4 ms·

Linked is a specific model on Amazon but you can just use any rtlsdr stick. They start at about 10$. http://sdr.osmocom.org/trac/wiki/rtl-sdr http://sdr.osmocom

by anc84 11y ago

Linked is a specific model on Amazon but you can just use any rtlsdr stick. They start at about 10$. http://sdr.osmocom.org/trac/wiki/rtl-sdr http://sdr.osmocom.org/trac/wiki/rtl-sdr Great fun and great gift for hacker types.

maaarghk 11y ago
This is pretty cool. Quite tempted to buy one and start messing around!
- anc84 11y ago
  If you have the time but not the money, let me buy you one! It might take a while to ship from China and your local customs might not like it though.
  - maaarghk 11y ago
    Thank you for the offer but it's the opposite way round! I'd only be distracting myself from my fifteen other hobbies. :{ But I caved and got the $7 one from aliexpress listed above.. :) It might take longer to arrive, but that's not really a bad thing as I won't have time to play with it at the minute anyway.
    - anc84 11y ago
      Thought so! Same here...
ultramancool 11y ago
Yeah, try aliexpress or ebay if you want to get a good price on one. They're often identical devices, some of the ones you find on Amazon are just companies who got their logo stamped on the same ones you can order off aliexpress for less than half the cost. In fact I own one which looks identical to the one pictured in the article but I think I got it for a lot cheaper... http://www.aliexpress.com/item/USB-2-0-Digital-DVB-T-SDR-DAB-FM-HDTV-TV-Tuner-Receiver-Stick-RTL2832U-R820T2/32313795742.html?ws_ab_test=searchweb201556_3_79_78_77_80,searchweb201644_5,searchweb201560_1 http://www.aliexpress.com/item/USB-2-0-Digital-DVB-T-SDR-DAB... $7.35 instead of $21.95... I think the antenna is a little nicer on the NooElec one, but it's 3x the cost and neither is particularly good (as the author of this article points out), you can probably find a much better one if you look around.
- makomk 11y ago
  The cheap ones off Aliexpress have fairly inaccurate crystals - they're 100 ppm or more off, which you can compensate for to a certain extent but that's another step. By comparison, the rtl-sdr.com one looks particularly spiffy: http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
  - ultramancool 11y ago
    In my experience they're 30-70 ppm off, never seen one over 100, but it's extremely easy to adjust and all apps pretty much support it, most tutorials tell you right off the bat how to do it. Once you've got them configured they're surprisingly pretty solid. The rtl-sdr.com dongles there say 1-2 PPM, but that's only 1-2 PPM temperature drift, right? The one I linked also uses the R820T2 tuner, which does seem to be somewhat more accurate. You're still going to have to mess around to get the right offset at first. Just less messing around for the first 5-10 minutes while it heats up. Honestly, if it's something you're really interested in and want to put some money into I'd buy a HackRF instead, $300-400 but you'll be able to dump way more spectrum and transmit.
    - Veratyr 11y ago
      How solid they are depends on the environment they're in. They primarily vary by temperature so if you're using them in an air conditioned room they're unlikely to have issues but if you leave them outside you'll notice the PPM value varying throughout the day.
    - makomk 11y ago
      I unfortunately don't have one of the rtl-sdr.com dongles (wish I did) but the spec says there's a 2 PPM initial error plus 1 PPM temperature drift, which is fairly reasonable for a cheap TCXO. My current dongle is a cheap one from AliExpress with slightly over 100 PPM of offset, and finding a calibration procedure that actually worked was... interesting.

by anc84 11y ago

maaarghk 11y ago

This is pretty cool. Quite tempted to buy one and start messing around!

anc84 11y ago
If you have the time but not the money, let me buy you one! It might take a while to ship from China and your local customs might not like it though.
- maaarghk 11y ago
  Thank you for the offer but it's the opposite way round! I'd only be distracting myself from my fifteen other hobbies. :{ But I caved and got the $7 one from aliexpress listed above.. :) It might take longer to arrive, but that's not really a bad thing as I won't have time to play with it at the minute anyway.
  - anc84 11y ago
    Thought so! Same here...

ultramancool 11y ago

Yeah, try aliexpress or ebay if you want to get a good price on one. They're often identical devices, some of the ones you find on Amazon are just companies who got their logo stamped on the same ones you can order off aliexpress for less than half the cost. In fact I own one which looks identical to the one pictured in the article but I think I got it for a lot cheaper... http://www.aliexpress.com/item/USB-2-0-Digital-DVB-T-SDR-DAB-FM-HDTV-TV-Tuner-Receiver-Stick-RTL2832U-R820T2/32313795742.html?ws_ab_test=searchweb201556_3_79_78_77_80,searchweb201644_5,searchweb201560_1 http://www.aliexpress.com/item/USB-2-0-Digital-DVB-T-SDR-DAB... $7.35 instead of $21.95... I think the antenna is a little nicer on the NooElec one, but it's 3x the cost and neither is particularly good (as the author of this article points out), you can probably find a much better one if you look around.

makomk 11y ago
The cheap ones off Aliexpress have fairly inaccurate crystals - they're 100 ppm or more off, which you can compensate for to a certain extent but that's another step. By comparison, the rtl-sdr.com one looks particularly spiffy: http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/ http://www.rtl-sdr.com/buy-rtl-sdr-dvb-t-dongles/
- ultramancool 11y ago
  In my experience they're 30-70 ppm off, never seen one over 100, but it's extremely easy to adjust and all apps pretty much support it, most tutorials tell you right off the bat how to do it. Once you've got them configured they're surprisingly pretty solid. The rtl-sdr.com dongles there say 1-2 PPM, but that's only 1-2 PPM temperature drift, right? The one I linked also uses the R820T2 tuner, which does seem to be somewhat more accurate. You're still going to have to mess around to get the right offset at first. Just less messing around for the first 5-10 minutes while it heats up. Honestly, if it's something you're really interested in and want to put some money into I'd buy a HackRF instead, $300-400 but you'll be able to dump way more spectrum and transmit.
  - Veratyr 11y ago
    How solid they are depends on the environment they're in. They primarily vary by temperature so if you're using them in an air conditioned room they're unlikely to have issues but if you leave them outside you'll notice the PPM value varying throughout the day.
  - makomk 11y ago
    I unfortunately don't have one of the rtl-sdr.com dongles (wish I did) but the spec says there's a 2 PPM initial error plus 1 PPM temperature drift, which is fairly reasonable for a cheap TCXO. My current dongle is a cheap one from AliExpress with slightly over 100 PPM of offset, and finding a calibration procedure that actually worked was... interesting.