A few points:

Since its early days, amateur radio has been a broad pasture.  Before the 
Second World War the RSGB had two main sections: Experimenters, and Transmitter 
& Relay (T&R), which reflected some of the diversity of the hobby.  The Irish 
government still describes amateur radio licensees as "Experimenters".

Mal is, and should be, free to pursue the aspects of amateur radio that 
interest him, and I look forward to congratulating him when he achieves DXCC on 
136 kHz.  However, I suggest he does not have a moral entitlement to denigrate 
the activities of those who wish to conduct what my UK licence describes as 
"technical investigations".  I think he is also in error in suggesting that the 
600 m allocation is part of the amateur service.  Permits have been issued in 
several countries (sadly not yet in France) for people to conduct experiments 
in this part of the spectrum.  A similar situation exists regarding the 60 m 
permits issued in the UK - but in both cases, although the recipients of the 
permits are radio amateurs, the frequencies in question are not allocated to 
the amateur service. 

As to the suggestion that it has all been done before, I would point out that 
the information that is now of interest may either never have been recorded, or 
got lost.  When I first became interested in LF, I searched the technical 
library at BTRL for anything that might be of interest.  I found relatively 
little, and nothing recent.  What there was mostly dealt with the mature 
technology of high power land stations with large antennas.  This is a totally 
different scenario from the average experimenter's situation and it is very 
much to the credit of the latter that much of their work is published in 
widely-available places.

Other services can benefit from the results of our experiments.  For example, 
it became evident some years ago that a new cave radio design was required as 
the existing widely-used one (the Molefone) was no longer manufactured and the 
rescue organisations could see problems looming.  What was finally settled on 
was based on an HF SSB transceiver by John Hey, G3TDZ.  Field tests on the 
prototype were carried out, above and below ground, by amateurs holding permits 
for 73 kHz, before finalising the design for the cave radio frequency of 87 kHz.

To sum up, by all means plough your own furrow, but let others plough theirs 
and remember: we have to justify our presence on the band.

73
John Rabson 
Radio F5VLF
58800 Cervon
France
JN17vg