb nomenclature.
National calls the same two terminals MUTE.

Larry W6WUH
www.goldlabelradio.com
Occidental Radio Workshop