On Wed, 05 Sep 2012 01:53:54 -0400, Kevin Alfred Strom
wrote:

*On 9/5/2012 1:13 AM, Arid ace wrote:
* On Tue, 04 Sep 2012 14:10:53 -0400, Kevin Alfred Strom
* wrote:
*
* *Here's a 10 MB mp3 audio file I recorded with the SDR-1000 last
* *night of some ESSB operators on 3630 kHz.
* *
* *It's amazing what excellent sound some of these experimenters are
* *getting out of single sideband. For years -- decades really -- only
* *(highly modified to broadcast standards) AM gear was getting this
* *kind of audio quality on amateur radio. But improved techniques have
* *really made SSB sound better than ever!
* *
* *For best results, listen on a high fidelity set of speakers or
* *headphones:
* *
* *
http://liberty.3950.net/W9AD-KU8R-K9...%20Hz%20bw.mp3
* *
* *
* *73,
* *
* *
* *Kevin, WB4AIO.
*
* That sounds absolutely great, the intelligibility increases much more than
the
* static. Thanks for posting this, it's all I need as an incentive to exchange
my
* Dutch licence for a Panamanian one and get active again.
*
* Jan (ex-PA0DGL)
*
*
*
*Great, Jan; glad it inspired you to get back on the air. I always
*liked good audio on amateur radio -- it allows subtlety of meaning
*and expression and personality to come through -- and disliked the
*pinched, distorted sound that was the SSB norm for a long time.

I didn't like the sound of SSB pressed through a 2.3 KHz bandpass filter either
Kevin. With 3 KHz it was somewhat acceptable if your design cut the lower
200 Hz so the audio was from 200...3200 Hz.

*
*Once I get the transmit side of my station set up (I am building the
*audio and control interface now and I need to put up a good transmit
*antenna) I will be back on the air for the first time since 2000.

With SDR an entirely new field has been opened up and AM modes could sound
better than ever before. When the synchronous demodulation module is written as
a subroutine, it can be active simultaneously on adjacent channels, calculate
the interference caused on the channel listened to, and eliminate it. Long ago
the issue was how to realize that in hardware (complicated and mostly
theoretical) but in software it's perfectly doable now. Similar treatment for
other types of interference. So a great opportunity to revive the AM modes.

*
*Hope to work you someday. Guess I'll have to put up a good low-angle
*radiator!
*
*
*73,
*
*
*Kevin, WB4AIO.

The 80 meter longwire in my garden gives S9 + 40 dB for many US ham operators
but the QRN is too high for comfort so I'll have to experiment with separate RX
antennas (loops, small horizontal dipoles etc.) to minimize that. But once it's
solved, I'll build a 6 KHz SSB TX and adapt a receiver for it. No doubt we'll
have QSO.

73s,
Jan