On 25 Jun 2014 at 21:55, Alan Melia wrote:
> 
> It is interesting that there does seem to be a suggestion that 137
> holds up better in summer than 472.......have I read that correctly,
> or maybe it was from another poster. I was not able to do the same
> sort of tests for 472.


I haven't done any scientific tests, but from a lot of monitoring it 
seems that for daytime ranges around 500-1000km 136kHz works better 
than 472kHz. I presume this because the 136kHz daytime propagation 
over this distance is primarily by ground wave, whereas on 472kHz the 
ground wave range is less so sky-wave is needed and this is not 
available until dusk.

It is difficult to compare the two bands over longer distances 
because 472kHz is not available in Russia (unlike 136kHz), and 
activity seems low in many other countries.

Personally, I have been disappointed by the amount of DX received
 during darkness hours on 472kHz so far. It seems commonplace
 to receive stations out to Scandinavia and Italy, but little beyond.
 Yes, I have seen some transatlantic DX but nothing to match 
the stories of worldwide openings reported by retired marine 500kHz 
operators, or indeed what is availalable routinely on 160m. Is this 
just lack of activity?

de Mike, G3XDV
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