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Re: Checking modulation
#feature_request
Greetings,
? ? ? ? ? ? IMHO the major advantages offered by the tinyVNA concept are handheld portability and cost. The instrument concept is ideal for many portable field measurement needs. Professional field portable, battery powered spectrum analyzers are typically ten to a hundred times more expensive - well beyond the budget limitations of the majority of hobbyists. ? ? ? ? ? Usually the measurement of modulation components can be done conveniently?without the need for handheld portability. With modern day DSP technology using computer muscle power all that is needed for the measurement of modulation components is an inexpensive SDR receiver along with a PC running freeware such as HDSDR. A nice, quite low cost combination is SDRPlay's RSP1A receiver running under their free accessory RSP Spectrum Analyser PC software. That combination offers spectrum analysis that has a professional feel to it with frequency coverage from VLF to UHF. With the selection of a 20KHz span the RSP SA resolution bandwidth can be reduced to less than 1 Hz. ? ? ? ? ?But the relative downside of using an SDR receiver as an analyzer is that it needs to be tethered to a PC thus it does not offer a nearly as portable a concept as the tinySA. The tinySA appears to provide sufficiently narrow resolution bandwidth capability to separate most signals which IMHO should make it a good fit for many uses other than modulation component analysis. Tom, VA7TA |
Re: Request for testers for the tinySA
That will take a bit of time to configure my linux system for that.
I started with installed version to get a handle on "normal" operation. Doesn't have to work perfect that way only to get a feel. Allison ----------------------------------------- Please post here, direct emails go to a dead letter box. |
Re: Request for testers for the tinySA
Received mine today and installed a 450mah lithium battery for?
familiarization and testing. Quick question is the using set up to charge the battery from a USB source? Allison ----------------------------------------- Please post here, direct emails go to a dead letter box. |
Re: Checking modulation
#feature_request
Have a look at this post where I show the side band suppression measurement using a softrock RXTX and a tinySA
/g/HBTE/message/1126 |
Re: Checking modulation
#feature_request
I have been able to check side band suppression and carrier suppression by using a 2.5kHz tone as input. Of course this gives limited dynamic range but 40dB is possible for the opposite side band
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Re: Checking modulation
#feature_request
On Mon, May 11, 2020 at 11:09 AM, <erik@...> wrote:
Can you explain what you mean with "going close to the carrier"?========================================================== Erik, ? ?I believe he means that if your lowest resolution bandwidth is much wider than the modulation frequency then the modulation cannot be resolved in the presence of a nearby carrier.? The modulation gets integrated into the carrier.? I've "missed" many signals because they were too close to a carrier and I didn't use a narrow enough resolution bandwidth and slow enough sweep time to resolve them. ?-Herb |
Re: Checking modulation
#feature_request
Can you explain what you mean with "going close to the carrier"?
Can you give a practical example? |
Re: Checking modulation
#feature_request
Thank you all. I have checked SDRs in the past and I thought that only a few or one could go very close to carrier.
Once again, thank you. For your info, I have one SA from Aaronia Spectran something, but it wont go close enough. But it goes to 6GHz. |
Re: RFI Source Identification Signature Storage Application
Tom,
I already added the ability to have linear Y axis. Triggering is something that makes sense in zero span mode anyway. In the setting/scan speed/point time menu option you can set the time per one of the 290 scan points in microseconds. Shortest time for a full scan is 100mS Will have a look at triggering. |
Re: RFI Source Identification Signature Storage Application
Greetings Erik,
?
? ? ? ?Here are some additional comments which I hope are helpful:
?
? ? ? ?Although the screen view at " /g/tinysa/message/37 " shows a time domain capture of a signal the trace shown would need to be expanded to be useful for RFI signal signature identification. It is apparent the signal amplitude shown in this trace was compressed due to the 10dB/div Y axis scale and that the sweep duration captured too many cycles.? IMHO a linear voltage Y axis scale is necessary for this application to produce a trace similar to what would be obtained by an oscillosope connected to an AM detector output with scope settings as follows:
?
? ? ? ? ? ? ? ?- Sweep duration set to capture one or two cycles.
? ? ? ? ? ? ? ?- Vertical sensitivity set so the signal is near full amplitude of the screen.?
? ? ? ? ? ? ? ?- Single sweep triggering with storage to capture the waveform.
? ? ? ?
