Hi Laurence

XDW on 137.7752/137.7756 Khz DFCW dot 90  - Dash High

Dot is being swept from 137.7752 to 137.7755  KHz and back at a rate of 3
sec per "cycle"

In the early days of QRSS I was using an analogue signal generator as a
driver. This was somehow frequency modulated so that the frequency varied up
and down during key down. This had the effect of causing the dots and dashes
on the readout to look like worms - much ridiculed at the time but it made
for a very identifiable signal under marginal conditions.

Peter G3LDO