Thank you for this series. Nobody at work has a complete idea how to use these or when to trust them but they are more useful and trustworthy than the software data collection system which is always troublesome while these guys just work if you know how to operate them.
The zero beat (0Hz tone) not only is not weird or fictitious but its existence is essential and the first clue that your SA is healthy (if you are looking at buying a used SA, not having a 0Hz tone is the first clue that the unit is defective). This is the leakage of the first LO at 2.1214GHz (in your particular SA, 8591E) through the first converter that passes through the second converter and appears as 0Hz after it is down-converted in two stages. That's why it is called LO feed-through. If you dont see it, the instrument's LO is defective. It exists in ALL swept frequency spectrum analyzers of any brand and any model, old or new.
I've always seen one. nice clue about a heathy one having it. any idea what the third conversion (down to 8khz for 30hz rbw) filter design looks like. can't find any schematics for that card. is it discrete or dsp?
Thanks for doing this video. I have the exact same SA but mine has the tracking gen also. As per your earlier video I was cued to check my internal lithium backup battery. Mine was original from January 1995 (date was written on the battery) and it still measured good! I changed it anyway and I did not loose the calibration values (the supercap did its job). I have not explored all the fine details on this SA so hope you will get into some of those in future videos.
Nicely done and a timely series now with more affordable spectrum analyzer options easily accessible. "Spectrum analyzers are strange." LOL! Yep, cool and strange at the same time. It's great that you call out these oddities.
I have a 8591EM without the built-in tracking generator, I also have a HP8444A w/o opt 059. ?? Is there a way to use tracking in another way that you know of. You are my HP vintage equipment go to. Before the 8444A your guidance was to use the generator from my Tiny SA and now I want to try this. I Habs tried sweeping a 6m low pass filter with my 8601A which worked pretty good. BTW all of my HP equipment that I have purchased was because of your videos, Thank you. (I'm a 76 year old experimenter and licensed ham that should have started 50+ years ago. Thank you for all you have taught me)
The data spectrum analyzers display would great for pdn analysis. But I'm not sure how (if) I would want to connect the input of a sa to a high current power plane. (Up to 400 amps in the specific case I'm working on)
Thanks IMSAI Guy! I just acquired an HP 8557A in a 182T display. Right off the bat the only thing I know that is wrong with it is that it has no sweep. I have never used a spectrum analyzer before. Is this video applicable to analog sweep SAs like the 8557A? For example, will an analog sweep SA also display negative Hz peaks?
I'm glad I saw this video. I just purchased the sencore SG 80. I'm looking for something to measure the RF output. Does the spectrum measure microvolts? I know there are RF power meters but the spectrum can do much more. I was just curios about the micrvolts(uV) After watching this video. I now have better understanding about spectrum analyzers. Thank you for your time.
Great Channel. In the case of Looking at a 50 watt rf radio signal to see the harmonics, with the attenuated rf coming out of a bird sampler at -40 db, wouldn't any harmonics present also be attenuated -40 db? Possibly causing the harmonics to be lowered to the noise floor and be rendered not visible?
I don't know the design of the bird samplers. but samplers I have build myself are not flat with frequency as are attenuators. One would sweep the sampler and determine the frequency response.
Thanks bro that was really neat. So what’s a good price for that particular model? What if I were to be able to find one from a guy that is retiring or that’s gonna give me a pretty good deal on it versus what’s the every day price?
@@IMSAIGuy wow I think I’ll take yours for 200, Alex (Alex Trebek). If one were an ignoramus and wanted to purchase new; cheapest decent comparable model that’s not a piece of garbage? Hopefully under 1k
this particular SA already has a blocking capacitor at the input (47nF or 100nF, cannot remember exactly) it is rated at 25V but can handle more than that...so it's not that scary if you have some DC as long as it is not like 400V!
Superb video, many thanks - also for all other brilliant vids on your channel👍🏻This fundamentals helps me now better to understand my FFT function on my scope, even when it's might not really comparable with the performance of an analyzer (especially by using a R***l 1074Z 😉) P.S.: Like the manner of your vids and i'll certainly stay tuned - very educationally 🎯🏆👏🏻
The terminology is "Y as a function of X" or "Y vs. X" as dictated by mathematical standards. You had it backwards. Below is correct. Oscilloscope: Amplitude as a fn. of time, or "Amplitude vs. Time" Spectrum Analyzer: Amplitude as a fn. of frequency, or "Amplitude vs. frequency"
I suggest you look at the simple explanations first. The word "versus" can mean "compared with". The spectrum analyzer does not graph a mathematical function. it plots two data points. so frequency compared to amplitude or amplitude compared to frequency are equivalent. A graph of the days temperature would be described as the hour vs temperature or the thermometer reading vs the time of day. I don't think anyone would say the temperature as a function of the time. I try to teach things in simple terms to reach a broad audience. (2,3) (4,5) (1,5) plotted could be x vs y or y vs x, it doesn't matter, or use term plotted 'against'
The first thing to find out is the price. Is it affordable or is it a rip off? With excellent oscilloscopes selling for lesss than $400, an excellent spectrum analyzer should also be in that price range.
