Re: Full band transverters for satellite operations?
The uWSDR (Microwave SDR) will not need a transverter, it will provide a transceiever operating at the frequency of interest (144, 422, 1268, 2400 etc). It will cover the whole of each band - i.e. 1240-1300MHz. Full duplex cross-band products such as L/S are planned specifically for satellite use. The hardware is still in development, but progress is being made, and software can be downloaded now and used either in simulator mode or with a Softrock. The hardware should be available long in advance of the next HEO launch.
Detailed system simulations show that the RF performance will be as good as, and hopefully significantly better than, a transverter/IF combination.
More details on the uWSDR website - fell free to join the project if you so desire, any extra help would be appreciated.
uwsdr.berlios.de
regards
Grant G8UBN for the uWSDR team
At 08:59 PM 6/14/2007, Grant Hodgson wrote:
The uWSDR (Microwave SDR) will not need a transverter, it will provide a transceiever operating at the frequency of interest (144, 422, 1268, 2400 etc). It will cover the whole of each band - i.e. 1240-1300MHz. Full duplex cross-band products such as L/S are planned specifically for satellite use. The hardware is still in development, but progress is being made, and software can be downloaded now and used either in simulator mode or with a Softrock. The hardware should be available long in advance of the next HEO launch.
Neat. Hopefully I can look at getting the uWSDR going once I get my HPSDR up and running. Just a comment. Firstly, I notice there are plans for Rx only on 2400 MHz. I should point out that the VK terrestrial weak signal segment is 2403 MHz, so if I was to obtain a 13cm module, I would want Tx and RX on the 2400-2404 MHz segment (Rx for 2401, Tx/Rx for 2403).
I'm also interested how the Ethernet and UDP/IP interface and communications goes. All other SDRs I've seen use a soundcard(ish), USB2 or Firewire interface.
Detailed system simulations show that the RF performance will be as good as, and hopefully significantly better than, a transverter/IF combination.
More details on the uWSDR website - fell free to join the project if you so desire, any extra help would be appreciated.
Looks interesting. I can see my future is SDR for the shack. :) One aspect of ham SDR development so far which I really like is that the various SDRs being designed are using both open hardware and open source software, so there's scope for integrating them all together and mixing and matching the software packages as the end user sees fit. Or one might want to indulge in a little hacking and improve (hopefully! ;) ) the state of the art.
73 de VK3JED http://vkradio.com
Tony Langdon wrote:
Neat. Hopefully I can look at getting the uWSDR going once I get my HPSDR up and running. Just a comment. Firstly, I notice there are plans for Rx only on 2400 MHz.
There might be a cut-down, 2.4GHz-only version, but the only cost savings would be the TX power amplifier (100mW-200mW o/p) on the RF board and maybe the TX D/A converter on the baseband board, which is only a few dollars and might be offset by the fact that it would be a different build. If there is a lot of demand we'll look into the possibility of it but I don't think the cost savings will be significant.
I should point out that the VK
terrestrial weak signal segment is 2403 MHz, so if I was to obtain a 13cm module, I would want Tx and RX on the 2400-2404 MHz segment (Rx for 2401, Tx/Rx for 2403).
The 2.3-2.4GHz amateur band is the most fragmented band that we have; there are at least 6 regional variants that I'm aware of. One of the goals is that we want to cover the whole 2.3-2.45GHz band, and we now have a paper design that will do just that without compromising key parameters such as out-of-band filtering etc. I'm not aware of any other amateur radio product that will cover the whole 150MHz at 13cms.
I'm also interested how the Ethernet and UDP/IP interface and communications goes.
I believe that the transmission of the digitised audio has already been successfully demonstrated over Ethernet using UDP. The use of Ethernet allows for long cable runs enabling the uWSDR to be mounted at the masthead and just running power and CAT5 cable into the shack. No need for lengthy runs of coax.
All other SDRs I've seen use a soundcard(ish),
USB2 or Firewire interface.
The uWSDR approach is similar to that of the HPSDR, i.e. we have designed our own sound card, and after some considerable work we have opted for the same very high performance D/A converter that the HPSDR uses. This way we have absolute control of all the key parameters, and it's also cheaper than buying a Delta-44.
regards
Grant
I find myself kind of curious on the question of whether this will be a more or less economical way of satellite ops than a traditional satellite radio? For the moment I had to sell my gear and will be looking to dive back in about the time the HEO birds launch. I still have my computer, of course, and would love to go the SDR route when I set up again if it's economically feasible for me. 73, Michael, W4HIJ Grant Hodgson wrote:
Tony Langdon wrote:
Neat. Hopefully I can look at getting the uWSDR going once I get my HPSDR up and running. Just a comment. Firstly, I notice there are plans for Rx only on 2400 MHz.
There might be a cut-down, 2.4GHz-only version, but the only cost savings would be the TX power amplifier (100mW-200mW o/p) on the RF board and maybe the TX D/A converter on the baseband board, which is only a few dollars and might be offset by the fact that it would be a different build. If there is a lot of demand we'll look into the possibility of it but I don't think the cost savings will be significant.
