Thanks for the in-depth analysis! I use an RSP spectrum analyzer (RSPdx hardware) daily and it works fantastic. Many improvements were made in v1.1 of the software vs the 1.0 version which you have here. Just a couple of corrections - for some of the tests, you are using a 2khz span which means 200hz per division. So the sidebands from your signal generator are roughly at +/- 200hz from center, not 2khz. So at 21:40, the Rigol DSA-815 isn't showing them because of the 100hz RBW limitation of that machine. They are still there. SO grateful to Steve Andrew for the software (he seems to have abandoned the project) and to you for these in-depth tests and explanations!
Great analysis and findings on the limitations and capabilities on various types of Spectrum Analyzers. They've now become very compact affordable and prove themselves to be an indispensable tool for any amateur radio hobbyist or RF engineer. Keep up the great work.
Thank you ! this was a very good video . The first time I used the RSP analyzer , I shut it off in 5 minutes and called it junk because it did not have modulation type and audio. I was comparing it to another SDR play program . ( SDR uno ) I have a lot of RF interference on my back deck in the 2 meter band. The noise floor with UNO was always locked onto -95 dbm. I took off the antenna from the RSP Play and it never changed . I put the SDR play into a dummy load and it was the same -95dm. I dumped that program and went to the RSP spectrum analyzer . I found a huge difference in the readings. If I put the SDR into a dummy load the noise floor dropped 25-30 dbm. I could move my antenna around and I could watch the noise floor move with the antenna. I could not with the SDR UNO. With this analyser I could find a place on my deck to place my antenna with the lowest noise floor.. Good luck doing that with UNO . I still have a high noise floor in the 2 meter band but at least I sniffed out a spot with a low noise floor so I can hear the local repeaters.
Excellent video. I've watched a lot of videos on Spectrum Analyzers and I finally think I understand RBW. Thanks very much for explaining RBW in a way that it finally made sense to me. Robert, K6FNI
Hi, I noticed when you were not experiencing the sidebands on your signal the noise floor was around the level of the sidebands e.g. around -80 to -90DB.
Thanks for this. I have thought about putting my RSP into a shielded box, it seems it is not necessary though, given the excellent noise floor. Have you solved the mystery of the 1 MHz sidebands yet? Cheers,
Thanks for your comment and question. I am convinced that the sidebands are being produced outside the RSP1A, i.e. they are due to a strong external signal interacting with a non-linearity outside the SDR that produces a modulated signal at these very low levels. These exist, of course, in almost all places outside of shielded labs, etc. but are often not noticed unless you are looking near the noise floor as we are in this case. One reason I am sure it is outside the RSP1A is that the Signal Hound SA44 displays almost exactly the same signals. They are not as obvious on standalone spectrum analyzers (like the Siglent, Rigol, or Instek) so it may be due to the computer connection (both the SDR and SA44 use USB to power and operate the hardware).
In my opinion, the RSP Spectrum Analyzer is vastly superior to the FFT of either of those scopes. The RSP is not only technically superior, but also much easier to use.
@@tomtektest8042 Thank you for your opinion. Can't afford a Spectrum Analyzer yet. Will look into RSP option. First time I hear about RSP product and of course the software. Thanks again and look forward to more videos.
Hi.. and Thanks! I have the Triarchy VSG6 and their Spectrum Analyzer. (The earlier 6GHz model) The software is terrible IMHO. I had it functional and was able to apply the calibration files in the original ToughBook (win 7 pro) laptop I had back when I originally purchased the Triarchy Tech devices. But... It will not load the cal files on my new ThinkPad “portable workstation” (aka “laptop” 🙄) Their support is just plain awful. I DO like the Spike application for the SignalHound line. The company is entirely US based and the hardware is produced here as well. The tech support is incredibly good for an instrumentation company. I am contemplating purchasing a spec analyzer and separate tracking generator for a project I have in mind. The Signal Path and Comms Prepper TH-cam channels both have very good review videos and they are both very reputable sources IMHO. I also have an Agilent N9340b “handheld” spec analyzer. It is excellent and durable... BUT .. the display is very difficult to read in anything other than dim light environments. It goes to 3GHz, but most of my work is in public safety 2-way comms, so I rarely go above 900mhz. The cost was far more than I felt comfortable spending at the time ($6695 with TG and pre-amp options). but I somehow justified it to myself. 