Thx for the walkthru, well done and I love how you link and make due diligence on these products and link to the relevant parts, that a possible owner can benefit from.(golden) many other channels can learn from the "viewer perspective-awareness" you seem to suit your videos with. well done Andreas. +1 Don't have this Spectrum analyzer but were looking into it as an entry tool to just get familiar with this kind of class apparatus. at around 30 bucks delivered for this unit (no shell), alternatives are not hanging on the threes in this sub 100 bucks environment.
I used my R&S FSEA20 analyzers almost every day for a seven year period. I got pretty used to these high performance machines that had a noise floor of about -160 dBM at zero span. Made my job easy. These days those analyzers can be had for about 1500 bucks in good working order.
You are right. I see a lot of people buying these old instruments. They are a very good choice if you have enough space and maybe also some knowledge to use/repair them. For you, as a long-time user, this is a perfect fit and not comparable with such a cheap device...
I designed spectrum analyzers for Hewlett Packard as my first job out of collage in 1971. The group I worked in is now called Keysight. They were very expensive but I see you can buy one now for a few hundred dollars and get a spectrum analyzer that works to 22GHz. Wow. I worked on the log amplifier that had a dynamic range of 100dB. Loved this video. I think that this cheap analyzer is mixing the input down to DC but the filter is actually a bandpass with a bandwidth of about 250 KHz and a center frequency of about 200 KHz. Thus when you input a signal you see both the + and - image products of the mixer output spaced 400 KHz apart. The display occupies that plus the bandwidth of the filter so they call it 1 MHz. When the LO is tuned to the frequency of the input signal the output is DC and the filter blocks it so you see what looks like a notch in the output.
Yeah that's very plausible. Thank you! That both side bands are visible seemed obvious. But how is this avoided in the design of professional instrumentation?
@@LutzSchafer It gets very complicated as there are way more things to worry about than just the issue with this cheap spectrum analyzer. But for the question asked I will give a short reply. If you want to analyze .1 to 2.5 GHz, mix the input up to 3.6 GHz. Then the LO goes from 3.7 to 6.1GHz and the difference signal is 3.6 and the sum is 3.8 to 8.6 and can easily be filtered out. Then use another mixer to get the signal down to 300 MHz and another to get to 21MHz where I built the Log amp. These frequencies need to be carefully selected so that harmonics of the LO do not put spurious signals in band so they are picked more carefully that what I did in the above example. Hope this helps.
You could say that the Mixer is a Multiplier. If you remember your trigonometry: sin(a)* sin(b) = (cos(a − b) − cos(a + b))/2 This is why the sum and difference of frequencies appear. In practice the Mixer is not perfect and there are nonlinearities that generates also harmonics so you get N*a + M*b (with N and M integers). But the other frequencies and usually much attenuated with a good Mixer.
@@AndreasSpiess I understand that just putting a trigonometry formula in a video can scare people 😆 I'm not a RF guy at all but I find that part of electronics quite stimulating. I just wanted to add some extra for the curious ones that asked themselves "how does a mixer work?"...
wow this is so cool. I am starting to check out how to build a SDR radio telescope and one video used a cheap spectrum analyzer test the 21cm astronomy hydrogen line. This is a all new learning curve on making a homemade radio telescope using SDR software. 😎 thanks a lot.
Excellent video, as usual, thanks very much, Andreas. That German "Tiefpaßfilter" should be at least 24 years old as it is written "Tiefpassfilter" since 1996. Now I know what a spelling reform is good for.
Good video. I had a look at this cheap device a few weeks back, my mouse cursor hovered over the 'buy now' button. After watching this review i decided NOT to buy it, save up more money for a proper one. This video saved me $55 and disapointement. Thank you Andreas !!
If I understand everything correctly then this spectrum analyzer uses an low IF frequency of ~few hundred kHz, most spectrum analyzers use high IF that is higher than maximum frequency they can measure. Because of that it is going to see signals that are centered at LO +/- few hundred kHz and that's why there are 2 peaks when you measure signal of that handheld. That's very bad because some signals, like signal from that handheld will appear to occupy twice the bandwidth and have a weird notch in the middle as seen on the video.
Thanks for the video Andreas. My radio club bought a Rigol Spectrum analyser a few months ago and I wanted something similar for my little work bench and having found this on ebay thought it was a good little project ( I bought the naked board). I've only yesterday finished putting it into a case with N connectors and will be keen to try the new software. Love the cat on keyboard :-) Keep up the vid's, It's good to see a ham doing such a diverse range of topics.
Thank you Guy with a swiss accent. I visited Luzerne for 1 day. At night. It was okay. :) I want a spectrum analyzer. I don't have a use for it right off the top of my head but I would find a reason. Not swiss mentality but hey... this is internet.
I do not know a lot of bode diagrams. But the device has a built-in tracking generator. Mind the minimal frequency if you would like to use it for audio.
Another very useful video thank-you. 2 years on I was hoping perhaps you had covered the Tiny SA spectrum analyser but could not find it on your page. I would be very interested to know how you find it.
@@AndreasSpiess Thanks for the reply. I have seen some videos. I was interested in how you personally found them. I think they are worth a try at the price.
I am French. Can you confirm that the voice-over of this video is in English? I have a big doubt because I understood everything without problem! I have rarely seen a video of this quality on UA-cam, both technically and in terms of video editing and sound recording ... and with so much humor!
