Re: [digitalradio] PSK on AM and you get two sidebands for diversity
Isn't that a Softrock using SDR-1000 or M0KGK software? Jose, CO2JA Paul L Schmidt, K9PS wrote: For a simple transmitter, how about a sound card mode that uses the sound card in STEREO mode with I and Q components on L and R channels, feeding two balanced modulators, and build a phasing-type exciter to do J2D type emissions? Maybe not quite as simple as AM, DSB, or NBFM, but probably pretty close. A companion receiver could use the same scheme to produce a simple I and Q output to feed to a sound card. And no crystal filters on either one...
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
I wasn't so concerned about whether it's ISB, DSB, or whatever; I was more interested in the comment that it would make the rig easy to build. If a simple rig were built with two balanced modulators from a quadrature RF source (easy to do), using stereo audio with a sound card program designed for quadrature audio components would let you produce whatever kind of signal you wanted to... simple and inexpensive. And the corresponding receiver would also be simple and inexpensive. If you wanted to produce a pair of PSK31 signals separated by, say, 150 Hz, with a pilot carrier between them, it'd simply be a matter of building the appropriate waveforms to make it happen that way. Basically, a cheap software-defined radio, covering a small segment of a single band with a single crystal oscillator. By the way, I just checked part 97 -- ISB is legal (type B emission) within certain guidelines... - ps Walt DuBose wrote: If you place different data on either sideband, its ISB which is illegal or if not now, may be in the near future. However, if detecting either sideband independently does not produce separate data streams, then its not ISB. DSB would only double the information of one sideband so you would want to use the other sideband for more data. The question you have to answer is which is better...doubling, being redundant as with interleaving or sending characters twice or obtaining a greater bit rate or raw throughput. Another consideration is what would the bandwidth be with DSB where two 350 Hz PSK modes were sent? The bandwidth would be 770+ Hz. I think that you would still need a raised cos or filter on the transmit tones as well as a brickwall filter on the received signal. Noticed I said think because I haven't really had time to totally digest the use of DSB but I kinda like the approach. A 100 watt PEP DSB transmitter is so easy to build. Using the FCC-2 oscillator as described in the Feb. QST, and a low level diode balanced modulator and several stages of amplication, you could easily build a 100 watt PEP (50 watts per sideband) transmitter. But the problem is finding an ISB receiver which you would need. Perhaps a direct conversion receiver with a Q/I (?) detector and DSP brickwall filter would work. Walt/K5YFW
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
Don't know... I'll have to do a google search on softrock and see what it is. If that *is* what a softrock is, I may just have to get one to play with :) Jose A. Amador wrote: Isn't that a Softrock using SDR-1000 or M0KGK software? Jose, CO2JA
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
The SoftRock is a kit, very inexpensive, with some neat features and an incredibly talented network of contributors joined together with the primary developer Tony Parks, KB9YIG Here is the SoftRock group: http://groups.yahoo.com/group/softrock40/ doc Paul L Schmidt, K9PS wrote: Don't know... I'll have to do a google search on softrock and see what it is. If that *is* what a softrock is, I may just have to get one to play with :) Jose A. Amador wrote: Isn't that a Softrock using SDR-1000 or M0KGK software? Jose, CO2JA -- Thanks! 73, doc, KD4E ~~ Projects: http://ham-macguyver.bibleseven.com Personal: http://bibleseven.com ~~
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
Paul L Schmidt, K9PS wrote: If you wanted to produce a pair of PSK31 signals separated by, say, 150 Hz, with a pilot carrier between them, it'd simply be a matter of building the appropriate waveforms to make it happen that way. Basically, a cheap software-defined radio, covering a small segment of a single band with a single crystal oscillator. Can you describe this to a RF digital design newbie, please? By the way, I just checked part 97 -- ISB is legal (type B emission) within certain guidelines... Can you clarify this as well? So many different things have been said about the relationship of the regs to this mode. And, if the FCC has indicated an intention to render the mode illegal, or has tightened it too far to permit reasonable experimentation perhaps the list members can join together and ask them to make a change -- and explain why? Merely because a mode may be abused is no reason to make it illegal. There is no reason that the FCC cannot set and strictly enforce