G,
Am 27.09.2013 18:07, schrieb Graham:
Which , if you
take into account , Opera is single tone on/off with app
50% duty cycle , self sync mode
and wspr is a 4 mfsk externally time locked
That doesn't matter at all! A successful detection is all that counts,
not the energy (or average power) needed. If Bob can TX 3 kW WSPR-15,
then the RF energy is 0.75 kWh. With 50% duty cycle it may be 0.375 kWh
but who cares????
For the test to be valid , the wspr carrier level
would of needed to be 50% less that of the Opera system
No.
Transmitting amateur radio stations have a certain transmit antenna
with certain limitations (say 0.1 % efficiency) and they have a PA
giving a certain RF power (say 100 W). This results in a certain ERP.
The goal of the amateur radio station could be to be received/decoded
in a distance as high as possible. It is usually completely
uninteresting if you need 0.1 kWh or 0.2 kWh for a transmission, except
in /p mode using batteries.
>From my point of view the only real advantage of Opera is that you can
use a simple keyed VFO, like in CW. But then some will complain about
the key clicks :-)
73, Stefan
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