This is a very nice comment! Thank you. French nearly "killed" my career when I was young because of the bad grades. I only learned it when I worked in Cameroon... But since then I forgot most of it. Good that we can communicate in English.
Nice SA overview; i did think that you might add that one often uses a noise source, instead of a tracking generator, since it removes a couple of 'dependencies', but, that's a bit picky... i see that you mentioned the noise source right at the end! Sad, how often some inventive person's work becomes just one more source of a chinese company's income :-( When I was in Helsinki, i visited a showroom of "Finnish Design", showing off the truly-great breadth and quality of art, artisanship, and inventiveness of the people of this country of only 5.5 million people (a shameless plug for them! ), and, what do I see? A small group of mainland chinese (i recognised the mandarin language) , walking around, taking photographs of items... not just a 'snapshot', either, but pictures from every possible angle. Obviously, not just a 'tourist photo', they intended to go home, make a copy, and sell a few million. So, even when it's not 'visible', we may find the nice work of some German, Swiss, Canadian, Finn, at the heart of some chinese gear that is so inexpensive that we canpt avoid buying it...or, can we? Still, it would be a nice surprise for some German, or Swiss, ham person, to receive a few Euros/CHF in his bank or paypal, or 5€ in the post :-) !! itps just a thought....
I remember the 1980s where the Japanese did the same with our products. Nothing new. Switzerland still exists because we are very innovative. The same will happen again and again, I think. This is how the world moves. We were the leading country in textiles 100 years age... As you mention we can send these people a few Euros if we want. Like my patreons do it with this channel, for example.
Very good info..I subscribed and plan to watch more vids. I have added some external filters and a 30db wide band LNA on the input of mine. It has made the spectrum analyzer more useable. It’s still not great, but much better. I also did clean up the Power supply and did the mods going around on the net. I added a variable attenuator on the in and TG out along with the ext Amps. I packed it a nice shielded cabinet its not as good as a real network analyzer, but it is actually useful now. I actually made a selectable multi filter selection for different band widths. The stock internal filtering was pretty bad. I may try to do some more improvements? We will see? Too many pokers in the fire. Great channel. I enjoyed watching.
Andreas Spiess . Thank you sir. I will try to put together all my info on the mods i made. Its pretty much chicken scratch now, but i will try to compile it i to something intelligible. I will be watching and i will let the channel know when i have good information to share. Thank you for the warm welcome.
This is not ham channel. It focusses on the ISM usage of RF because only a very few of my viewers are HAMs. Maybe I can motivate a few ISM guys go get licensed...
Thanks very interesting. what would -77dBm be in (microwatts/meter squared) and (Volts/Meter) I have an cell tower in front of my house about 1350 feet away pointing right at my window it says: on an antenna search (Maximum signal strength RSRP -77 dBm) for antenna that's facing 287degrees North would like to know if radiation is high at my window. Thanks
You do not get absolute values because the influence of the antenna. But if a cell tower blasts in your direction you will have as very strong signal on the frequencies try use. BTW you find online calculators to convert dBm to Watt. As said, these are for cables. A typical cell tower easily emits 2kW where I live.
Thanks Andreas. I'm interested in testing an area to find out what radio frequencies and signal strengths are present. What would be the most cost-effective way to approach this problem?
@@AndreasSpiess How much would you need to spend on either of these technologies in order to get something reliable and useful? Do you have any brands/models to recommend?
Andreas I have done similar experiments with the same Banggood device. What struck me first was that the tracking generator produces more or less a square waveform. Presumably same is true for the LO since it uses the same chip. So the mixing products must contain odd harmonics of the LO. I also observed the dip when trying to display a single carrier tone. You have any idea what it's causing it? It almost looks like as if both side frequencies contribute to whatever is "measured". The symmetry kindof gives it away. BTW I like your cat :)
Viewer Allen Edwards below gives an explanation for the notch. Concerning square wave: You are right. But because the LO sweeps with the TG it (usually) does not see these harmonics. I mentioned that the Siglent has more filters. This is where some of them are. Its TG creates a sine...
I did not know it. But now I tried. Unfortunately I also was not successful. I tried to calibrate the SA and then measure the very same configuration. I would have expected to see 0 dBm across the spectrum. Unfortunately II did not see anything like that. :-(
Hi there Any chance for a help here I want to measure EMF There is a device that produces an EM radiation and I wanted to find out all the details about it Any chance what tools I would need Thx Also For radio frequency measuring Thx for getting back to me
I think you need to watch videos concerning EMF if you are interested in this topic. Spectrum analyzers only have a "trackung generator that produces a vers small signal at one particular (but moving) frequency. They are mainly made to show RF signals.
Hello Andrea, all, First, thank you for this demonstration. Just wondering how you would use the cheap spectrum analyzer to measure noise from magnetron @2.999997GHz in a room? I was aiming to use a dipole antenna on the input but shall I need filtering ? which sweep span do you suggest? any other advise? Thank you and wish you the best for 2021.
@@AndreasSpiess Did your's have a very weak signal? With the output connected back to the input the sweep is way down at -34 dB instead of at 0 dB like on the older one. Do I need to remove that resistor on the input? Actually I removed the resistor but it doesn't make any difference. I'm really disappointed in this newer model, the sensitivity is so poor that it's not much good as a spectrum analyzer unless you are dealing with transmitters close by.
