Steve:

Starting in October I would like to do some serious listening towards Eu

on

LF. Which signals (commercial broadcast) would stand the best chance of
being heard?

and from Geri, DK8KW (W1KW)

you might want to try to listen to the commercial transmitter DCF39 in
Magdeburg on 138.830 kHz (see http://www.qru.de/dcf39-beacon.html for
details).

This is without any doubt the signal to look for.  This signal has a very
unique characteristic even when the signal is extremely weak visually, just
a sliver wide trace of a line on the display you can see even at this level
a "bloom" as the signal goes into an FSK burst of transmission.  By a
"bloom" I mean a very short broadening of the signal spectrum, it is
absolutely unique.  Non of the Loran C or Power Company carrier and spurious
noise signals from the Power Company signals have this single
characteristic.  I have been able to see DCF39 all day long, even in July
and August this year and positively ID the signal by these tiny randomly
spaced "blooms" on the signal line.  This signal also has a very impressive
frequency stability, I am able to hold the signal in a single DFT line for
hours on end.  I also observe here that if you see the DFT line move (about
9 out of 10 times), down one DFT line, there will be an announcement of a
solar flare from IPS in Australia a short time later.  I now have secondary
processing ability here to go look at the DFT data I am collecting during
receive sessions.

For daytime reception of DCF39 I regularly use ARGO at the longest bit
setting possible and also I am now using the DSP56K Box I have here.

Have you started or have ready a transmitting antenna yet Steve?

Good Luck, you will hear this signal over the winter I am sure of that.

Larry
VA3LK