inexpensive RTL SDR's on Ebay

[Bill F]

Has anyone had any luck with these?
http://www.ebay.com/itm/100KHz-1-7GHz-Full-band-UV-HF-RTL-SDR-USB-Tuner-Receiver-R820T-8232-Ham-Radio-/201258847047?hash=item2edbf64b47:g:DxsAAOSwzgRW0~HS#rwid

[Josh]

I've not used one of those model, however the cost of the rtl v3 dongle is so low and it does so much I have to assume those who buy a cheaper dongle just don't know about the v3. The tcxo alone is worth any cost increase over the cheapest of the cheap dongles.

[RST111]

I agree with Josh.  I got the RTL-SDR v3 dongle on a whim, and it was a great introduction to SDR for me.  Besides the clock, if you use the v3 with SDR# and set it to use only the Q stream, it can receive HF without a downconverter.  It should work with other SDR software that allows Q-stream only, but I haven't tried.

The metal case is nice and heat dispersion improvements are nice, too, because I have felt it get warm.

I got mine on Amazon.  $25 with free 2 day shipping if you have prime.  https://www.amazon.com/dp/B011HVUEME/

The antennas are worthless for HF, though.  I hooked it up to my longwire.  For that reason, I got this pigtail kit of theirs which I also recommend as well-built.  I've used it for a few things besides the dongle.  https://www.amazon.com/RTL-SDR-Blog-Pigtail-Adapters-Bundle/dp/B0132N1DM0/

I don't work for the blog or get any kind of payback.  Just a satisfied customer. :-)


Edited to add:  Looking closer at the eBay description I see "How to receive HF  Used the program of SDR # with RTL configured to direct sampling of the signal Q, as shown in the following figure"

So, yeah, it does the same as the RTL-SDR dongle except the ebay device has 2 antenna inputs.  I can't speak for the eBay device, but it works fine with the RTL-SDR dongle with the following caveats:  If you're just playing, it will be good as-is.  You will hear shortwave, etc.   However, it easily overloads, gets images etc., as one would expect with a $25 radio.  So if you want to do something more than basic, like hunt signals, you will need to add filters (esp AM for HF and FM broadcast for VHF/UHF bands).  A pre-selector helps as well.

Having said that, if you're paying say $40 for two filters and maybe $75 for a pre-selector, the total cost is now ~$140.  For that you could get an SDRPlay if you're only interested in HF.

[ChrisSmolinski]

Having said that, if you're paying say $40 for two filters and maybe $75 for a pre-selector, the total cost is now ~$140.  For that you could get an SDRPlay if you're only interested in HF.

Exactly.

The RTL dongles are great for VHF/UHF for the price (I have two). Significantly less great for HF, and once you add all these additions to make them [barely] usable on HF, you could have just bought yourself an SDR that actually works fairly well on HF.  I suppose a bare bones setup works OK as a spectrum monitor, but I'd really caution against throwing too much good money after bad here.

[Josh]

Agreed, once you start figuring in filters to keep the spectrum narrow for the RTL rx's, might as well spend the money on a SDRPlay or Airspy, these make a world of difference. That being said, the RTL, especially the V3, is indeed worthy on V/UHF and have useful hi/lowpass rf filtering built into the tuner chip that can be adjusted by the controlling app. This rf filtering would help in many ways on HF but can't be used in direct sampling mode where the tuner is bypassed, making the V3 and others with that tuner chip most at home on V/UHF.