Sorry, but isn't your conversion from -70dBm wrong at 2:00? -70dBm is 1X10-7 mW which is 0.0000001 mW (minus seven 'Bell's is minus seven orders of magnitude) You have one too many zeros.
Hi Andreas. I can see you plan to speak at ukw-tagung.org/vortraege/ this year but most of the lectures are in german and Mein Deutsch ist nicht sehr gut. Maybe there is a not very expensive gadget that can make conversation mode real time translate
The TinySA is much newer and definitively the better choice. And for sure not garbage. The HP has a really bad price/performance ratio for most of the usual work compared with these cheap devices...
@@AndreasSpiess ADF4351 VCO phase noise doesn't even come close to that of a YIG oscillator inside a good old HP spectrum analyzer. Unless you need a fancy computer interface, a HP8560/8561/8562/8563 or HP8566/8568 offers much better price/performance ratio.
If out of the box it can't find a narrowband transmitter right next to it then it is dangerous. That and the lack of supported software means this is a ripoff product, ripoff of the designer and ripoff of the consumer. Also that big notch in the middle of the spectrum is just plain wrong. Stay away.
Let's wait for Andreas' answer ... (but) If you go back you'll find re. "🤠" that he is/used to be a steampunk afficionado... (zurich maker faire 2017) 73 de 🚲
Best "organized" Vid in UA-cam! Please never give up your style of "summarization". -seems yet another piece of equipment where I have to know the result before I can measure it... let me check the improvements ;)
@@AndreasSpiess - Yes, definitely on of the best organized tec chanel's over YT. And there are no wrong miss leading or confusing procedures. It's Swiss prescision content!!!
Hi Andreas, some time ago I bought one of this chip device. I compared features wit a R&S in office lab: agree with your conclusion ... About SW, I tried to be in touch with the original designer but ( I can 100% understand why ) I did not receive an answer. Any way, googling and spent some time reading forum, I found Python driver and commands list ... ... but all is sleeping since "The job is not worth it"
Let me say thank you for this video Andreas. I had this same device from banggood sitting on my desk and couldn't get it to work, i will be going back to it now that i have a better understanding of it..thank again.
Thank you for wonderful explanation! I got exact image of this spectrum analyzer (LTDZ_35-4400M). I had interest in notch characteristics for CW (Continuous Wave) that 145.55MHz in your video. I checked the circuit diagram and I understood the mechanism of that. Following 2 things are the points of the notch: - The same idea of DCR (Direct Conversion Receiver) - The characteristics of RBW (Resolution Band-Width) filter About the DCR, when we apply the same frequency signal for RF (measurement signal) and LO (Local Oscillator) of the mixer (IAM81008), the mixer output become DC signal. And amplitude of the DC signal depend on the phase difference between RF and LO. However, RBW filter has DC block capacitors, so DC voltage doesn't reach to Logamp (AD8307) input pin. These DC block capacitors are the major reason of the notch characteristics. About the RBW filter, I simulated RBW filter (including DC block capacitors) that using LTspice. It had f0= 200kHz +/- 100kHz of bandpass filter characteristics. When we apply CW to the RF input, Logamp input will appear twin peaks of signal because RBW filter has bandpass characteristics. I think your demonstration of 145.55MHz CW agree to my estimation. Because I seen the frequency difference between peak to peak is 400kHz (=200kHz*2) in your video. I got additional idea from these consideration. It is TG (Tracking Generator) offset frequency. In DCR idea, if LO and TG sweep with the same frequency, mixer output will be DC voltage. In this spectrum analyzer, we cannot see frequency spectrum because DC block capacitor blocks DC voltage. So in this spectrum analyzer, TG (become RF signal) and LO frequency should have offset value such as 200kHz.
Amazing explanation! I was trying to figure out what was causing the notch. This design was used to simplify the mixing stage, using just one, in contrast to "conventional", or "real" spectrum analyzers that uses two or more mixing stages, right?
About as expected for $50. But I would just go buy used SA off ebay. You can get some really incredible ones for very cheap. Devices which used to cost $150,000 can be purchased for only ~$500. Lesson learned: expensive high end lab test equipment doesn't retain any value and depreciates worse than even the worst automobile.
I didn't quite understand where that false notch comes from. It is also quite prominent at the more detailed scan. Edit: Lister Dave's comment bellow explains it nicely. There is C29 capacitor that removes the very DC we want to measure. I Think that C18 may do the same. ua-cam.com/video/PRsaGEk-EsQ/v-deo.html&lc=UgyDM9iflCNIOa0WzXV4AaABAg.95NRn9Qnwem95NTJCzMq0w
Unfortunatley you do not find old instruments in all countries. They are often sold in the US, and transport can become quite a problem for such heavy things :-(
You saved me $50. I might have bought this for fun. Also from the comments I learned that the Germans have abandoned the old version of "ss" which I learned back in the 1970-s. The "sharp s" which it was called here. (Where is it on my keybord?)
Thx for the walkthru, well done and I love how you link and make due diligence on these products and link to the relevant parts, that a possible owner can benefit from.(golden)
many other channels can learn from the "viewer perspective-awareness" you seem to suit your videos with.
well done Andreas. +1
Don't have this Spectrum analyzer but were looking into it as an entry tool to just get familiar with this kind of class apparatus.
at around 30 bucks delivered for this unit (no shell), alternatives are not hanging on the threes in this sub 100 bucks environment.
