NC0B:
>Is 2 kHz testing some magic number? No, but data taken at less
than 1 kHz becomes rather theoretical. Unless the OEMs really start
cleaning up the key click problem, and reducing phase noise even
more, it is going to be hard to work a 1 uV signal when they
guy 1 kHz away is 70 dB stronger. Key click sidebands and transmitted phase
noise will likely overwhelm the weak signal, even if the receiver is
"perfect".
I agree. It's also very dangerous to focus on
one metric only (e.g. IMDDR3). BDR and Phase Noise can be
just as important, depending on the situation. BDR in the
case of very strong local signals (such as a multiop or
a strong neighbor on the same band) and TX/RX Phase Noise
which becomes the limiting factor for close-in signals
(real world CW signals are much worse than continuous carriers
from the crystal oscillators or 8640Bs used in IMD testing).
As an interesting aside, here are some results
from a fairly sophisticated beam-steering SDR using
4 phased verticals and 4 Softrock receivers versus a
classical rig using Beverages (the former also had
Packet spot assistance whereas the latter did not).
http://lists.contesting.com/pipermail/3830/2008-February/150706.html
http://lists.contesting.com/pipermail/3830/2008-February/150705.html
I still feel the ultimate contest setup may be
a classical rig for ultimate RX performance but using
SDR on its IF output for the bandscope plus Skimmer
software for Packet-like spot generation (technically
not "assisted" unless contest sponsors rule otherwise).
73, Bill W4ZV
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