I should point out that the VK
terrestrial weak signal segment is 2403 MHz, so if I was to obtain a 13cm module, I would want Tx and RX on the 2400-2404 MHz segment (Rx for 2401, Tx/Rx for 2403).
The 2.3-2.4GHz amateur band is the most fragmented band that we have; there are at least 6 regional variants that I'm aware of. One of the goals is that we want to cover the whole 2.3-2.45GHz band, and we now have a paper design that will do just that without compromising key parameters such as out-of-band filtering etc. I'm not aware of any other amateur radio product that will cover the whole 150MHz at 13cms.
I'm also interested how the Ethernet and UDP/IP interface and communications goes.
I believe that the transmission of the digitised audio has already been successfully demonstrated over Ethernet using UDP. The use of Ethernet allows for long cable runs enabling the uWSDR to be mounted at the masthead and just running power and CAT5 cable into the shack. No need for lengthy runs of coax.
All other SDRs I've seen use a soundcard(ish),
USB2 or Firewire interface.
The uWSDR approach is similar to that of the HPSDR, i.e. we have designed our own sound card, and after some considerable work we have opted for the same very high performance D/A converter that the HPSDR uses. This way we have absolute control of all the key parameters, and it's also cheaper than buying a Delta-44.
regards
Grant
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At 12:24 PM 6/15/2007, Michael Tondee wrote:
I find myself kind of curious on the question of whether this willbe a more or less economical way of satellite ops than a traditional satellite radio? For the moment I had to sell my gear and will be looking to dive back in about the time the HEO birds launch. I still have my computer, of course, and would love to go the SDR route when I set up again if it's economically feasible for me.
Well for me, the decision is a no brainer. The most expensive part of the SDR is the PC, and I can make one or more available through the normal upgrade process here. Also, SDRs tend to be easier to upgrade than traditional radios. No going back to the store to buy a new rig, just download it! :)
73 de VK3JED http://vkradio.com
Tony (and others):
I have had the SDR-IQ (500-Hz to 30-MHz) for 6-months. I continue to discover new aspects of this technology. Because it uses USB-2.0 I/F to the computer bandwidth is not limited by the soundcard A/D limitations. The SDR-IQ receives 190-KHz of spectrum in real-time; this means that a spectral display is this wide.
I have it coupled to a DEMI 144/28 converter for use on 2m eme and this permits me to view the complete eme sub-band of most VHF/UHF bands. As faster A/D's become available SDR bandpass will widen and upper frequency (sampling rate) rise . See my webpage: http://www.kl7uw.com/SDR.htm and paper for CSVHF-2007 (it will be available on my webpage after the conference)
One area of weakness in the SDR world has been lack of operating software. If you are a programmer then the open-architecture allows anything you can dream up. The rest of us have to wait until new software appears. Currently, I am using Spectravue and Winrad which support the SDR-IQ and SDR-14.
Quickly projects like uWSDR will eclipse current SDR's, but for now I am finding the SDR-IQ very usable and affordable (and I get my feet wet on SDR's).
Since 144-MHz has become my standard IF for microwave's it will find good use in my portable mw station (the SDR-IQ is a single pcb 3.75-inches square and powered via the USB port of the laptop). Similarly for my satellite station.
Latest application is joining in the Experimental 500-KHz Group in the USA. With the SDR-IQ I can capture the whole sub-band at once.
At 12:17 PM 6/14/2007, Tony Langdon wrote:
At 08:59 PM 6/14/2007, Grant Hodgson wrote:
The uWSDR (Microwave SDR) will not need a transverter, it will provide a transceiever operating at the frequency of interest (144, 422, 1268, 2400 etc). It will cover the whole of each band - i.e. 1240-1300MHz. Full duplex cross-band products such as L/S are planned specifically for satellite use. The hardware is still in development, but progress is being made, and software can be downloaded now and used either in simulator mode or with a Softrock. The hardware should be available long in advance of the next HEO launch.
Neat. Hopefully I can look at getting the uWSDR going once I get my HPSDR up and running. Just a comment. Firstly, I notice there are plans for Rx only on 2400 MHz. I should point out that the VK terrestrial weak signal segment is 2403 MHz, so if I was to obtain a 13cm module, I would want Tx and RX on the 2400-2404 MHz segment (Rx for 2401, Tx/Rx for 2403).
I'm also interested how the Ethernet and UDP/IP interface and communications goes. All other SDRs I've seen use a soundcard(ish), USB2 or Firewire interface.
Detailed system simulations show that the RF performance will be as good as, and hopefully significantly better than, a transverter/IF combination.
More details on the uWSDR website - fell free to join the project if you so desire, any extra help would be appreciated.
Looks interesting. I can see my future is SDR for the shack. :) One aspect of ham SDR development so far which I really like is that the various SDRs being designed are using both open hardware and open source software, so there's scope for integrating them all together and mixing and matching the software packages as the end user sees fit. Or one might want to indulge in a little hacking and improve (hopefully! ;) ) the state of the art.
73 de VK3JED http://vkradio.com
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa@hotmail.com ======================================
participants (4)
-
Edward Cole -
Grant Hodgson -
Michael Tondee -
Tony Langdon