You are right: For sure it is good as an education device. And knowing this technology is important for many projects
I used my R&S FSEA20 analyzers almost every day for a seven year period. I got pretty used to these high performance machines that had a noise floor of about -160 dBM at zero span. Made my job easy. These days those analyzers can be had for about 1500 bucks in good working order.
You are right. I see a lot of people buying these old instruments. They are a very good choice if you have enough space and maybe also some knowledge to use/repair them. For you, as a long-time user, this is a perfect fit and not comparable with such a cheap device...
I was about to buy one of these 50 dollars spectrum analyzer, but after seeing this video I changed my mine. Thanks Andreas Spiess
You are welcome!
Thank you for yet another very interesting video! The testing, the explanations and the conclusions at the end are all very valuable. Thank you!
You are welcome!
I designed spectrum analyzers for Hewlett Packard as my first job out of collage in 1971. The group I worked in is now called Keysight. They were very expensive but I see you can buy one now for a few hundred dollars and get a spectrum analyzer that works to 22GHz. Wow. I worked on the log amplifier that had a dynamic range of 100dB.
Loved this video. I think that this cheap analyzer is mixing the input down to DC but the filter is actually a bandpass with a bandwidth of about 250 KHz and a center frequency of about 200 KHz. Thus when you input a signal you see both the + and - image products of the mixer output spaced 400 KHz apart. The display occupies that plus the bandwidth of the filter so they call it 1 MHz. When the LO is tuned to the frequency of the input signal the output is DC and the filter blocks it so you see what looks like a notch in the output.
This is when somebody understood the math behind the view... congrat!
Yeah that's very plausible. Thank you! That both side bands are visible seemed obvious. But how is this avoided in the design of professional instrumentation?
@@LutzSchafer It gets very complicated as there are way more things to worry about than just the issue with this cheap spectrum analyzer. But for the question asked I will give a short reply. If you want to analyze .1 to 2.5 GHz, mix the input up to 3.6 GHz. Then the LO goes from 3.7 to 6.1GHz and the difference signal is 3.6 and the sum is 3.8 to 8.6 and can easily be filtered out. Then use another mixer to get the signal down to 300 MHz and another to get to 21MHz where I built the Log amp. These frequencies need to be carefully selected so that harmonics of the LO do not put spurious signals in band so they are picked more carefully that what I did in the above example. Hope this helps.
By the way, the HP8566 weighed 100 pounds.
I suggest to watch the Signalpath video. There you see exactly what Allen explains: ua-cam.com/video/Fn7uaEVeOPk/v-deo.html
You could say that the Mixer is a Multiplier.
If you remember your trigonometry: sin(a)* sin(b) =
(cos(a − b) − cos(a + b))/2
This is why the sum and difference of frequencies appear.
In practice the Mixer is not perfect and there are nonlinearities that generates also harmonics so you get N*a + M*b (with N and M integers). But the other frequencies and usually much attenuated with a good Mixer.
And if you want to know how to multiply signals:
ua-cam.com/video/7nmmb0pqTU0/v-deo.html
You are, of course, right. For my videos I usually need more time to "leave things out" than to "put things in"...
@@AndreasSpiess I understand that just putting a trigonometry formula in a video can scare people 😆
I'm not a RF guy at all but I find that part of electronics quite stimulating.
I just wanted to add some extra for the curious ones that asked themselves "how does a mixer work?"...
BTW: Your link points to a very good channel...
Before Spectrum Analyzers we had Frequency Selective Voltage meters. Aka the most expensive AM Radio's in the world. Cool Video yet again Sir.
This was probably many years ago... But they did the job. And many awesome projects were done in this time.
wow this is so cool. I am starting to check out how to build a SDR radio telescope and one video used a cheap spectrum analyzer test the 21cm astronomy hydrogen line.
This is a all new learning curve on making a homemade radio telescope using SDR software. 😎 thanks a lot.
Check the newest link in the description before you buy a TinySA. There is a new version available.
@@AndreasSpiess I checked it out and ordered a: tinySA ULTRA 100k-5.3GHz Hand held tiny Spectrum Analyzer + 4" TFT LCD +Battery. Thank you very much.
Excellent video, as usual, thanks very much, Andreas. That German "Tiefpaßfilter" should be at least 24 years old as it is written "Tiefpassfilter" since 1996. Now I know what a spelling reform is good for.
Interesting. Frequencies still are the same today...
Good video. I had a look at this cheap device a few weeks back, my mouse cursor hovered over the 'buy now' button.
After watching this review i decided NOT to buy it, save up more money for a proper one. This video saved me $55 and disapointement. Thank you Andreas !!
You are welcome. Decisions like that are the purpose of this video...
If I understand everything correctly then this spectrum analyzer uses an low IF frequency of ~few hundred kHz, most spectrum analyzers use high IF that is higher than maximum frequency they can measure. Because of that it is going to see signals that are centered at LO +/- few hundred kHz and that's why there are 2 peaks when you measure signal of that handheld. That's very bad because some signals, like signal from that handheld will appear to occupy twice the bandwidth and have a weird notch in the middle as seen on the video.
Exactly! But for 50 dollars an IF above 4GHz including filters is probably still not possible.
TLDR It works but you get what you paid for. Thorough video again by Andreas!
I still think, we get quite a lot for 50 dollars. Those new AD chips really make it easy to build interesting things...
