Here is an edited highlight of what was posted by 'Mr Genoa' a few weeks ago.....
According to "SDRplay limited" the SDRplay is a "development platform" and "it is designed by engineers for engineers".At the moment me (and a lot of other enthusiasts) are not capable of developing software for SDRplay even if we would like to in the future...at the moment we like to use it as a good price/performance SDR receiver.
So I'm opening this new discussion thread to collect and share "end-user" experiences, info, tips, techniques. On one hand SWL and radio enthusiast can share their experiences, on the other hand I hope "SDRplay limited" people can take info to improve the product, the documentation, release new "end-user" technical guidance etc etc etc.\
Any contribution is welcome, even if I suggest to get a proper "quantitative" / "semi-quantitative" approach to our discussion if possible... ......
Listening report Today (early Jan date) at 10.30 UTC I tuned my SDRplay around 20MHz using 1.5 bw and 1.5 sr.
Antenna: random wire 12m on the roof (20 m over sea level). a near "desert land" it come up something. After some work with the zoom i identified vfo reading 20.047.500 -> _ . . --> single letter beacon "D" vfo reading 20.047.800 -> _ . _ . --> single letter beacon "C" those two in the waterfall were "printed black on white", very clear identification.
Some times i heard an other vanishing signal, not clear in the waterfall, very confusing. After some google search it was identified as "S" at vfo reading 20.047.700. Very low over the noise but surely it was there in the audio output.
Doing a "cross check" with Global Tuners (qrg.globaltuners.com) I find out
20.0477 D sevastopol ukraine
20.0479 S severomorsk russia
20.048 C moscow russia
According to Global Tuners my vfo was off tune 200Hz more or less.
Unfortunately there in no adjustment parameter for SDRplay with SDR#.
Doing an other cross check with SDR-WEB "TWENTE".
From that location only C was visible/audible at vfo= 20.048.1
Doing an other cross check with my FCDPP (same antenna)
Only D was visible/audible at vfo=20.047.700 (here i have a f. correction of 3.9 ppm that was tested in one year of operations mainly on MS/SW)
Summary: SDRlay has good sensitivity and selectivity in this "use-case"
Nice to have: a frequency correction parameter (please consider this in the next sdr# plugin release). Bye.
It's not in the plugin but in SDR# itself.
There is a check box with the word Shift beside. Once enable you can enter a correction value in the numeric box on the right of it.
Example: I tuned an FM station at 107.7 Mhz if I enter 100000 in the Shift value the displayed frequency at the top of the screen will be 107.8 Mhz
I know it a big correction but it's only to illustrate the effect. You can enter any wanted value.
Hope it was what you're looking for.
When I opened this topic, my aim was to exchange experience with other sdrplay users.
Of course everybody is free to talk about any subject related to SWLing...
It is a sort of "call-to-army"
I suppose the main usage of "Shift" is when you use a downconverter with RTL-SDR or so
anyway good hint also for frequency correction.
In my experience with rtl-sdr "standard" there is no use to look at digit below 1khz (as a very general and quick rule)
since there is a thermal drift. It is an easy test that each one can do by himself, at the moment I had no time
to measure this with sdrplay.
I don't know if there are stability figures about sdrplay. If someone has such figures, please post it.
Genoa (I like this new nickname!)
[Basically there are around the world scientific stations that study the ionosphere transmitting a "slope" in HF
starting let say at 2000khz with a slope let say 100khz/s (as result you see a trasversal line on your waterfall display)]
I wonder if sdrplay with his 8MHz "scope" could be used to classify those ionosonde. I mean, given the signal on your
screen you understand who is sending the signal.
Anyone has experience in dxing ionosonde? Please post!
Without personal experience, googling here and there, I understand that i can do this:
-- keep a couple of point on the waterfall P1(f,t) P2(f,t) (of course this process is prone to error)
-- then I can guess the time T0 when the slope started at (let say) 2000khz, with an error depending of P1 and P2 accuracy
If I had an up-to-date time-schedule list of tx stations I could guess the station (provided each station transmit at different schedules with
happy to see you back. I think that we are up to now, beside Jon ,the two most active user on the forum.
Proud that the frequency correction hint helped you.
On your side you gave me an answer about a thing I was wandering about ---> the sweeping line across the Spectrum observed time to time.
I was suspecting something a bit that way. So I read on the net about Ionosonde you told.
It's used, among other things, to determine the best frequency for transmitting via the Ionosphere bouncing.
On my side I'm exploring the "Under the Hood" aspect of SDR. I allways like to understand the things I use.
I'm actually building an Excel spreadsheet to decipher the theory behind all those math formulas applied to SDR with some animated graphs.
I'm far from being a communication engineer so I must dig all over the net to find information's to understand all that.
Up to now I'm pretty well advanced in my spreadsheet development. I want to include the simulation for many kind of modulation
( AM, FM, SSB, DSB, PSK, QAM )
It would be a nice tool to help newbies ( like I was few weeks ago ) to understand what happen in SDR. This could be post on the download of the site if SDRPlay team agree.
After that It will be the demodulation side be explored.
I also installed GNURadio on a virtual Ubuntu machine. More on that later.
Few.....not enough of 24h a day to do all that. At 57 years it keep all the neurons boiling!!!!!
Have fun gang......
Re the frequency discrepancy I don't think the 'shift' feature is suitable, as it adds or subtracts a fixed offset at all frequencies, whereas the SDRPlay (in common with all PLL synthesised tuners) has a 'per Hertz' offset. This means an error of 100 Hz at 10MHz will be an error of 1000 Hz at 100 MHz and an error of 10KHz at 1000MHz. The only way to correct this is to pull the reference xtal onto frequency either by hardware (a trimmer!) or via a software feature.
It would be nice to see this feature, but for now my SDRPlay's error has been corrected with a 20pf trimmer.