Jan Simons PA0SIM wrote:
.........
If you would have any ideas as to modifying the ANC-4 I would'nt mind
working with you on this project. But I will leave that one up to you.
.........
Sri, I prefer my Digital Signal Processing route with the two Elecraft
K2 receivers.
DSP makes an ideal phaser. So no need here for a "better" analog one.
And DSP gives me a lot more tricks to reduce interference and noise.
73 es gl de Jan PA0SIM
May I ask what the tricks are?
Of course:
1) With only one receiver and one antenna:
- Noise Reduction and Noise Blanker tricks as you see now implemented
in the new DSP transceivers like the Orion and the SDR1000 (all the DSP
must be in the AGC loop!).
- In DSP it is possible to make very small bandwidth CW filters.
- For better CW readability one can use binaural or panoramic reception.
- DSP makes multi notch filtering possible (SSB)
- In DSP it is possible to realize almost every AGC you can think of.
(a better AGC can improve weak signal reception)
2) with two (or more) antennas and two phase coherent receivers
- In DSP it is possible to realize the ideal phaser.
- An alternative is "effective directivity" by frequency component
selection
see: http://home.plex.nl/~jmsi/Effective%...20by%20DSP.htm
(the audio samples show what is possible with it)
- True Diversity Reception, because both receivers can be made identical.
- Enhanced Stereo Reception can improve readability for CW/SSB signals.
3) and the tricks I dont know yet. I am not a DSP guru.
For example: (Blind) Source Seperation?
see: http://en.wikipedia.org/wiki/Source_separation
Rather complex stuff HI.
Donīt forget that not all DSP in the new tranceivers is well implemented.
Important is to recognize that DSP has a bright future for us.
73 de Jan PA0SIM
I have an SDR-1000, not really excited with the way it works. Especially the
noise blankers. Not sure if its the latest SVN or what but the noise
blankers just dont seem to do the job.
I agree with the filtering though. Its better than many rigs I have heard.
I recently added a roofing filter to an "old" Kenwood 930 and it did make a
difference. I noticed the difference in the CQWW contest that just
completed. One night I used the 930 the other the SDR 1000. Both receivers
seemed to work as well as the other. All was going well until the antenna
quit on me. This my friend is a whole other story. Shortened verticals are
not the answer.
Guess I will call Force 12 in the morning and see what they can offer me for
a 75/80 meter antenna.