Thanks for the video Andreas. My radio club bought a Rigol Spectrum analyser a few months ago and I wanted something similar for my little work bench and having found this on ebay thought it was a good little project ( I bought the naked board). I've only yesterday finished putting it into a case with N connectors and will be keen to try the new software. Love the cat on keyboard :-) Keep up the vid's, It's good to see a ham doing such a diverse range of topics.
For HAMs a nanoVNA maybe is a better choice to measure antennas and filters. I hope your SA will do the job.
Cat found the best spot for a snap :D
This is why I need three monitors. One is no more usable...
This was a great video. You explained everything so well. Thanks!
You are welcome!
Yes, yes Andreas is a good communicator
Very usefull tutorial about Spectrum Analyzer .. the natural sinewave generator is a must and cat is paying atention even "sleeping".
Yes, she usually does not sleep. She just "rests"...
Tnx for nice explenation! Got it: the FIXED Resolution Band Width!
:-)
I understood the first and the last couple of minutes. Most important component is a furry oscillator.
"Furry oscillator"! Man, I almost spit my coffee against the screen laughing … have to remember that one! :-) :D
@Malt :-)) You got all you need, I think ;-)
Thank you Guy with a swiss accent. I visited Luzerne for 1 day. At night. It was okay. :) I want a spectrum analyzer. I don't have a use for it right off the top of my head but I would find a reason. Not swiss mentality but hey... this is internet.
I also have bought a few things like that ;-)
Very good job Andreas, nice presentation and very useful, tanks you...!
Glad you enjoyed it!
Probably my favorite video among all your great quality tutorials! But what does the VBW indication on your Siglent screen correspond to?
The explanation is here: www.siglenteu.com/application-note/spectrum-analyzer-basics-bandwidth/
Perhaps it is mentioned, but I didn't got it. Can this analyzer work as a tracking generator, e.g. for bode plotting?
I do not know a lot of bode diagrams. But the device has a built-in tracking generator. Mind the minimal frequency if you would like to use it for audio.
wonderful explanation on a Spectrum analyzer. Thanks ✨✌😊
You are welcome!
Another very useful video thank-you. 2 years on I was hoping perhaps you had covered the Tiny SA spectrum analyser but could not find it on your page. I would be very interested to know how you find it.
It seems to be a good device. There are a few very instructional videos on UA-cam. I think they are from the programmer of the firmware.
@@AndreasSpiess Thanks for the reply. I have seen some videos. I was interested in how you personally found them. I think they are worth a try at the price.
@@acestudioscouk-Ace-G0ACE I have a Siglent Spectrum Analyzer on my desk. So I did not use the tinySSA a lot.
Excellent educational presentation, bromigo!
Thank you!
I LOVE the pointer.
:-)
I like that sweet hand! That helps a lot!!!!!!!!
:-)
I am French. Can you confirm that the voice-over of this video is in English? I have a big doubt because I understood everything without problem!
I have rarely seen a video of this quality on UA-cam, both technically and in terms of video editing and sound recording ... and with so much humor!
This is a very nice comment! Thank you. French nearly "killed" my career when I was young because of the bad grades. I only learned it when I worked in Cameroon... But since then I forgot most of it. Good that we can communicate in English.
Keep watching Andreas and prepare to learn a lot!
@@AndreasSpiess Oh mon dieux c'est incroyable
Nice SA overview; i did think that you might add that one often uses a noise source, instead of a tracking generator, since it removes a couple of 'dependencies', but, that's a bit picky... i see that you mentioned the noise source right at the end!
Sad, how often some inventive person's work becomes just one more source of a chinese company's income :-( When I was in Helsinki, i visited a showroom of "Finnish Design", showing off the truly-great breadth and quality of art, artisanship, and inventiveness of the people of this country of only 5.5 million people (a shameless plug for them! ), and, what do I see? A small group of mainland chinese (i recognised the mandarin language) , walking around, taking photographs of items... not just a 'snapshot', either, but pictures from every possible angle. Obviously, not just a 'tourist photo', they intended to go home, make a copy, and sell a few million.
So, even when it's not 'visible', we may find the nice work of some German, Swiss, Canadian, Finn, at the heart of some chinese gear that is so inexpensive that we canpt avoid buying it...or, can we? Still, it would be a nice surprise for some German, or Swiss, ham person, to receive a few Euros/CHF in his bank or paypal, or 5€ in the post :-) !! itps just a thought....
I remember the 1980s where the Japanese did the same with our products. Nothing new. Switzerland still exists because we are very innovative. The same will happen again and again, I think. This is how the world moves. We were the leading country in textiles 100 years age...
As you mention we can send these people a few Euros if we want. Like my patreons do it with this channel, for example.
Very good info..I subscribed and plan to watch more vids. I have added some external filters and a 30db wide band LNA on the input of mine. It has made the spectrum analyzer more useable. It’s still not great, but much better. I also did clean up the Power supply and did the mods going around on the net. I added a variable attenuator on the in and TG out along with the ext Amps. I packed it a nice shielded cabinet its not as good as a real network analyzer, but it is actually useful now. I actually made a selectable multi filter selection for different band widths. The stock internal filtering was pretty bad. I may try to do some more improvements? We will see? Too many pokers in the fire. Great channel. I enjoyed watching.
Welcome aboard the channel! You invested quite some effort¨. Maybe you document it for others to follow?
Andreas Spiess . Thank you sir. I will try to put together all my info on the mods i made. Its pretty much chicken scratch now, but i will try to compile it i to something intelligible. I will be watching and i will let the channel know when i have good information to share. Thank you for the warm welcome.
