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
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