I wish spectrum analyzers were at $400 but they seem be >$1000. Supply and demand I guess. There are some really nice units by Siglent. I love the used market and picked up this SA for $250.
Not exactly sure about your question, but here is what I think you are asking. Acoustic is in the frequency range of 10 Hz - 20,000 Hz. There are spectrum analyzers that can operate at those frequencies. Most RF analyzers have a minimum frequency of 10,000 or 100,000 Hz.
the 8921 spectrum analyzer is very basic. the 8591 is way better in specs and usability. however, the 8921 has a tracking generator that makes it much better than the 8591 in in certain tasks. the 8591 did have an option for a tracking generator.
@@IMSAIGuy My needs are relatively basic- ham radio tx tinkering. I'm looking to purchase an 8921a and know you have this instrument so would have a good grasp of the two units capabilities. I'm coming on board as a patron for all the content you do.
@@cl5ltd What you might be looking for is a radio service monitor or communications service monitor. The HP8920 and 8921 or IFR1500 IFR1200 or Marconi there are German ones too. They are multipurpose. But you can do a lot with a simple generator and RF voltmeter.
@@IMSAIGuy Yes, a comms test set is what i'm moving towards and know of a 8921a, IFR1200S & Marconi 2955 for sale at present- all about same price, all in Queensland. The HP seems to be more modern even if from much the same era and is well built gear.
@@cl5ltd If you can get one for a good price, I have found the HP to be very good. I have an old video you may not have seen: th-cam.com/video/j4mLM1l5M7A/w-d-xo.html
lots of development man hours to pay for, but if you look inside you will find the answer. lots of expensive RF modules. Just a good mixer will cost hundreds of dollars. then there is the expensive box, display, graphics card, processing card.
Hi there, I wanted to ask if it’s okay with you if I show some of these videos as part of my own twitch stream. I‘m getting my first analyzer soon and I think it would make an interesting stream to show my „first steps“ on the device, using your videos as a guide. So it would be watching/reacting to a part of your video and then trying it out myself. Many greetings!
Being hopelessly OCD (look up anal retentive in the dictionary and you'll see my picture!) I always measure a device I'm about to test with a DMM to confirm there's no DC voltage present before hooking it up to my SA input.
People are not stupid. There is a reason for more expensive SA. I have several and can tell you each has its place. The TinySA is a great tool for some jobs.
Since this HP spectrum analyser shows signals that don’t exist for example at zero frequency, it cannot be trusted. I would never buy such an expensive and faulty piece of equipment. In fact, this item strikes me as a very poorly designed product.
I'm sorry you ended up feeling that way. All spectrum analyzers will have those signals at zero and negative frequencies, these are a result of using mixers. You will find some analyzers that hide these signals by limiting the left hand side of the display to a positive number. HP Tektronix Anritsu Rhode and Swartz will all have this behavior. If you use an external mixer to extend the frequency range of a analyzers then 100% of all analyzers will exhibit this behavior so it is important to know about it.
Thanks! Great for people who just want to grasp basic differences between an oscilloscope and a frequency analyzer!
Glad it was helpful!
Thank you for this series. Nobody at work has a complete idea how to use these or when to trust them but they are more useful and trustworthy than the software data collection system which is always troublesome while these guys just work if you know how to operate them.
This is what I'm waiting for.A lot of things about RF i learned from your videos.Thank a lot Sir.
The zero beat (0Hz tone) not only is not weird or fictitious but its existence is essential and the first clue that your SA is healthy (if you are looking at buying a used SA, not having a 0Hz tone is the first clue that the unit is defective). This is the leakage of the first LO at 2.1214GHz (in your particular SA, 8591E) through the first converter that passes through the second converter and appears as 0Hz after it is down-converted in two stages. That's why it is called LO feed-through. If you dont see it, the instrument's LO is defective. It exists in ALL swept frequency spectrum analyzers of any brand and any model, old or new.