? ? ? With a linear scale mode and appropriate vertical gain the signal would be expanded to cover a much wider range of the Y axis. To expand the X axis signal view the availability of a sweep duration of 20 mS would be desirable for utility power related RFI. A 20mS sweep would provide a view of just a couple of cycles of 100/120 Hz related noise. Should a noise with a fundamental of 50/60 Hz be encountered the 20mS sweep duration would result in a single cycle capture which would still be useful.
?
? ? ? ?In addition to a normal sweep trigger mode the availability of a single sweep trigger option would be a significant enhancement. Because of the random inconsistencies of typical RFI noise signals a steady trigger point for repetitive sweep cycles might not be available. A single sweep mode with trace storage would be very useful for capturing a noise signature that could otherwise be blurred by the varying trigger points that very possibly would be encountered using repetitive sweep modes.??
?
Best Regards,
Tom, VA7TA |
Re: Checking modulation
#feature_request
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Re: Checking modulation
#feature_request
The tinySA uses a downconverter, selectable band pass filters and signal strength measurement all in one integrated device. As a consequence the output of the band pass filters stay's inside the device.
It is possible to demodulate AM till at most 2kHz bandwidth and with a small trick it is possible to demodulate FM. But it is impossible demodulate SSB or look inside the spectrum of a 2.7kHz wide SSB transmission as the smallest bandwidth? of the tinySA resolution filters is equal to the complete 2.7kHz SSB. As there are so? many options to use (web) SDR receivers to look at the spectrum I assumed that would not be a big problem. But none of the cheap SDR's can do a spur free fast scan of 0.1 to 350MHz to study harmonics content. |
Re: Checking modulation
#feature_request
开云体育Below is the reason that I took interest in the tinysa. I had hoped to see and demonstrate how modulation works in the HF and VHF bands. The old SA that I have now can barely do that.?Even if the tinysa was hooked to a computer to get the narrower band width that would be OK for me.? Thanks for all the effort that you are doing on the project.
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Re: Checking modulation
#feature_request
Paul Beauvilliers
Hmmm, now that I think about it a bit more, the tinysa and an SDR could make a very nice complementary pair. Paul WB1EMK? On Fri, May 8, 2020, 3:06 PM EB4APL <eb4apl@...> wrote: Or use a SDR receiver as a poor man SA. You can see modulation sidebands |
Re: Checking modulation
#feature_request
I concur: I have an RSP1A. I've used the "RSP Spectrum Analyzer" software (technically an FFT analyzer) with it on occasion ... it goes to 2GHz which is better than my ancient HP 8590A (nicknamed ole drifty).? I haven't used the optional DIY tracking generator yet.
Here is brief video on it:? |
Re: Checking modulation
#feature_request
开云体育I have one Airspy HF+ for HF and some VHF, one Softrock Ensemble for HF,? one Airspy R0 for V-UHF and a dozen or so RTL-SDR digital TV dongles repurposed for V-UHF receivers (very cheap, about $10). As the software part (in fact the receiver, the mentioned hardware are only front ends), I mostly use SDR# for all of them, but I have other software such as SDR-Console, HDSDR, etc. The bandwidths, demodulation modes and displays are all on the
software part. Regards, Ignacio, EB4APL
El 08/05/2020 a las 22:51, sala nimi
别蝉肠谤颈产颈ó:
Can you recommend one/a few which can do that? I have not found a SDR which could do that. |
Re: Checking modulation
#feature_request
开云体育Hi Luis Sure. I Got two off them ? I have not experaince with it apart form the who wrote about the combo. I will of course fire it up. I will however mainly compare to my R&S CMU200/CRTU-RU above 10MHz which has BW down to 10Hz Kind regards Kurt Fra: [email protected] <[email protected]> P? vegne af CT2FZI ? Kurt, ? How about that? I own a RSP1, compatible with? ?. ? This will be great to compare to our soon-to-be-loved-tinySA :D? ? 73 de Luís, CT2FZI ? QRV @ 145.300 MHz |?CQ0VMST (VHF REP Monsanto) ? ? On Fri, 8 May 2020 at 22:39, Kurt Poulsen <kurt@...> wrote:
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Re: Checking modulation
#feature_request
Kurt, How about that? I own a RSP1, compatible with?
?. This will be great to compare to our soon-to-be-loved-tinySA :D? 73 de Luís, CT2FZI QRV @ 145.300 MHz |?CQ0VMST (VHF REP Monsanto) On Fri, 8 May 2020 at 22:39, Kurt Poulsen <kurt@...> wrote:
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