Please a video about using SDR as Spectrum analyser :)
Maybe later...
@@AndreasSpiess Yes please
Thank you for another great video. I wish to see more episodes related to RF signals and ham radio. Vy 73!
This is not ham channel. It focusses on the ISM usage of RF because only a very few of my viewers are HAMs. Maybe I can motivate a few ISM guys go get licensed...
Grüezi! I enjoyed the video from beginning to end. I still use my Tektronix 2711 and I will not buy the one from Banggood.
Probably not a bad decision ;-)
YOU ARE AMAZING ! thanks for good content
You are welcome!
which spectrum analyzer is recommended for identifying chemical elements of a material (by optical, by thermal, ...)?
I have no idea :-(
Thanks very interesting. what would -77dBm be in (microwatts/meter squared) and (Volts/Meter) I have an cell tower in front of my house about 1350 feet away pointing right at my window it says: on an antenna search (Maximum signal strength RSRP -77 dBm) for antenna that's facing 287degrees North would like to know if radiation is high at my window. Thanks
You do not get absolute values because the influence of the antenna. But if a cell tower blasts in your direction you will have as very strong signal on the frequencies try use.
BTW you find online calculators to convert dBm to Watt. As said, these are for cables.
A typical cell tower easily emits 2kW where I live.
I defenately liked this one ! Excellent and well described !
Thank you!
The cat was really impressed
:-))
If in doubt, add cat. It never fails to improve a video.
You are right, of course ;-)
Danke fürs Erklären! Haben Sie auch noch einen deutschen Kanal? Mit Englisch tue ich mich ein bisschen schwer.
Bitte, gern geschehen. Und nein, ich habe kaum Zeit für diesen Kanal :-(
Thank you again for the high quality video! I was thinking about getting one of these, I'm glad to know exactly what the limitations are.
You are welcome! This was exactly the reason for that video...
The limitations are not what you see in the video.
You need additional white noise generator, or use a happy cat instead. ( What Andreas demonstrated with Mishka at the end of the video )
Not exactly whie noise what she produces...
@@AndreasSpiess Perhaps better suited as a tracking generator for birdies detection.
Thanks Andreas. I'm interested in testing an area to find out what radio frequencies and signal strengths are present. What would be the most cost-effective way to approach this problem?
A spectrum analyzer is good. Or an SDR radio.
@@AndreasSpiess How much would you need to spend on either of these technologies in order to get something reliable and useful? Do you have any brands/models to recommend?
Andreas I have done similar experiments with the same Banggood device. What struck me first was that the tracking generator produces more or less a square waveform. Presumably same is true for the LO since it uses the same chip. So the mixing products must contain odd harmonics of the LO. I also observed the dip when trying to display a single carrier tone. You have any idea what it's causing it? It almost looks like as if both side frequencies contribute to whatever is "measured". The symmetry kindof gives it away. BTW I like your cat :)
Viewer Allen Edwards below gives an explanation for the notch. Concerning square wave: You are right. But because the LO sweeps with the TG it (usually) does not see these harmonics. I mentioned that the Siglent has more filters. This is where some of them are. Its TG creates a sine...
Very nice and explorative video. Did you try the snasharp software???
I did not know it. But now I tried. Unfortunately I also was not successful. I tried to calibrate the SA and then measure the very same configuration. I would have expected to see 0 dBm across the spectrum. Unfortunately II did not see anything like that. :-(
That whistling bounced off my walls and really creeped me out.
Very informative presentation - The software WinNWT4 is not very convenient - please can you give me a lead to the other software. Thanks
Unfortunately, I do not have another because I do not use the device regularly.
Маленькая рука-указатель - супер! :)
Thank you!
Hi there Any chance for a help here I want to measure EMF There is a device that produces an EM radiation and I wanted to find out all the details about it Any chance what tools I would need Thx
Also For radio frequency measuring Thx for getting back to me
I think you need to watch videos concerning EMF if you are interested in this topic. Spectrum analyzers only have a "trackung generator that produces a vers small signal at one particular (but moving) frequency. They are mainly made to show RF signals.
thanks
Welcome!
at 2:03 -70dbm = 0.0000001mw (6 Zeros) not 0.00000001mw. every -10dbm equals a factor of 10. good video otherwise
You are right. Thanks!
My question is, Because of the frequency ranging from 35 MHz to 4.4 GHz is this unit any good for audio( 50Hz to 20KHz ) analysis?
Thank you
No. It does not work for audio. You can use a soundcard and software for audio.
@@AndreasSpiess thanks 🙏
Thanks Andreas, I learned at least basics by your nice video. By the way I loved your cat :-D
Thank you! And I will tell her...
@@AndreasSpiess Purrfekt 😃
LOL, the Swiss guy is driving my Germany wife crazy with his whistle.
I hope not ;-)
What about using the HackRF One which goes up to 6 GHz?
Because the SDR receivers have a small coverage of a few MHz they are very slow. And sometimes only 8 or 10 bit. Which is not a lot of dynamic range.
@@AndreasSpiess Thanks for the reply.
Hello Andrea, all,
First, thank you for this demonstration. Just wondering how you would use the cheap spectrum analyzer to measure noise from magnetron @2.999997GHz in a room?
I was aiming to use a dipole antenna on the input but shall I need filtering ? which sweep span do you suggest? any other advise?