I've always seen one. nice clue about a heathy one having it. any idea what the third conversion (down to 8khz for 30hz rbw) filter design looks like. can't find any schematics for that card. is it discrete or dsp?
Great introductory video. Looking forward to future videos on this subject.
you read my mind, i didnt want to ask u to do a stint on this, many thanx,
I have the same SA and I picked some tips from this video. Thanks for your nuggets of wisdom!
Thanks for doing this video. I have the exact same SA but mine has the tracking gen also. As per your earlier video I was cued to check my internal lithium backup battery. Mine was original from January 1995 (date was written on the battery) and it still measured good! I changed it anyway and I did not loose the calibration values (the supercap did its job). I have not explored all the fine details on this SA so hope you will get into some of those in future videos.
...you're lucky- I have an HP 3585A spectrum analyzer that I use for fixing transistor radios.
Nicely done and a timely series now with more affordable spectrum analyzer options easily accessible.
"Spectrum analyzers are strange." LOL! Yep, cool and strange at the same time. It's great that you call out these oddities.
I have a 8591EM without the built-in tracking generator, I also have a HP8444A w/o opt 059. ?? Is there a way to use tracking in another way that you know of. You are my HP vintage equipment go to. Before the 8444A your guidance was to use the generator from my Tiny SA and now I want to try this.
I Habs tried sweeping a 6m low pass filter with my 8601A which worked pretty good. BTW all of my HP equipment that I have purchased was because of your videos, Thank you. (I'm a 76 year old experimenter and licensed ham that should have started 50+ years ago. Thank you for all you have taught me)
if your analyzer has an IF output, then you can do this trick: th-cam.com/video/wKPkvuWWFXY/w-d-xo.htmlsi=Ps5YfzumBnXPMlnk
Excellent! This video is just what I was looking for as a newbie. Thnak-you!
The data spectrum analyzers display would great for pdn analysis. But I'm not sure how (if) I would want to connect the input of a sa to a high current power plane. (Up to 400 amps in the specific case I'm working on)
use non-contact probes: th-cam.com/video/RH9zHsdk5iE/w-d-xo.htmlsi=jXDIYL2FXnHqalZQ
Thanks IMSAI Guy! I just acquired an HP 8557A in a 182T display. Right off the bat the only thing I know that is wrong with it is that it has no sweep. I have never used a spectrum analyzer before. Is this video applicable to analog sweep SAs like the 8557A? For example, will an analog sweep SA also display negative Hz peaks?
search my channel for 8558. very similar to yours.
Thanks! I think I have a problem with the HP 182T display I need to figure out first...@@IMSAIGuy
Extremely helpful. Please keep up the good work.
I'm glad I saw this video. I just purchased the sencore SG 80. I'm looking for something to measure the RF output. Does the spectrum measure microvolts? I know there are RF power meters but the spectrum can do much more. I was just curios about the micrvolts(uV)
After watching this video. I now have better understanding about spectrum analyzers.
Thank you for your time.
Yes, also anything that measures dBm can give you uV since the uV is across 50 ohms. watts = volts^2 / 50
Thank you very much for the Tutorial
Great Channel.
In the case of Looking at a 50 watt rf radio signal to see the harmonics, with the attenuated rf coming out of a bird sampler at -40 db, wouldn't any harmonics present also be attenuated -40 db? Possibly causing the harmonics to be lowered to the noise floor and be rendered not visible?
I don't know the design of the bird samplers. but samplers I have build myself are not flat with frequency as are attenuators. One would sweep the sampler and determine the frequency response.
I have the hp esa-1500A
Can you make rf spectrum analyser using crt tunner and Arduino so everyone can touch SA
get a tinysa: th-cam.com/video/n6WEM3--Npc/w-d-xo.html
Thanks bro that was really neat. So what’s a good price for that particular model? What if I were to be able to find one from a guy that is retiring or that’s gonna give me a pretty good deal on it versus what’s the every day price?
depends on the options but, $700 typical, $400 good deal, I got mine for $250
@@IMSAIGuy wow I think I’ll take yours for 200, Alex (Alex Trebek).
If one were an ignoramus and wanted to purchase new; cheapest decent comparable model that’s not a piece of garbage? Hopefully under 1k
Siglent, about $1k
@@IMSAIGuy which model?
@@m.m.m.c.a.k.e the Siglent Technologies SSA3021X-TG is $1100 on Amazon
this particular SA already has a blocking capacitor at the input (47nF or 100nF, cannot remember exactly) it is rated at 25V but can handle more than that...so it's not that scary if you have some DC as long as it is not like 400V!
wow! you are right. I didn't notice that as it is hidden in the front attenuator. 47nf. thanks! no diode limiter like the 8558 has though.
oh, and it gets cal-ed out too. nice...
