$20 SDR's

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N9JIG

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I am looking to get a pair of cheap SDR dongles to use with Unitrunker, DSD+ etc. around my area. I want to be able to take a laptop out to scope out various trunked systems that I cannot hear from home.

A friend has a pair of the NooElec Mini 2+ in a little USB hub that he likes. The only things wrong I see is that the do not do HF directly (needs an up-converter) and that they have a plastic case with a mini antenna connector.

Another one I have looked at is the SDR-RTL. They have an integrated SMA, metal case and pick up HF directly. The NooElec 2+ is supposed to be a better receiver but I don't really know if that is true or not.

I would like the ability to do HF without additional hardware but also want a decent VHF/UHF/800 receiver for data collection.

Any opinions on either or is there a third option in the el-cheapo dongle wars?
 

kk6jtl

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Nooelec is mostly famous in the RTL-SDR crowd for being a reputable seller of the famed RTL-SDR chips with the E4000 chip. Until the last few years their main competition was the Chinese sellers that may send you a USB stick with E4000, FC0012/13, or R820T chip.

The metal case helps in my experience. Most people will have issues with noise from the computer. The R820T2 chip is a big improvement over the R820T in general. Having the direct sampling is nice, but being able to adjust the LNA versus the AGC can be more of a personal preference.

I was an earlier adopter circa R820T being the new chip out with the E4000 chip being EOL. The LNA always going in to overload territory is annoying since I tended to have strong signals nearby causing images everywhere if I didn't manually adjust the LNA gain. This was especially true with using the Ham-It-Up.

Fast forward to last year when I got a RTL-SDR blog v3 to operate portable with my tablet. The direct sample feature seems well worth it combined with the R820T2 tuner. The TCXO is worth it on any stick you plan to take with you and not hold down to a dedicated scanning station. The R820T is not nearly as deaf as the R820T was. Just order one without the joke of antennas they like to include. Anything you'd hook your scanner or HF rigs to would be fine as long as you don't transmit next to it, especially in direct sample mode.

I'd love to compare the two but my Ham-It-Up and the chinese RTL-SDR attached at the time suffered a smoke-releasing incident when I connected a poorly labeled 14V power injector for an antenna in reverse, feeding them the 14V instead. After replacing the burnt diodes, I still haven't figured out what other SMD got fried. Been to cheap to buy another after the ICOM IC-718. Getting time to replace the Ham-It-Up and got the R820T2 instead.

The R820T and Ham-It-Up would outperform my IC-718 and RadioShack-branded Sangean ATS-505 (which are my most sensitive receivers at the moment). I'm sure the RTL-SDR/Ham-It-Up would have performed even better if I had known enough to build bandpass filters for it.

TL;DR
The metal case is what sells me on the RTL-SDR blog version of that SDR stick. $22 isn't much to break the bank over. Next round, get the Ham-It-Up with a metal case and the SMA-SMA jumper cable needed. The next thing you'll want is something with a wider bandwidth like SDRplay. Down the rabbit hole!
 

br0adband

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If you're going to use "cheap USB TV tuners" and not the higher end hardware like Airspy or SDRplay or something even higher end like HackRF/BladeRF/etc then my personal opinion on what's available out there is you'd be doing well for yourself if you got two of the latest RTL-SDR sold sticks that you just mentioned since they do have the wider frequency coverage that many people hoped for.

The aluminum housing provides much needed shielding, the SMA connector ensures you probably won't need to get a pigtail or two to make it useful with a lot of antennas (can be attached directly to the stick itself), and they're supported on most any SDR application in use today because of the RTL2838U USB controller - the tuner chip is the the R820T2 which is the 'second generation" of the Rafael Microelectronics tuner that's a bit more sensitive with somewhat less noise so yeah, those made by the RTL-SDR blog website are great devices.

They even have somewhat decent antennas compared to other similar devices, but again you'll probably want to get antennas for the specific bands you'd like to monitor, especially HF stuff (long wire type antennas, maybe even some kind of active HF loop could prove useful).

The RTL-SDR sticks are pretty much the best of the RTL-based hardware on the market today so, again, you won't regret the purchase of a few of 'em, not at all.
 

N9JIG

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Thanks!

I do have an SDRPlay, but it is sort of permanently mounted in my office under the desk near the RadarBox receiver (which is an SDR itself I presume). I am looking at ultimate portability and ease of use as well as performance.
 

slicerwizard

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Another one I have looked at is the SDR-RTL. They have an integrated SMA, metal case and pick up HF directly. The NooElec 2+ is supposed to be a better receiver but I don't really know if that is true or not.
In side by side comparisons, I've not seen any difference in VHF/UHF/700/800/900 performance.


I would like the ability to do HF without additional hardware but also want a decent VHF/UHF/800 receiver for data collection.
Haven't done any HF work with the rtl-sdr.com dongles, but I would assume that a long wire plus an impedance matching balun would be called for.


Any opinions on either or is there a third option in the el-cheapo dongle wars?
Still satisfied with the rtl-sdr.com dongle plus antenna package. The antennas are good for 50 MHz and up. The magmount has a large base for somewhat better coupling. Only downside is the 3 foot coax - it's the perfect length for working in a coffee shop, but not so much for working in the car. Delivery time is about ten days.
 

chuckinnc

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Go with the NooElec silver blog dongle requires more signal

I bought the RTL-SDR Blog V RTL2832U+ R820T2 thinking it would be a big improvement over other cheap tv donlges, I liked the idea of having a sma, easily adaptable to all my ham mobile and fixed antennas
After comparing the silver blog dongle to other R820T2 dongles, NooElec and blue plastic case generic ones I thought mine was faulty. Then I dug through in the internet and found other reviews that had the same results, it's just not as sensitive. Also the case is so fat you can't plug anything (usb) beside it on most laptops and the bias tee feture for a preamp is only 4.5v max, too lo for any preamps I have found. I really wished they would have added sma, metal case and left the insides alone.
 

N9JIG

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Well, I decided to go with the RTL-SDR Blog units. I got two of them, one turned out to be bad so Amazon replaced it the next day. So far they seem to work fine. They do get warm, but they work well both on the Mac, the SurfacePro and the PC.

I had a friend help me with the initial setup over pizza last weekend and once I got #2 replaced all was well with the world!

I decided on the RTL-SDR Blog due to the ability to do HF without a downconverter and the metal case.
 

chuckinnc

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Yep, hf is weak using the direct sampling mode but you can add a upconverter later on, they make rtl based sdr's as sensitive as alot of HF rig's, The blog is a good dongle for 24-1700mhz and works great with a upverter. I really like 2 antennas that came with it,, they are perfect for 2m and 440, I adjust them to 1/4 wave and use them with my boafeng, did require a sma barrel thou.
 
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