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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
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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OK, very good to know. Thank you for the information.

Joe

Joe Joncas WA7MHB
Lincoln County Radio Amateur Club
541-272-3207





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.

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

 

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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





On May 7, 2020, at 4:28 PM, sala nimi <sala.nimi@...> wrote:

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.

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
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.
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

 

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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 

    

  

 

	

      
		Libre de virus.  		
	



 



				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				





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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
Fra: [email protected] <[email protected]> P? vegne af CT2FZI
Sendt: 9. maj 2020 00:01
Til: [email protected]
Emne: Re: [tinysa] 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:
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 ?
Fra: [email protected] <[email protected]> P? vegne af sala nimi
Sendt: 8. maj 2020 22:52
Til: [email protected]
Emne: Re: [tinysa] Checking modulation #feature_request
?
Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif 
?

					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							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:
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 ?
Fra: [email protected] <[email protected]> P? vegne af sala nimi
Sendt: 8. maj 2020 22:52
Til: [email protected]
Emne: Re: [tinysa] Checking modulation #feature_request
?
Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif 





					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				





开云体育
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 ?
Fra: [email protected] <[email protected]> P? vegne af sala nimi
Sendt: 8. maj 2020 22:52
Til: [email protected]
Emne: Re: [tinysa] Checking modulation #feature_request
?
Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif 

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
All true. I would check FM, DSB and what ever there is.
Modulation would be easier understand with a suitable SA.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
?Use any web sdr.
Most have a waterfall option.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Can you recommend one/a few which can do that? I have not found a SDR which could do that.
Leif

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							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!

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
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.

				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Checking modulation
							

								
									
										
											#feature_request
										
									
								
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
To measure close in products you need a much narrower RBW typical is 
30-100hz, maybe 300hz.? You also need to insure the carrier if any is 
not overloading the input of the SA.

If true SSB source and no distortion there is only one signal that being the
sum or difference of the carrier and some carrier leakage which for any 
competent system should be at least -40dbc or better.

Its easy to do but you need a suitably narrow bandwidth system.

Allison
-----------------------------------------
Please post here, direct emails go to a dead letter box.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Spur free dynamic range
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Your expectation on harmonics are dependent on the cause.

For example input overload can do that, often you get other products like 3/2s
as you have two signals generally the source and then the internal 
signal with some offset.? Yes, third harmonic divided by 2, higher order is 
possible as well.

it is also critical to know the generators harmonic level, hence the reason 
for the setup I use with filters.? Most of the HP generators are very clean but
that is not absolute, there is always some.

Allison
-----------------------------------------
Please post here, direct emails go to a dead letter box.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: Spur free dynamic range
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
It slowly occurred to me that I am doing this still too complicated and there is an even simpler measurement approach. (if this is too much details for this group feel free to shut me up)

Using only one clean signal (harmonics really low) followed by a step attenuator it should be possible to observe the harmonics generated inside the tinySA and be able to predict everything what happens and calculate the IIP3 and SFDR
So I took a regular tinySA (no "special" this time) and started with a powerlevel calibrated signal at about -4dBm at about 9MHz.

This is how it looks with 0dB external attenuation



2nd harmonic at -54dBc and 3rd harmonic at -63dBc.
Calculating the IIP3 gives (-4 + (-4 - -63)/2) = +25dBm

Reducing the input with 10dB (using the external step attenuator) implies the 2nd harmonic should move to -64dBc and the 3rd to -83dBc and the IIP3 should stay the same



2nd order moves to -66dBc (seems ok) and 3rd order moves down 30dB so into the noise floor.?Let's pessimistically assume it is at -98dB so -84dBc. All looks good.
Calculating the IIP3 gives (-14 + ( -14 - -84)/2 ) = +21dBm which is a bit less so my assumption about the level of the 3rd harmonic may be too pessimistic.

Further reducing the input to -24dBm gives:



The RBW was reduced to 10kHz otherwise the 2nd harmonic would be invisible. Its now at -100dBm thus -76dBc which is indeed again 10dB better as it should be.
With the RBW at 30kHz this would have been invisible so the SFDR with an RBW of 30kHz seems to be 76dB.
In other words:?The internally generated intermodulation products of on or more tones at -24dBm or lower will no longer be visible at an RBW of 30kHz

So much to learn.

				
				
				
			

			
				

				

					
						
	
		
			
				
			
		
		

			
				
			
			
			

				
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