Thank you and wish you the best for 2021.
I do not know. Never used magnetrons.
@@AndreasSpiess ;-) microwave oven for instance !
What does the device say about the spectrum of the cat noise?
Unfortunately it does not cover those low frequencies ;-)
@@AndreasSpiess so, you need a faster cat ... or a slower analyzer.
Someone know maybe how to calibrate this device?
Nice item
🙂
Yes!
Where did you find the adf4351 spectrum analyzer schematic? I've search and searched but can't find that one anywhere.
alloza.eu/david/WordPress3/wp-content/uploads/2019/04/schematics.pdf
@@AndreasSpiess Did your's have a very weak signal? With the output connected back to the input the sweep is way down at -34 dB instead of at 0 dB like on the older one. Do I need to remove that resistor on the input? Actually I removed the resistor but it doesn't make any difference. I'm really disappointed in this newer model, the sensitivity is so poor that it's not much good as a spectrum analyzer unless you are dealing with transmitters close by.
Mine was higher, slightly below 0dB. But I do not remember the exact values. -34dBm seems to be very low. Defective?
1:52 Grützi Andreas, one zero too much.
-70 dBm = 1*10^-7 mW = 0.0000001 mW 🙂
Thank you for the correction!
Sorry, but isn't your conversion from -70dBm wrong at 2:00?
-70dBm is 1X10-7 mW which is 0.0000001 mW
(minus seven 'Bell's is minus seven orders of magnitude)
You have one too many zeros.
I am not sure why I even watched it till the end. But I am stoned as fucked
YOU SAVED ME 50€ FOR THIS BOX, THANK YOU VERY MUCH :-)
Glad I could help!
Do you think the RF Explorer 3G could be a good step up at US$270?
I do not know. There is a comment of an owner below.
thank you mr. Andreas! for realtime scan narrow freqs, doesn´t work!
Maybe. I do not know. The filter bandwidth anyway is not narrow.
Brown noise source @ 21:09 ;D
:-))
I found some shrooms that allow me to see electrical signals
Good for you. Use it to earn money!
Lets analyze the purring next....
You can do it with an ESP32. Not expensive...
@Arpad Toth long range, it homes in on cats...
TinySA please! (said with russian accent)
I have no plans with the TinySA for the moment.
@@AndreasSpiess Any videos from you is appreciated. And "for the moment" give some hope!
+1 for vna
:-)
Nano VNA or Nano VNA "V2"? :p
We will see when I get a V2, The normal is not good enough for me.
@@AndreasSpiess Eh eh eh not surprised it catched your curiosity already.
cute little hand,haha
:-)
Hi Andreas. I can see you plan to speak at ukw-tagung.org/vortraege/ this year but most of the lectures are in german and Mein Deutsch ist nicht sehr gut. Maybe there is a not very expensive gadget that can make conversation mode real time translate
This is an old speech from 2020. So far there are no further plans...
Yeah sorry, I lost you on the third zero.
No problem...
@@AndreasSpiess I've made better jokes. Awesome video as always, thank you. More LoRa stuff please!
So basically, garbage compared to TinySA, which is garbage compared to HP856x.
The TinySA is much newer and definitively the better choice. And for sure not garbage. The HP has a really bad price/performance ratio for most of the usual work compared with these cheap devices...
@@AndreasSpiess ADF4351 VCO phase noise doesn't even come close to that of a YIG oscillator inside a good old HP spectrum analyzer.
Unless you need a fancy computer interface, a HP8560/8561/8562/8563 or HP8566/8568 offers much better price/performance ratio.
What is the cat-spectrum.... 🤪
:-)
😘THE SLEEP CAT
:-)
Hallo Andreas auf them home page vom DL4JAL ist eines beschriebung www.dl4jal.eu/nwt4x/nwt4000.html
Vielen Dank für den Link!
10$ SDR much better than this weird thing
Do not forget: You also need a tracking generator.
If out of the box it can't find a narrowband transmitter right next to it then it is dangerous. That and the lack of supported software means this is a ripoff product, ripoff of the designer and ripoff of the consumer. Also that big notch in the middle of the spectrum is just plain wrong. Stay away.
like for cat :-) Mine is not as loud as yours :-)
I will tell her ;-)
Spectrum Analysis are handy. I miss having one. Use a mask on trips mate.
I do not fear too much to get ill. Usually I am not the first ;-)
My cat is a 1KHz detector, he came running, meowing every time you whistled. :D
Mine too! She doesn’t like this video :)
Thank you as my cat whined when he whistled and I did not know why but now do.
Sorry for that, guys!
@@AndreasSpiess It was kinda funny, he never comes running when I whistle, I must be off tune.
@Green Steve: My natural authority over small animals? ;-)
Lab cat. Very important. More valuable than the cheapie spectrum analayzer. Thank you for an informative video.
And also more expensive ;-)
and sometimes cats can be used as an ESD generator.... although usually when you weren't planning on it. :-)
5:48 _natural sine wave generator_ 😄
1570 Hz (by Android apk) ;o)
So it was a bit over the 1k signal...
Freaked my dog out
Wow. I understood how a Spectrum Analyzer is working and what it's for. In some 20 minutes. Thanks!
You are welcome!
@@AndreasSpiess BTW, Andreas (du ?), is the hat simply part of your personal style, or is it a kind of "Tracht"?
