which dongle to buy?

[Greg Troxel]

I have a SmartTee v2 and two NESDR Mini 2s, and am finding (not a
rigorous comparison) the SmartTee to work much better, so I'm inclined
to get another.

I am just trying to listen to various normal things (temp sensors, TPMS)
and finding some a bit hard to receive with the lesser dongles.

I would like to hear from people about what they'd buy out of

- NooElec NESDR Smart XTR Bundle - Premium RTL-SDR w/Extended Tuning
Range, Aluminum Enclosure, 0.5PPM TCXO, SMA Input

- Nooelec NESDR Smart v4 Bundle - Premium RTL-SDR w/Aluminum
Enclosure, 0.5PPM TCXO, SMA Input & 3 Antennas. RTL2832U &
R820T2-Based Software Defined Radio

- NESDR SMArTee v2 Bundle - Premium RTL-SDR w/Integrated Bias Tee,
Aluminum Enclosure, 0.5PPM TCXO, SMA Input, Antenna Base & 3
Antennas. RTL2832U & R820T2-Based Software Defined Radio (SDR)

It seems the v4 claims improved regulation over the v2, and the XTR two
regulators (and $10 more).

So I'm inclined to get a v4, but if you think that's confused please
tell me!

Thanks,
Greg

[DaveNF2G]

(Previous message deleted because I forgot to explain the link.)

All of my primary dongles are RTL-SDR.com v3.  I own 24 of them.  Very stable, no tuning correction required on any of them and good ears.

Here is a link to this model at Amazon:

https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2/ref=asc_df_B0129EBDS2/?tag=hyprod-20&linkCode=df0&hvadid=309707619534&hvpos=&hvnetw=g&hvrand=17731987306112428934&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1022672&hvtargid=pla-760665313632&psc=1

[Robert Terzi]

Hi Greg,

I don't have any first hand experience with the "modern" generation NooElec dongles, I've been buying RTL-SDR.com v3's and have been quite happy with them. 

I know I've read a bunch of head-to-head comparisons of the "modern" generation of dongles. I think each had some pluses and minuses that depended on your use case. I think a number of the bake offs I read were from the ADSB/rtl1090 community, where they could quantify differences in the number of successful decodes.

For long term use with rtl_433, I think they both have the key improvements that will improve reception and keep it stable 24/7:

• Heat management - metal cases and thermal pads
• frequency stability, accurate local oscillators - TXCO at 0.5PPM
• Noise reduction - better shielding, redesigned boards, better separation of USB noise from the receiver section
• SMA antenna ports
  

I can't comment on NooElec v2 vs v4, or either of those vs. the RTL-SDR.com v3, but my gut reaction is that all of those that have the above improvements all likely good enough for the majority rtl_433 applications. With rtl_433 I get quite a few more decodes with my RTL-SDR.com v3's than I do with the older generations in plastic cases with drifting local oscillators.

I hope this helps & 73,
--Rob

[Michael Cadiere]

I have 4 rtl-sdr blog v3's,  3 have a steadfast 0 ppm, the newest one is -3 ppm, 

13 Nooelec smart v4's , on average +1 ppm

Love the blog v3's for experimenting and testing..all around great dongle.

Same can be said for the Nooelec smart v4's,  because of it's dimensions,  it is my work horse, easily 

stacked in enclosures.

I have a nooelec smartee xtr,  primarily used with a patch antenna,  never had an issue with it.

For rtl_433 you can't go wrong with either a blog v3 or a smart v4,  I really wouldn't go with a bundled 

purchase,  rather just the dongle (the coaxial that comes in these bundles is not so great,the antennas are limited)

, then further purchase some sma adapters suited adding any filters, 

your feedline connections, etc..

My experience has been that two types of diy antennas work extremely well with 433, the 1/4 ground

plane & the coaxial collinear, I get far more hits from these two over my other antennas. 

[Robert Terzi]

On 9/23/2022 11:35 AM, Michael Cadiere wrote:
>
> My experience has been that two types of diy antennas work extremely well with 433, the 1/4 ground
> plane & the coaxial collinear, I get far more hits from these two over my other antennas.

Interesting -- Any pictures or links to share on the collinear?

Isn't the coaxial collinear is going to be either vertically or horizontally polarized?

How does that compare to something circularly polarized for all the 433mhz devices that are using coiled antennas?

> Same can be said for the Nooelec smart v4's,  because of it's dimensions,  it is my work horse, easily stacked in enclosures.

I've always used USB extension cables keep the receiver away from the host's noise, especially when the host is an RPI in a non-shielded case. So are you finding the shielding good enough in the current NooElec's to insert directly into the host's USB ports?

[DaveNF2G]

My SDRs are all separated from the PCs by USB cables.  I also have them grouped onto powered hubs so I can run more dongles than my computers have USB ports.  As I have serialized my dongles, there are few issues with using them via hubs.  MultiPSK always tries to grab the first available, so I have to adjust operations for that sometimes.

[Greg Troxel]

Thanks all for the recommendations. I ordered a Blog v3 and a NooElec
v4. I am trying to run rtl_433 in production on 315/433/915 so with the
previous NooElec SmarTEE v2, I should have 3 good dongles.

regarding polarization, has anyone set up two dongles with dipoles in
different orientations, covering the same frequency (perhaps LO offset?)
and compared results?

I wrote up my notes, merging the list recommendations at

https://s1.lexort.com/topics/rtl-sdr/