K3 Panadapter / SoftRock
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I think this will be really interesting.
Some surplus xtals seem to be available as close as 32,768MHz (8,192). If you have 2 separate RX, why not have 2 SoftRock (cheap) or two input to 1 SoftRock ? Benny OH9NB _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I do not recall having yet seen any mention of digital SSB or other
digitized voice possibilities for the K3. I'll confess to being ignorant of this topic. Perhaps someone can address the possibility or non-possibility of this. Regards, Dick - KA5KKT/4 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On May 16, 2007, at 11:53 AM, Edward Dickinson, III wrote: > I'm not exactly sure we are talking about the same thing. > > http://www.aorusa.com/ard9800.html Yes, we are talking about the same thing. They take the voice and digitize it and then put the data stream into multiple PSK carriers that fill up the entire voice bandwidth (2.7KHz). I would take their claim of, "The digital signals may require LESS SIGNAL than analog throughput making operations possible under adverse band conditions," with a grain of salt as not too long thereafter they say: "Your duty cycle will be more intense. This is important to users of amplifiers. Because the digital signal makes full use of the SSB audio bandwidth, you should consider that you will be transmitting at the maximum power output you have selected. At maximum power settings, this will likely result in your transmitter consuming more power and generating more heat. If you transmit images or large data files, your "key down" time could be three minutes or more." This tells me that they are transmitting with higher average power so of course more power reaches the destination. I think they are counting on a much smaller peak-to-average ratio than SSB so S:N is more consistent. Time to become familiar with the term Eb/No. But this is not really SSB, at least, not as we think of it. They are generating the digital signal at what would be a very low IF (300Hz - 3000Hz). We think of that as being audio but it is really just a very, very low IF. They modulate a number of carriers in that spectrum and then use the SSB transceiver to translate that up to the final RF frequency. The SSB transceiver is being used as a linear translator. PSK31 and AFSK (RTTY) work exactly the same way. 73 de Brian, WB6RQN Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Brian Lloyd wrote:
> Yes, we are talking about the same thing. They take the voice and > digitize it and then put the data stream into multiple PSK carriers that > fill up the entire voice bandwidth (2.7KHz). Ever see a digital TV signal on a spectrum analyzer? A UHF FM group I belong to has a site at Meadow Lakes, CA ... the "Mt. Wilson of Fresno." On the scope, a DTV signal is a rectangle, 6 Mhz wide, and constant envelope. I suspect digital voice is pretty much the same only the rectangle is 2.5Khz wide. 73, Fred K6DGW - Northern California Contest Club - CU in the 2007 CQP Oct 6-7 - www.cqp.org _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Brian Lloyd-6
Keep in mind that the spurs generated will probably [produce a signal that
will exceed the 2.7 Khz bandwidth! Especially with operators who are not that technically inclined. To digitize the signal really won't gain you a whole lot! As more and more people try it, I fear the noise floor will rise with more and more use of it. 73, Sandy W5TVW ----- Original Message ----- From: "Brian Lloyd" <[hidden email]> To: "Edward Dickinson, III" <[hidden email]> Cc: "Elecraft Discussion List" <[hidden email]> Sent: Wednesday, May 16, 2007 5:42 PM Subject: Re: [Elecraft] Digital SSB..? > > On May 16, 2007, at 11:53 AM, Edward Dickinson, III wrote: > >> I'm not exactly sure we are talking about the same thing. >> >> http://www.aorusa.com/ard9800.html > > Yes, we are talking about the same thing. They take the voice and > digitize it and then put the data stream into multiple PSK carriers that > fill up the entire voice bandwidth (2.7KHz). > > I would take their claim of, "The digital signals may require LESS SIGNAL > than analog throughput making operations possible under adverse band > conditions," with a grain of salt as not too long thereafter they say: > > "Your duty cycle will be more intense. This is important to users of > amplifiers. Because the digital signal makes full use of the SSB audio > bandwidth, you should consider that you will be transmitting at the > maximum power output you have selected. At maximum power settings, this > will likely result in your transmitter consuming more power and > generating more heat. If you transmit images or large data files, your > "key down" time could be three minutes or more." > > This tells me that they are transmitting with higher average power so of > course more power reaches the destination. I think they are counting on a > much smaller peak-to-average ratio than SSB so S:N is more consistent. > > Time to become familiar with the term Eb/No. > > But this is not really SSB, at least, not as we think of it. They are > generating the digital signal at what would be a very low IF (300Hz - > 3000Hz). We think of that as being audio but it is really just a very, > very low IF. They modulate a number of carriers in that spectrum and then > use the SSB transceiver to translate that up to the final RF frequency. > The SSB transceiver is being used as a linear translator. PSK31 and AFSK > (RTTY) work exactly the same way. > > 73 de Brian, WB6RQN > Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: > 269.7.1/805 - Release Date: 5/15/2007 10:47 AM > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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On May 16, 2007, at 7:41 PM, Sandy wrote: > Keep in mind that the spurs generated will probably [produce a > signal that will exceed the 2.7 Khz bandwidth! Especially with > operators who are not that technically inclined. To digitize the > signal really won't gain you a whole lot! As more and more people > try it, I fear the noise floor will rise with more and more use of it. You see that all the time on PSK31. The sad thing is that it is so easy to get it right. Usually the problem is nothing more than turning the mic gain up too high and causing splatter. OTOH, if you are doing that you are running your PA and your amplifier (if you have one) at 100% power output with 100% duty cycle. That will tend to be a self-correcting problem as hams destroy their amplifiers and the PAs in their rigs. FWIW: 1. turn off DSP signal processing on receive (no noise reduction); 2. turn off your transmitter speech processing; 3. turn the mic gain down until you are only getting about 30W out (as most 100W rigs are rated at only 40W continuous). Do those three things and you will have good success with the digital modes such as they are today, i.e. sound card in your computer plugged into your K2. 73 de Brian, WB6RQN Brian Lloyd - brian HYPHEN wb6rqn AT lloyd DOT com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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