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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On Mon, May 11, 2020 at 11:09 AM, <erik@...> wrote:
Can you explain what you mean with "going close to the carrier"?
Can you give a practical example?
========================================================== 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
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Can you explain what you mean with "going close to the carrier"?
Can you give a practical example?
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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.
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Re: RFI Source Identification Signature Storage Application
Hi Erik,
? ? ? ? Sounds like you have the linear Y scale and sweep rate functions already nicely implemented! I imagine you will also come up with some innovative triggering modes.
Best Regards,
Tom, VA7TA
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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.
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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
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OK, very good to know. Thank you for the information.
Joe
Joe Joncas WA7MHB Lincoln County Radio Amateur Club 541-272-3207
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On May 9, 2020, at 9:44 AM, erik@... wrote:
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.
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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.
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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.
Joe
Joe Joncas WA7MHB Lincoln County Radio Amateur Club 541-272-3207
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How close to a carrier I can get? Many Hams, educators and me would like to see and check their modulators. That is, can I see what does spectrum of? SSB with 1kHz modulation look like. Or 300Hz and closer.
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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
and splatter very well in the waterfall display. You can use really
small BWs.
Regards,
Ignacio EB4APL
El 08/05/2020 a las 8:08, erik@... 别蝉肠谤颈产颈ó:
> AS the minimum RBW is 2.7kHz you can not "See" you modulation
> For that you best use a receiver and a PC with line in.
--
El software de antivirus Avast ha analizado este correo electrónico en busca de virus.
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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:?
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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.
Leif
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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 ? Kurt, How about that? I own a RSP1, compatible with? ?. This will be great to compare to our soon-to-be-loved-tinySA :D?
? QRV @ 145.300 MHz |?CQ0VMST (VHF REP Monsanto) ? ?
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On Fri, 8 May 2020 at 22:39, Kurt Poulsen < kurt@...> wrote: Hi Leif If you are ready to invest a bit then look at and purchase one of these models. Then you have a first call SDR Radio and secondly by downloading the Spectrum Analyzer software on this link ? . On this page The SDR Uno software is also to download which is the software for SDR Radio application. The are several other SDR radio software which is supporting the various SDRPlay units. For a lower budget and get started above 50MHZ then anumber of low cost USB stick can be used and then visit the ? where there is a lot of information to study Look also under the supported software And for the USB dongles Good luck Kind regards Kurt ? ? Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif ?
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Kurt,
How about that? I own a RSP1, compatible with?
?.
This will be great to compare to our soon-to-be-loved-tinySA :D?
QRV @ 145.300 MHz |?CQ0VMST (VHF REP Monsanto)
On Fri, 8 May 2020 at 22:39, Kurt Poulsen < kurt@...> wrote: Hi Leif If you are ready to invest a bit then look at and purchase one of these models. Then you have a first call SDR Radio and secondly by downloading the Spectrum Analyzer software on this link ? . On this page The SDR Uno software is also to download which is the software for SDR Radio application. The are several other SDR radio software which is supporting the various SDRPlay units. For a lower budget and get started above 50MHZ then anumber of low cost USB stick can be used and then visit the ? where there is a lot of information to study Look also under the supported software And for the USB dongles Good luck Kind regards Kurt ? ? Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif
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Hi Leif If you are ready to invest a bit then look at and purchase one of these models. Then you have a first call SDR Radio and secondly by downloading the Spectrum Analyzer software on this link ? . On this page The SDR Uno software is also to download which is the software for SDR Radio application. The are several other SDR radio software which is supporting the various SDRPlay units. For a lower budget and get started above 50MHZ then anumber of low cost USB stick can be used and then visit the ? where there is a lot of information to study Look also under the supported software And for the USB dongles Good luck Kind regards Kurt ? ? Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif
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All true. I would check FM, DSB and what ever there is.
Modulation would be easier understand with a suitable SA.
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?Use any web sdr.
Most have a waterfall option.
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Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif
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Re: Spur free dynamic range
Using a sharp tunable BPF after the LC LPF at the output of the generator I was able to measure the still present second order harmonics at -73dBc so third measurement ( at -24dB fundamental) is becoming limited by the 2rd harmonic still present but the first two measurements are only seeing internal generated second harmonic. 3rd harmonic remained invisible using the BPF so it must be much lower as was expected from the LPF.
Thanks for making me double check!
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Mat Breton
Kurt Poulsen
CT2FZI