Hi Alan,
about the frequency is really few hertz below 135.800 KHZ.
About timing also here is little annoing to stay for all the cicle to
receive the 3 power levels, the message may be changed in this way:

IK2DED/B  LF BEACON JN55FO  2 or 3 times at 7 wpm full power
then qrss
IK2DED/B JN55FO PWR HIGH  PWR MED  PWR LOW
then restart in normal cw

In this way all the 3 power levels will be on the screen more or less
alltogheter, beacouse the first part of message will be at 40 W, the "PWR
MED" will be at 4 W, and "PWR LOW" will be at 0.4 W.

Here at my home with a little ferrite antenna followed with the preampl
described in setpember column of RADCOM LF page, i receive all 3 the power
level in aural CW, but i'm very near to the beacon, about 20 KM far.
So the lower power level is really useful also here to check different type
of receiving antenna.

73 and thanks for wrote, Giulio Scaroni IK2DED.

Hi Giulio, I have a trace from  2330z to about 0245z at about 135.797, the
signal seems to be subject to quite a lot of fading, so there are periods
when the signal is not really copiable even at the 40w level. But I also
have traces of almost 15 minutes length where the signal is easily seen.
This should cover a complete power cycle. There do not seem to be gaps

where

the low power level QRSS3 should be, so maybe even the low level was

copied

on peaks of the fades. I really need to measure the timings more

accurately

and work out how long each QRSS3 transmission would have been.  This is
using ARGO in 10 sec mode and slow display.....it was done this way to

have

a comparison of the stepped power levels all on screen at the same time.

Cheers de Alan G3NYK