As said I haven't read any instructions / manual but maybe the figures WSJT7 spits out on the readable copies of Jim may give a clue:
Sync = 9
dB = -2
DT = 0.0
DF = -107
W = 33

73, Rik  ON7YD - OR7T

Quoting Rik Strobbe <[email protected]>:

Hello Gary, Jim,

I just fired up WSJT7 in JT4A mode.
I can see a very fat trace at 503.460 that decodes as "TEST M0BMU" and
a little less fat trace at 503.600 that is probably Gary. But even if
I set the marker on 503.600 (1300Hz audio) I still keep decoding "TEST
M0BMU".
It is my first test with JT4A and I haven't read the instructions /
manual, so it is intuitive use.

73, Rik  ON7YD - OR7T

PS: both signals are clearly audible (Jim is S7)

Quoting Gary - G4WGT <[email protected]>:

LF,

I will be beaconing WSJT JT4A again this evening & I would welcome
any decodes, I have made changes in view of not decoding a reply
last night. I just need to confirm my outgoing signal before
changing Tx operation to CQ calls.

502.300 kHz USB dial frequency. Tx 503.600 kHz on even minutes.

73,

Gary - G4WGT.