Very well said.
On 01-Jan-15 2:21 AM, Markus Vester wrote:
As announced before,
the German longwave broadcast transmissions on 153 and 207 kHz
(Deutschlandfunk) and 177 kHz (Deutschlandradio) will be
terminated with the New Year 2015. Presumably mediumwave AM
transmissions will follow one year later. It has been claimed
that the continuation would be too costly, considering the
relatively small number of AM listeners.
Along with others, I think that
this is a sad landmark in radio history, because
- AM radio is simple and
intuitive. The concepts of AM transmission and reception are
easy to conceive, even by a child. And it's motivating to play
with it. In a few years, the kids can still build a diode
receiver, but listening to the small surrogate oscillator
Daddy has hidden behind the sofa will surely not be the same
thing!
Then try to explain digital audio
broadcasting to your grandson, all the way from end-to-end
(microphone to speaker. I even have strong doubts that there
is a single expert person now who understands the whole chain.
Every engineer is supposed to be working on the details of a
small subpart, knows little more than he "needs to know", and
communication is done by formal processes and requirement
specifications. Of course this is a general trend in
industry, but I don't think it is very desirable.
- AM is linear. Listening to 153 kHz in the evening
hours, faint Algerian music can be heard in the background.
When I was young I was fascinated by those distant sounds, and
it probably contributed strongly to my later interest in "DX".
You can actually hear that the radio waves have come a long
way, experience selective fading, and solar effects, or subtle
ionospheric effects like Luxembourg crossmodulation. Modern
digital radio considers all this undesirable interference -
what you get is either perfect mp3 stereo, or nothing at all.
- AM is a historic legacy.
Especially on longwave, each transmitter and antenna coupler
is a unique installation, and the antennas are impressive
monuments. SAQ is a good example: While it's no longer needed
for transatlantic communication, it's still being kept alive
as an educative and fascinating world heritage. Why not keep
at least one large LF broadcast transmitter?
- LF and MF radio is efficient.
The half-megawatt Donebach transmitter probably consumes a
million Euros worth of energy per year, and in addition, there
is antenna and transmitter maintenance to be paid for. But it
provides gapless service across many million square
kilometers. Similar coverage with DAB will probably require a
thousand or more digital transmitters, which in total may well
consume a higher amount of power and secondary costs. One
difficulty about keeping LF transmitters alive may actually be
there are so few of them - as most engineers seem to
be working on software and silicon chip-level hardware, it may
become hard to make spare parts and find experienced service
people for high-voltage RF in the future.
- Radio helps to protect against
spectrum pollution. Members of the LF group are only too aware
of the inflation of inadequately filtered SMPS power supplies,
"dirty" ADSL and PLC communication over unshielded copper
lines, and upcoming threats like inductive e-car charging
devices. Currently there are still EMC regulations in place
which at least provide some limit on radiated and conducted
interference above 150 kHz. But when there are no more AM
broadcast listeners, why should anyone invest effort to
protect that part of spectrum against local interference? The
situation for those few crazy LF enthusiasts who enjoy digging
down to the noise floor may soon become comparable to that of
backyard astronomers in an urban environment - ie plain
frustrating.
End of rant...
Anyway, all the best for the new
year,
Markus (DF6NM)
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