[GreenKeys] Northern Radio 152/2

[Jim Haynes]

85 Hz shift is standard for carrier telegraph systems up to 75 baud.
Transmitting a bunch of channels on either a voice grade wire line or on
a SSB voice grade radio circuit.

At one time some of the MARS services also required that shift be either
850 or 85, no 170 or other shift allowed.

I've never been able to try 85 Hz for single-channel RTTY, but would
like to.

I don't know anything about 240 Hz shift - maybe that was for higher
telegraph speeds.