Two 32-bit digital signal processors provide true software-defined
features, along with expansion memory to handle future signal processing
tasks and operating modes. The operator will have full control over any
operating situation, with 8-band receive and transmit EQ, stereo
speaker/soundcard outputs, binaural effects, and advanced noise
reduction. Also included is built-in PSK31, CW, and TTY decode/encode,
so the operator can enjoy the excitement of data communications with or
without a computer. The rig’s rich I/O complement includes an isolated
sound card interface, front/rear mic/phone jacks, dedicated serial I/O,
and band data. An optional module provides transverter in/out and RX
antenna in/out jacks. The latter allow the use of RX-only, in-line
filters for extreme operating environments.
Kevin Alfred Strom wrote:
bpnjensen wrote:
On Jan 14, 4:18 am, dave wrote:
[...]
The K3 has synchronous AM, effortlessly realized in DSP. You need a
base receiver for $1,600, a wide filter for $100 and the General
Coverage filter set. Run you abt $2k.

Is it, by chance, sideband selectable? Or would it be necessary to
use a passband to (more or less) achieve one side or the other?

Thanks,
BJ



I don't know if the K3 uses phasing selectable-sideband synchronous
detection, or if it requires passband tuning to get a similar effect.

But one should greatly prefer the phasing method, since on AM or DSB
signals it gives a 6 dB advantage over using IF filters, because using
the phasing method with a sync detector cancels the _interference_ in
the opposite sideband, but it does _not_ cancel the opposite sideband
energy of the desired signal.

The reason is that the Q detector contains essentially no audio from the
desired signal (the detector's locally generated carrier is locked at 90
degrees difference from the real or imputed transmitted carrier, putting
the desired audio into a deep null), and therefore no cancellation of
any part of the desired signal takes place.

It's too bad the Eton and Sony sync detectors don't provide the option
of listening only to the Q channel output. That would provide the
ability to literally listen to what was underneath any DSB/AM signal.
Some amateur experimenters have done this with homebrew gear, allowing
operation in the close vicinity of 500-kW broadcast invaders of the 40
meter band.

See the article "SSB Q-Channel Communications" for more details:

http://www.antennex.com/preview/Folder01/Nov4/ssb-q.htm


With all good wishes,


Kevin, WB4AAIO.
Two 32-bit digital signal processors provide true software-defined
features, along with expansion memory to handle future signal processing
tasks and operating modes. The operator will have full control over any
operating situation, with 8-band receive and transmit EQ, stereo
speaker/soundcard outputs, binaural effects, and advanced noise
reduction. Also included is built-in PSK31, CW, and TTY decode/encode,
so the operator can enjoy the excitement of data communications with or
without a computer. The rig’s rich I/O complement includes an isolated
sound card interface, front/rear mic/phone jacks, dedicated serial I/O,
and band data. An optional module provides transverter in/out and RX
antenna in/out jacks. The latter allow the use of RX-only, in-line
filters for extreme operating environments.
-eham