SDR Newbie Question

Discussion in 'Software Defined Radio (SDR)' started by KN4SLJ, Oct 25, 2020.

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  1. W6UV

    W6UV Premium Subscriber QRZ Page

    RTL dongles are cheap toys. Get yourself an SDRplay RSP1A. It's only about 100 bucks, and a lot better than a $15 dongle.
    K2XT likes this.
  2. KA9JLM

    KA9JLM Ham Member QRZ Page

    Many little toys are a lot more fun than 1 big one. :)
    AJ4GQ and N2HUN like this.
  3. W6UV

    W6UV Premium Subscriber QRZ Page

    I disagree. I'd rather have one quality item than a bunch of pieces of junk.
  4. KN4SLJ

    KN4SLJ Ham Member QRZ Page

    My intention was to get a cheap but well-reviewed device to see if I'd like it enough to go whole-hog and get an expensive SDR. I was previously considering getting a entry-level HF TX/RX rig but I just honestly don't think I'd TX enough for it to be worth the huge cost. I like the idea of being to monitor pretty much...anything... though, so I decided to give SDR a good look. Despite the RTL-SDR's limitations, I'm amazed that so much functionality can be crammed into a dongle that's roughly the same size as a pack of chewing gum. I've been listening in on all kinds of stuff. Commercial radio, SW broadcast, and my city's traffic light telemetry system. The waterfall lights up like crazy at about 430 mhz with devices clearly talking to each other. Fascinating stuff. I occasionally get a weird digital-sounding interference on 70cm when I'm downtown, so a mystery has been solved. I've built the MW band-reject filter and it works. It's one of the simpler designs out there. 4 inductors and three 1000pF caps. I still get a bit of MW bleedthrough but it's MUCH reduced. I haven't got it in an RF enclosure yet though so that may be (part of) the issue. I'll probably wind up getting something nicer eventually. I'm really interested in decoding some of these digital/PCM streams I keep coming across. I've heard that many of them aren't encrypted.
    KA4FIX, WA4SIX and N2HUN like this.
  5. N2HUN

    N2HUN Ham Member QRZ Page

    I heartily agree OM. The RTL-SDR dongles can't be beat as far as the prices go.
  6. KA9JLM

    KA9JLM Ham Member QRZ Page

    I have bought many different models, Just to play with.

    My first cost around $ 150, It included the Up/Down converter for best operation on HF.

    The Version 3 @ $20 works very well. Just add the filters that you need. For HF a antenna tuner can reject a lot of out of band overloading.

    Now a days, The battery for a nice toy is over $20. So $20 for a SDR Ver 3, No battery required, Is a winner. :)

    N2HUN likes this.
  7. N6YWU

    N6YWU Ham Member QRZ Page

    I have an RSP1a, RSP2, Airspy HF+ Discovery, Hermes Lite 2, and Red Pitaya-16 SDRs. They cost from 5X to 25X more than my RTL-SDR V.3. I was surprised to find out that I could decode a fair amount of 20M FT8 signals from the RTL-SDR in 8-bit Direct Sampling mode, and that the more expensive SDRs did not allow decoding 5 to 25 times more signal. So in price/performance, the RTL-SDR performed quite well. A very inexpensive way to get ones feet wet and decide if they want to invest more in SDR stuff.
    N2HUN and KA9JLM like this.
  8. KA9JLM

    KA9JLM Ham Member QRZ Page

    It is very interesting how a $ 20.00 toy can suck you in to spending $ 2,000.00 for a new radio.
    N2HUN and N6YWU like this.
  9. WA4SIX

    WA4SIX Ham Member QRZ Page

    Started with the first generation, went to the V3, then to the LimeSDR-USB (2 of them).... Yeah, the dongles are great to start out. I still use mine regularly.
    One of my Limes has a 3W driver amp, then a PA/filter board from an FT-857D, controlled by an arduino. It's my homebrew Shack in a box for about $450. TX & RX audio on SSB are superb. Works very well on AM, too.
    Using SDR-Console for software.

    The dongles are like buying your first car....

    N2HUN and KA9JLM like this.
  10. K2XT

    K2XT Premium Subscriber QRZ Page

    On my RSP1 using HDSDR software if I adjust the rf gain up the noise floor rises smoothly then suddenly jumps up 30 db, as if some stage is oscillating. In that mode there is all sorts of crap and spurious signals.
    N2HUN likes this.

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