🙄 I primarily Use it as a hobbyist and, now that I’m retired.. and I occasionally tune a duplexer or cavity for friends and the occasional prior client. Definitely not worth it for what I am doing... But... believe it or not... with the higher-tier tools available to me, it always seems like I just reach for my “economy” DSA815tg. It is lightweight (1/2 the weight of the Agilent), does not require a functional computer, has a great (BRIGHT!) display and it is quite easy to use. (especially for knuckleheads like me 😉😷🤣) AND... it was CHEAP (compared to the other solutions I own) at $1875 with TG option and Rigol soft case. Might I suggest the BEST ACCESSORY for RF ?. It is by far the BEST investment I’ve made in the past decade. The RF Industries “Unidapt” connector set. It is a “universal” conmector set that includes nearly every RF connector (depending on the set you purchase.. they have 3 or 4 sets ranging from $60 - $550) I won’t be able to do it justice here, so go and Google it. PLEASE 🐔 Two things I should mention: absolutely purchase the “WHITE BRONZE” finish. (a few dollars more than the nickel plated, but the finish will last longer and no issues with PIM / intermod). and... take a look at their BLUE interconnect cables. While you can use your own, you will get much more use out of the set when you do not have to sacrifice extra connectors to interface with your own cables. The “BLUE” Unidapt coax cables are made by Belden specifically for Unidaot. It is a hybrid between the RG400 and RG58 cable types. Silver plated stranded center conductor / silver-plated DOUBLE SHIELDING/ ultra flexible/ very nice strain relief boots installed / silver plated “Unidapt” specialty fittings installed on both ends. (they mate directly with the connectors/ adapters that come with the sets) The cables are 5’ and 6’ in length and cost around $22-35@. Compare that to my Pasternack and other “high tier” cables and these are much nicer and a fraction of the cost. Forgot... just a quick list of connector types in my “medium” Unidapt set (2x of each type) N Male / N female / BNC male / BNC female / F male / F female / SMA male / SMA female MCX male / MCX female / RCA “phono” male / RCA “phono” female / 7/16” DIN male and female AND.... 6x “couplers” (threaded double female Unidapt on each side) Thanks for your channel and videos! I will be binge watching all weekend. 👍🏻 73 from NJ The Salty Cracker Army is Legion 🧂🧂🧂🧂🇺🇸🇺🇸🇺🇸🧂🧂🧂🧂 Epstein did NOT kill himself. And... Sleazy Joe Biden is NOT my Duly-Elected President.! 🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸
Thanks for the in-depth analysis! I use an RSP spectrum analyzer (RSPdx hardware) daily and it works fantastic. Many improvements were made in v1.1 of the software vs the 1.0 version which you have here.
Just a couple of corrections - for some of the tests, you are using a 2khz span which means 200hz per division. So the sidebands from your signal generator are roughly at +/- 200hz from center, not 2khz. So at 21:40, the Rigol DSA-815 isn't showing them because of the 100hz RBW limitation of that machine. They are still there.
SO grateful to Steve Andrew for the software (he seems to have abandoned the project) and to you for these in-depth tests and explanations!
Great analysis and findings on the limitations and capabilities on various types of Spectrum Analyzers.
They've now become very compact affordable and prove themselves to be an indispensable tool for any amateur radio hobbyist or RF engineer. Keep up the great work.
Thank you ! this was a very good video . The first time I used the RSP analyzer , I shut it off in 5 minutes and called it junk because it did not have modulation type and audio.
I was comparing it to another SDR play program . ( SDR uno ) I have a lot of RF interference on my back deck in the 2 meter band. The noise floor with UNO was always locked onto -95 dbm. I took off the antenna from the RSP Play and it never changed . I put the SDR play into a dummy load and it was the same -95dm. I dumped that program and went to the RSP spectrum analyzer . I found a huge difference in the readings. If I put the SDR into a dummy load the noise floor dropped 25-30 dbm. I could move my antenna around and I could watch the noise floor move with the antenna. I could not with the SDR UNO. With this analyser I could find a place on my deck to place my antenna with the lowest noise floor.. Good luck doing that with UNO . I still have a high noise floor in the 2 meter band but at least I sniffed out a spot with a low noise floor so I can hear the local repeaters.
Really useful information. Thank you! I respect your attitude toward electrical engineering at your ages.
Excellent video. I've watched a lot of videos on Spectrum Analyzers and I finally think I understand RBW.
Thanks very much for explaining RBW in a way that it finally made sense to me.
Robert, K6FNI
Thank you very much for such a great tutorial.
Great video(s), would it be possible to use the RSP to test radio harmonics on HTs for instance? I assume I’d need some attenuators. Thanks!
Hi, I noticed when you were not experiencing the sidebands on your signal the noise floor was around the level of the sidebands e.g. around -80 to -90DB.
Great video.
Thanks for this. I have thought about putting my RSP into a shielded box, it seems it is not necessary though, given the excellent noise floor. Have you solved the mystery of the 1 MHz sidebands yet?