reasonable maximums for SSB, AM, ISB, DSB, and digital mode bandwidth - to enforce reasonable sharing of limited spectrum -- leaving the mode selection to the users. FM is no wider than common AM and many overdriven SSB signals heard every day. SSTV and DSSTV as well. Limit them all to a reasonable maximum and set the modes free -- users will vote with their mode-selectors. It has been well documented that certain modes do not play well with others, generally difficult to identify and prone-to-QRM semi-auto and auto digital modes -- the restriction of those to narrow segments of the bands makes good sense. Otherwise, with a reasonable enforcement presence, the rest of the bands may be pretty wide open and all modes permitted. WDYT? -- Thanks! 73, doc, KD4E ~~ Projects: http://ham-macguyver.bibleseven.com Personal: http://bibleseven.com ~~
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
The SoftRock V6.1 two band transceiver is very expensive, it's $32 if you can afford that much I recommend you buy one. ;} What a deal! At 06:19 PM 2/1/2007, you wrote: Don't know... I'll have to do a google search on softrock and see what it is. If that *is* what a softrock is, I may just have to get one to play with :) Jose A. Amador wrote: Isn't that a Softrock using SDR-1000 or M0KGK software? Jose, CO2JA Announce your digital presence via our DX Cluster telnet://cluster.dynalias.org Our other groups: http://groups.yahoo.com/group/dxlist/ http://groups.yahoo.com/group/themixwgroup http://groups.yahoo.com/group/contesting http://groups.yahoo.com/group/wnyar http://groups.yahoo.com/group/Omnibus97 Yahoo! Groups Links Cecil Bayona KD5NWA www.qrpradio.com 'Never argue with an idiot. They drag you down to their level then beat you with experience.'
[digitalradio] PSK on AM and you get two sidebands for diversity
Interesting. Run PSK on AM and you get two sidebands for diversity reception and a pilot carrier. This could make building small PSK rigs easier... Leigh/WA5ZNU What about DSB or NBFM, same result? -- Thanks! 73, doc, KD4E ~~ Projects: http://ham-macguyver.bibleseven.com Personal: http://bibleseven.com ~~
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
For a simple transmitter, how about a sound card mode that uses the sound card in STEREO mode with I and Q components on L and R channels, feeding two balanced modulators, and build a phasing-type exciter to do J2D type emissions? Maybe not quite as simple as AM, DSB, or NBFM, but probably pretty close. A companion receiver could use the same scheme to produce a simple I and Q output to feed to a sound card. And no crystal filters on either one... - ps kd4e wrote: Interesting. Run PSK on AM and you get two sidebands for diversity reception and a pilot carrier. This could make building small PSK rigs easier... Leigh/WA5ZNU What about DSB or NBFM, same result?
Re: [digitalradio] PSK on AM and you get two sidebands for diversity
If you place different data on either sideband, its ISB which is illegal or if not now, may be in the near future. However, if detecting either sideband independently does not produce separate data streams, then its not ISB. DSB would only double the information of one sideband so you would want to use the other sideband for more data. The question you have to answer is which is better...doubling, being redundant as with interleaving or sending characters twice or obtaining a greater bit rate or raw throughput. Another consideration is what would the bandwidth be with DSB where two 350 Hz PSK modes were sent? The bandwidth would be 770+ Hz. I think that you would still need a raised cos or filter on the transmit tones as well as a brickwall filter on the received signal. Noticed I said think because I haven't really had time to totally digest the use of DSB but I kinda like the approach. A 100 watt PEP DSB transmitter is so easy to build. Using the FCC-2 oscillator as described in the Feb. QST, and a low level diode balanced modulator and several stages of amplication, you could easily build a 100 watt PEP (50 watts per sideband) transmitter. But the problem is finding an ISB receiver which you would need. Perhaps a direct conversion receiver with a Q/I (?) detector and DSP brickwall filter would work. Walt/K5YFW Paul L Schmidt, K9PS wrote: For a simple transmitter, how about a sound card mode that uses the sound card in STEREO mode with I and Q components on L and R channels, feeding two balanced modulators, and build a phasing-type exciter to do J2D type emissions? Maybe not quite as simple as AM, DSB, or NBFM, but probably pretty close. A companion receiver could use the same scheme to produce a simple I and Q output to feed to a sound card. And no crystal filters on either one... - ps kd4e wrote: Interesting. Run PSK on AM and you get two sidebands for diversity reception and a pilot carrier. This could make building small PSK rigs easier... Leigh/WA5ZNU What about DSB or NBFM, same result?
