Re: RTL SDR

Joe Puma
 

 I think the V3 dongle is a little more robust then the "Experimental: HF Direct Sampling Mode” software option for the RTL2832. When using the just the Q branch of the chip you bypass the R820T2 tuner and can tune in HF directly. The V3 dongle went a extra step from the typical chineese versions of these rtf-sdr dongle to include some filtering and other components as there is no front end after the Q branch.  

You just need a good antenna system but its sensitivity is close to my commercial radio. I think it leaves open a lot of room to build on or integrate into a project very cheaply. It is a perfect sdr receiver for pan adapter alone even if your IF is below 28.8mhz by using the Q branch. 

Joe
KD2NFC

On Apr 21, 2018, at 1:11 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:

Thanks for the info!
Sounds like the  "Experimental: HF Direct Sampling Mode" to receive frequencies 
from 500khz to 28.8mhz  is not quite ready for prime time.
Or at least, not for punters like me.
Good to know.

Jerry, KE7ER

On Sat, Apr 21, 2018 at 09:20 am, Doug W wrote:
I have the same dongle and am happy with it.  You can order it on Amazon https://www.amazon.com/RTL-SDR-Blog-RTL2832U-Software-Defined/dp/B0129EBDS2 for the same price with prime shipping to boot.  I did experiment with direct sampling but in the end broke down and bought an upconverter https://www.amazon.com/gp/product/B009LQT3G6 and later the enclosure.  It is not lost on me that all of that costs about the same as a BITX40 and by the time you throw in random connectors and what not about the same as a µBITX.  I have not tried connecting it to a Pi but using an otg adapter I have used it with an old android phone.  I haven't used it on the phone in a while but I seem to remember using the free version of SDR Touch.  Prior to having a real antenna I was using this balun https://www.amazon.com/gp/product/B00R09WHT6 and random wire with limited success and a few cheap telescoping whip antennas.
I just did a quick search and as usual Adafruit has a solid tutorial on with links to libraries https://learn.adafruit.com/freq-show-raspberry-pi-rtl-sdr-scanner?view=all
For general ideas and knowledge you can't beat https://www.rtl-sdr.com/

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