Hi!
I have been using SDR receivers as part of my satellite work for a little while now, and have used (or tried to use) a few of them...
"RTL-SDR" dongles (the $20 or so dongles) FUNcube Dongle Pro (original version) FUNcube Dongle Pro+ (current version) SDRplay HackRF (One and Blue versions)
The RTL-type dongles and the FUNcube Dongle Pro (not the Pro+) lack front-end filtering, which rendered them useless when I tried to transmit with either an HT or FT-817 in close proximity - even with there was a diplexer in front of the SDR devices. These devices would basically shut down until I ended my transmissions, when they would resume working. The newer R820T2 type of the RTL dongles may have better stability, but they all seem to lack front-end filtering that would be desired when working our satellites.
The FUNcube Dongle Pro+ and SDRplay work well as the downlink receiver when I have worked satellites. These devices cost more than the RTL-SDR dongles, but they come with front-end filtering that helps greatly when they operate near your uplink transmitter. I have had success with both of these devices, along with HDSDR (the Windows software I prefer to use when working satellites with SDR receivers) running on a laptop or small Windows 8.1/10 tablet. I currently prefer to use the SDRplay as my downlink receiver when I am working satellites, but will occasionally use the FUNcube Dongle Pro+ from time to time. The SDRplay currently retails at US$ 149 from either HRO stores or the www.sdrplay.com web site located in the UK. The FUNcube Dongle Pro+ costs around US$ 190 to US$ 200 including FedEx shipping from the UK, depending on the exchange rate.
The FUNcube Dongle Pro+ is supported by the FUNcube Dashboard software for FUNcube satellites like AO-73, and the FoxTelem software for AO-85 and the upcoming Fox-1 satellites. If I use my SDRplay to decode telemetry, I would need to pipe the received audio through a virtual audio cable into those programs before telemetry can be decoded by either of those programs.
I have both the commercially-made HackRF One and the crowd- funded HackRF Blue devices. These are broadband transceivers that are capable of receiving at bandwidths up to 20 MHz. I have not tried using either of these when working satellites, mainly due to the lack of front-end filtering in these devices. HDSDR only supports using a HackRF device as a receiver, and I have not tried using either of these as a transmitter. The HackRF devices are capable of transmitting at low-milliwatt ranges across the spectrum they cover (officially 1 MHz to 6 GHz, but many have been able to lower the low end of that range to 100 kHz or so). The HackRF One retails at around US$ 300, depending on which reseller you buy from.
My recommendation would be to go either with a FUNcube Dongle Pro+ or SDRplay. Both are in the same price range, and work well as part of a station for working our satellites. These may cost a lot more than the cheap RTL-SDR dongles, but it is better to know the limitations of the low-end devices up front, instead of getting frustrated with them later on. The cheaper dongles can work well for receive-only applications, provided you are not near strong sources of RF (including your own transmissions), but I think the FUNcube Dongle Pro+ or SDRplay would work well alongside the original poster's FT-857.
Now if there was a software-defined transceiver capable of working our satellites full-duplex, without the need for upconverters/downconverters/transverters to cover 2m and 70cm, I'd be interested. Until then, I am OK with using an FT-817 (or similar radio) with an SDR receiver and software running on a tablet. I wrote articles about using these SDR devices with Windows tablets that ran in the AMSAT Journal and AMSAT-UK's OSCAR News in the past year. Those articles are available in PDFs from my Dropbox space:
(go to the Articles folder, then look for the files with SDR in the file names)
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK
On Fri, Jan 22, 2016 at 12:10 PM, John Toscano tosca005@umn.edu wrote:
Mentioning that you are waiting for a tax refund makes me think you are planning to dive into SDR with a fairly high-end and expensive unit, You can probably get away with spending $25 or so if you have reasonably modest expectations. Noo Elec makes a whole line of SDR devices, from inexpensive dongles to the pricier (but well worth it if you have the passion) HackRF unit. Take a look here: http://www.nooelec.com/store/sdr.html
There are some dongle vendors who sell junk. the Noo Elec units are high quality. Of course, take that recommendation from someone who owns one of their dongles, plus HackRF Blue board (clone of the HackRF and virtually unobtainable now), and a Flex-1500. ;^) 73 de W0JT/5, EL09vu