Cheers,
Thanks for your comment and question. I am convinced that the sidebands are being produced outside the RSP1A, i.e. they are due to a strong external signal interacting with a non-linearity outside the SDR that produces a modulated signal at these very low levels. These exist, of course, in almost all places outside of shielded labs, etc. but are often not noticed unless you are looking near the noise floor as we are in this case. One reason I am sure it is outside the RSP1A is that the Signal Hound SA44 displays almost exactly the same signals. They are not as obvious on standalone spectrum analyzers (like the Siglent, Rigol, or Instek) so it may be due to the computer connection (both the SDR and SA44 use USB to power and operate the hardware).
Excellent video, tnx fr the upload!
73 N8AUM
Great video Thanks for sharing your thoughts. How does it compare with the FFT of a siglent 1202x-E or Rigol 1054z . Thank you
In my opinion, the RSP Spectrum Analyzer is vastly superior to the FFT of either of those scopes. The RSP is not only technically superior, but also much easier to use.
@@tomtektest8042 Thank you for your opinion. Can't afford a Spectrum Analyzer yet. Will look into RSP option. First time I hear about RSP product and of course the software. Thanks again and look forward to more videos.
Hi.. and Thanks!
I have the Triarchy VSG6 and their Spectrum Analyzer. (The earlier 6GHz model)
The software is terrible IMHO. I had it functional and was able to apply the calibration files
in the original ToughBook (win 7 pro) laptop I had back when I originally purchased the Triarchy Tech devices.
But... It will not load the cal files on my new ThinkPad “portable workstation” (aka “laptop” 🙄)
Their support is just plain awful.
I DO like the Spike application for the SignalHound line.
The company is entirely US based and the hardware is produced here as well.
The tech support is incredibly good for an instrumentation company.
I am contemplating purchasing a spec analyzer and separate tracking generator
for a project I have in mind. The Signal Path and Comms Prepper TH-cam channels
both have very good review videos and they are both very reputable sources IMHO.
I also have an Agilent N9340b “handheld” spec analyzer.
It is excellent and durable... BUT .. the display is very difficult to read in anything other than
dim light environments. It goes to 3GHz, but most of my work is in public safety 2-way comms,
so I rarely go above 900mhz. The cost was far more than I felt comfortable spending at the time
($6695 with TG and pre-amp options). but I somehow justified it to myself. 🙄
I primarily Use it as a hobbyist and, now that I’m retired.. and I occasionally tune a duplexer or cavity for
friends and the occasional prior client. Definitely not worth it for what I am doing...
But... believe it or not... with the higher-tier tools available to me,
it always seems like I just reach for my “economy” DSA815tg.
It is lightweight (1/2 the weight of the Agilent), does not require a functional computer,
has a great (BRIGHT!) display and it is quite easy to use. (especially for knuckleheads like me 😉😷🤣)
AND... it was CHEAP (compared to the other solutions I own) at $1875 with TG option and Rigol soft case.
Might I suggest the BEST ACCESSORY for RF ?. It is by far the BEST investment I’ve made in the past decade.
The RF Industries “Unidapt” connector set. It is a “universal” conmector set that includes nearly every RF
connector (depending on the set you purchase.. they have 3 or 4 sets ranging from $60 - $550)
I won’t be able to do it justice here, so go and Google it. PLEASE 🐔
Two things I should mention:
absolutely purchase the “WHITE BRONZE” finish. (a few dollars more than
the nickel plated, but the finish will last longer and no issues with PIM / intermod).
and... take a look at their BLUE interconnect cables. While you can use your own,
you will get much more use out of the set when you do not have to sacrifice extra
connectors to interface with your own cables.
The “BLUE” Unidapt coax cables are made by Belden specifically for Unidaot.
It is a hybrid between the RG400 and RG58 cable types. Silver plated
stranded center conductor / silver-plated DOUBLE SHIELDING/ ultra flexible/
very nice strain relief boots installed / silver plated “Unidapt” specialty fittings installed on both ends.
(they mate directly with the connectors/ adapters that come with the sets)
The cables are 5’ and 6’ in length and cost around $22-35@. Compare that to my Pasternack and
other “high tier” cables and these are much nicer and a fraction of the cost.
Forgot... just a quick list of connector types in my “medium” Unidapt set (2x of each type)
N Male / N female / BNC male / BNC female / F male / F female / SMA male / SMA female
MCX male / MCX female / RCA “phono” male / RCA “phono” female / 7/16” DIN male and female
AND.... 6x “couplers” (threaded double female Unidapt on each side)
Thanks for your channel and videos!
I will be binge watching all weekend.
👍🏻 73 from NJ
The Salty Cracker Army is Legion
🧂🧂🧂🧂🇺🇸🇺🇸🇺🇸🧂🧂🧂🧂
Epstein did NOT kill himself.
And...
Sleazy Joe Biden is NOT my Duly-Elected President.!
🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