Let's wait for Andreas' answer ...
(but) If you go back you'll find re. "🤠" that he is/used to be a steampunk afficionado... (zurich maker faire 2017) 73 de 🚲
@@lohikarhu734 It's an 'ensemble' together with the 'lederhose'. Very common in alpine countries... ;-)
@@reinholdu9909 Steampunk :-)
Best "organized" Vid in UA-cam! Please never give up your style of "summarization". -seems yet another piece of equipment where I have to know the result before I can measure it... let me check the improvements ;)
Should improve the dynamic range...
Andreas tnx... btw:YOU (and QO-100 :) are driving me now to finally go for a HAM licence ...keep up the good work "in style" (=your's :)
@@AndreasSpiess - Yes, definitely on of the best organized tec chanel's over YT. And there are no wrong miss leading or confusing procedures. It's Swiss prescision content!!!
Awsome work and chanel. Thank you for your dedicated work. For this present moment the great tool is tinySA Ultra.
Amazing how cheap things can be when the core functionality can be implemented in software.
And excellent chips can be bought from Analog Devices for nothing...
NWT4000 DOES NOT RECOGNIZE THE LTDZ 35MHZ 4400MHZ SPECTRUM ANALYZER?
Thank you so much Andreas!! Lovely video. Thanks for your time.
yes, he has very cool videos
You are welcome!
Hi Andreas, some time ago I bought one of this chip device. I compared features wit a R&S in office lab: agree with your conclusion ...
About SW, I tried to be in touch with the original designer but ( I can 100% understand why ) I did not receive an answer. Any way, googling and spent some time reading forum, I found Python driver and commands list ...
... but all is sleeping since "The job is not worth it"
I tried to reach the author too with no success. The software could be so much more improved.
your left hand is really small, you know
Let me say thank you for this video Andreas. I had this same device from banggood sitting on my desk and couldn't get it to work, i will be going back to it now that i have a better understanding of it..thank again.
I hope it will work for you.
Thank you for wonderful explanation!
I got exact image of this spectrum analyzer (LTDZ_35-4400M).
I had interest in notch characteristics for CW (Continuous Wave) that 145.55MHz in your video.
I checked the circuit diagram and I understood the mechanism of that.
Following 2 things are the points of the notch:
- The same idea of DCR (Direct Conversion Receiver)
- The characteristics of RBW (Resolution Band-Width) filter
About the DCR, when we apply the same frequency signal for RF (measurement signal) and LO (Local Oscillator) of the mixer (IAM81008), the mixer output become DC signal. And amplitude of the DC signal depend on the phase difference between RF and LO.
However, RBW filter has DC block capacitors, so DC voltage doesn't reach to Logamp (AD8307) input pin.
These DC block capacitors are the major reason of the notch characteristics.
About the RBW filter, I simulated RBW filter (including DC block capacitors) that using LTspice.
It had f0= 200kHz +/- 100kHz of bandpass filter characteristics.
When we apply CW to the RF input, Logamp input will appear twin peaks of signal because RBW filter has bandpass characteristics.
I think your demonstration of 145.55MHz CW agree to my estimation.
Because I seen the frequency difference between peak to peak is 400kHz (=200kHz*2) in your video.
I got additional idea from these consideration.
It is TG (Tracking Generator) offset frequency.
In DCR idea, if LO and TG sweep with the same frequency, mixer output will be DC voltage.
In this spectrum analyzer, we cannot see frequency spectrum because DC block capacitor blocks DC voltage.
So in this spectrum analyzer, TG (become RF signal) and LO frequency should have offset value such as 200kHz.
Amazing explanation! I was trying to figure out what was causing the notch. This design was used to simplify the mixing stage, using just one, in contrast to "conventional", or "real" spectrum analyzers that uses two or more mixing stages, right?
About as expected for $50. But I would just go buy used SA off ebay. You can get some really incredible ones for very cheap. Devices which used to cost $150,000 can be purchased for only ~$500. Lesson learned: expensive high end lab test equipment doesn't retain any value and depreciates worse than even the worst automobile.
You are rright. Especially spectrum analyzers. The Siglent is also only 3000 Euros for 3.2GHz. Costed also a fortune a few years back ;-)
Kind of neat but that false notch renders the device useless in my opinion. Better to buy an old second hand SA. Thanks for the video Andreas 👍
I didn't quite understand where that false notch comes from. It is also quite prominent at the more detailed scan.
Edit: Lister Dave's comment bellow explains it nicely. There is C29 capacitor that removes the very DC we want to measure. I Think that C18 may do the same.
ua-cam.com/video/PRsaGEk-EsQ/v-deo.html&lc=UgyDM9iflCNIOa0WzXV4AaABAg.95NRn9Qnwem95NTJCzMq0w
Unfortunatley you do not find old instruments in all countries. They are often sold in the US, and transport can become quite a problem for such heavy things :-(
You saved me $50. I might have bought this for fun. Also from the comments I learned that the Germans have abandoned the old version of "ss" which I learned back in the 1970-s. The "sharp s" which it was called here. (Where is it on my keybord?)
AFAIK it is still on their keaboard. We Swiss never needed it ;-)
I love the little 🖐, pointing out things 😂
:-)
Me too. Where did you buy it?
Relearned the term "tracking generator" from school, but these days you might as well get an SDR in that price range.
As I mentioned, the SDRs are not exactly the same. If you want one with transmit you are in a higher proce range.