Stefan Schäfer wrote:
Mni tnx
Rik for your
answer!
No, you didn’t
spoil the fun at all ;-)
I have
some remarks/ideas.
The coil losses
increase linear with the power but not more than linear. So, 10x the
power
wouldn’t decrease the antenna efficiency (if no arcing occurs, of
course). If we assume an antenna, e.g. in 8m height with many toploads,
then
the efficiency will be poor but the capacitance will be high and thus
the
needed L will be small. Therefore we get a low voltage even with very
high
power and due to the low efficiency we will keep the legal limit. So,
if one
has no possibility to increase the antenna height QRO is one choice,
especially
when the operator is already in pension and cannot do a qso in
qrss10000000000000000000000000 any more ;-)
Dear Stefan, LF group
I did read all the answers within the topic you've started or ,
being more precise, how to get the 1 watt of permitted ERP limit
using different ideas concerning antennae, TX power, "gain" due to
different modulations ( qrss , FEC related, etc...) Of course, in
practical terms an appropriate mixture of all the factors mentioned
along with propagation paths and its duration , results in an ability
of a given station to make a qso
As we all have also some fun with that issue, especially looking at
the qrss1//endless repetition of zeros// so let us make this fun
to stay a little longer..
There was one conclusion: bad antenna - go for a QRO - i would go
for another extreme .. "good" antenna - go for a QRP
the lambda for 137 kHz is, say, 2200 meters, its quarter 550 meters so
why not making a GP ( ground plane antenna) :)
Assuming 3db loss of a GP wrt dipole to get 1 watt erp we must have a
tiny 2 Watt transmitter and.. hire a helicopter for an hour or so
to rise that 550 meters of wire and stay in a suspension mode while ,
at this time , one can make tens of qso using normal CW ( i did not
mention about lambda/4 counterpoises )
when reading about kiloWatts of TX power, corona effects already
compared to Northern lights i immediately thought about the
'opposite' :)
73 de Piotr, sq7mpj
qth: Lodz/jo91rs/
p.s . Does anyone know the cost of a helicopter rental ? ( i mean,
in practice, statistical average or so)
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