SDRplay and SWL usage

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sdrplay
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SDRplay and SWL usage

Postby sdrplay » Wed Jan 07, 2015 11:37 am

-- Overview of this new discussion --\nAccording to "SDRplay limited" the SDRplay is a "development platform" and "it is designed by engineers for engineers".\nAt the moment me (and I lot of other enthusiast) I''m not able to develop software for SDRplay even if i will like to in the future...\nAt the moment I like to use it as a good price/performance SDR receiver.\n\nI hope the title is properly focused on my target.\nI''m opening this new discussion thread to collect and share "end-user" experiences, info, tips, techniques. \n--> on one hand SWL and radio enthusiast can share their experiences\n--> 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.\n\nAny contribution is wellcome, even if I suggest to get a proper "quantitative" / "semi-quantitative" approach to our discussion if possible... :-)\n\nOnce for ever, I apologize for my english. By the way, I''m based in Genoa (seaside town in north of Italy.)

sdrplay
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Joined: Wed Jan 07, 2015 7:58 am

Re: SDRplay and SWL usage

Postby sdrplay » Wed Jan 07, 2015 11:57 am

Listening report\n\nToday at 10.30 UTC I tuned my SDRplay around 20MHz using 1.5 bw and 1.5 sr.\nSoftware: SDR#. Antenna: random wire 12m on the roof (20 m over sea level).\nIn a near "desert land" it come up something. After some work with the zoom i identified\nvfo reading 20.047.500 -> _ . . --> single letter beacon "D"\nvfo reading 20.047.800 -> _ . _ . --> single letter beacon "C"\nthose two in the waterfall were "printed black on white", very clear identification.\nSome times i heard an other vanishing signal, not clear in the waterfall, very confuse. 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.\n\nDoing a "cross check" with Global Tuners (qrg.globaltuners.com) I find out\n20.0477 D sevastopol ukraine\n20.0479 S severomorsk russia\n20.048 C moscow russia\n\nAccording to Global Tuners my vfo was off tune 200Hz more or less.\nUnfortunately there in no adjustment parameter for SDRplay with SDR#.\n\nDoing an other cross check with SDR-WEB "TWENTE". \nFrom that location only C was visible/audible at vfo= 20.048.1\n\nDoing an other cross check with my FCDPP (same antenna)\nOnly 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)\n\nSummary:\n-- sdrplay has a good sensitivity and selectivity in the "use-case"\n-- nice to have: a frequency correction parameter (please consider this in the next sdr# plugin release).\n\nBye.\n

jon
Posts: 293
Joined: Tue Jan 06, 2015 10:48 am

Re: SDRplay and SWL usage

Postby jon » Sun Jan 25, 2015 11:41 am

I would like to follow up on this interesting post from Genoa (Dear Mr Genoa - please re-register on our new forum so that we can make this an active thread again!)

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.
Software: SDR#.
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.

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Quimquim
Posts: 28
Joined: Wed Jan 07, 2015 10:40 pm
Location: Quebec Canada

Re: SDRplay and SWL usage

Postby Quimquim » Sun Jan 25, 2015 4:59 pm

Hi, I don't know if you talk about a correction between the tuned frequency and the displayed one, but there is a frequency correction option in SDR#.

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.

Have fun :mrgreen:

Quimquim
Stay tuned !!!! :mrgreen:

Quimquim :P

CaptainNemo
Posts: 114
Joined: Mon Jan 05, 2015 1:22 pm
Location: Genoa - Italy

Re: SDRplay and SWL usage

Postby CaptainNemo » Tue Jan 27, 2015 9:30 am

Hi there... back again! First the forum was changed, then my pc was stolen...
--------
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" :lol:
--------

CaptainNemo
Posts: 114
Joined: Mon Jan 05, 2015 1:22 pm
Location: Genoa - Italy

Re: SDRplay and SWL usage

Postby CaptainNemo » Tue Jan 27, 2015 9:44 am

Tnx Quimquim for your hint about freq correction.
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!)

CaptainNemo
Posts: 114
Joined: Mon Jan 05, 2015 1:22 pm
Location: Genoa - Italy

Re: SDRplay and SWL usage

Postby CaptainNemo » Tue Jan 27, 2015 10:09 am

Just as subject for "SDRplayer", I'm calling for info about "ionosonde" sometimes called digisonde or chirp
[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
enough time-spacing).

Bye
Genoa.

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Quimquim
Posts: 28
Joined: Wed Jan 07, 2015 10:40 pm
Location: Quebec Canada

Re: SDRplay and SWL usage

Postby Quimquim » Tue Jan 27, 2015 11:31 pm

Hi Nemo,
happy to see you back. I think that we are up to now, beside Jon 8-),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!!!!! :idea:

Have fun gang...... :D

Quimquim
Stay tuned !!!! :mrgreen:

Quimquim :P

CaptainNemo
Posts: 114
Joined: Mon Jan 05, 2015 1:22 pm
Location: Genoa - Italy

Re: SDRplay and SWL usage

Postby CaptainNemo » Wed Jan 28, 2015 2:39 pm

I'll be 57 next summer... :lol: with the last reform of pension system I will retire at 67 ... :shock:

g1hbe
Posts: 217
Joined: Sat Jan 17, 2015 3:28 pm
Location: Cheshire

Re: SDRplay and SWL usage

Postby g1hbe » Fri Jan 30, 2015 10:25 pm

Hello all. After some delay(!) I have managed to return to the forum.
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. :mrgreen:
Andy


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