...is there a newer spectrum analyzer that has a comparable range to the HP 3585A?
www.keysight.com/us/en/products/spectrum-analyzers-signal-analyzers/x-series-signal-analyzers.html
So the 8591e says 9KHz upwards but shows 0Hz. Does it actually go down to 0? Can you actually view, say, a 1KHz signal?
No
Superb video, many thanks - also for all other brilliant vids on your channel👍🏻This fundamentals helps me now better to understand my FFT function on my scope, even when it's might not really comparable with the performance of an analyzer (especially by using a R***l 1074Z 😉)
P.S.: Like the manner of your vids and i'll certainly stay tuned - very educationally 🎯🏆👏🏻
The terminology is "Y as a function of X" or "Y vs. X" as dictated by mathematical standards.
You had it backwards. Below is correct.
Oscilloscope: Amplitude as a fn. of time, or "Amplitude vs. Time"
Spectrum Analyzer: Amplitude as a fn. of frequency, or "Amplitude vs. frequency"
I suggest you look at the simple explanations first. The word "versus" can mean "compared with". The spectrum analyzer does not graph a mathematical function. it plots two data points. so frequency compared to amplitude or amplitude compared to frequency are equivalent. A graph of the days temperature would be described as the hour vs temperature or the thermometer reading vs the time of day. I don't think anyone would say the temperature as a function of the time. I try to teach things in simple terms to reach a broad audience. (2,3) (4,5) (1,5) plotted could be x vs y or y vs x, it doesn't matter, or use term plotted 'against'
The first thing to find out is the price. Is it affordable or is it a rip off? With excellent oscilloscopes selling for lesss than $400, an excellent spectrum analyzer should also be in that price range.
I wish spectrum analyzers were at $400 but they seem be >$1000. Supply and demand I guess. There are some really nice units by Siglent. I love the used market and picked up this SA for $250.
Peak search, next left or right 👍
Hello there, could you please show us what kind of blocking capacitor you do use on your spectrum analyzer?
I have an old outdated one from HP but several companies make them:
www.pasternack.com/50-ohm-n-inner-dc-block-0.1-18-ghz-pe8213-p.aspx
How can I get a copy of the data for the memory if the master doesn't exist, can it be downloaded, thank you
sorry I do not understand the question
thanks so much for making this vid
What is diffrence between analyzer and acoustic
Not exactly sure about your question, but here is what I think you are asking. Acoustic is in the frequency range of 10 Hz - 20,000 Hz. There are spectrum analyzers that can operate at those frequencies. Most RF analyzers have a minimum frequency of 10,000 or 100,000 Hz.
@@IMSAIGuy no no i want ask what is spectrum analyzer machine and what we measure.and electroacoustic machine what measure can both machine is same
@@Reeshichohan Spectrum analyzer gives a graph of frequency (x) vs. power (y). am not familiar with what you call an electroacoustics machine.
@@IMSAIGuy sr can u plz give me a video or link how can connect measuring device to analyzer?
@@Reeshichohan th-cam.com/video/q66YkSwyh9w/w-d-xo.html
...no tracking generator?!
not that model. it did have the option
Awesome! Thanks!
If I was on 146.520 and connected my spectrum analyzer what's the best or near best setting to see fm modulation
here is a video showing how to measure various modulations: th-cam.com/video/q66YkSwyh9w/w-d-xo.html
What you see will be a function of the resolution bandwidth your spectrum analyzer is capable of. In that video, my analyzer was set to a RB of 300Hz.
Well done!
Thank you a lot sir!
How capable is the HP8921a SA functions compared to a dedicated unit like the 8591e ? Great channel, clear explanations, well presented. Vk5LTD
the 8921 spectrum analyzer is very basic. the 8591 is way better in specs and usability. however, the 8921 has a tracking generator that makes it much better than the 8591 in in certain tasks. the 8591 did have an option for a tracking generator.
@@IMSAIGuy My needs are relatively basic- ham radio tx tinkering. I'm looking to purchase an 8921a and know you have this instrument so would have a good grasp of the two units capabilities. I'm coming on board as a patron for all the content you do.
@@cl5ltd What you might be looking for is a radio service monitor or communications service monitor. The HP8920 and 8921 or IFR1500 IFR1200 or Marconi there are German ones too. They are multipurpose. But you can do a lot with a simple generator and RF voltmeter.
@@IMSAIGuy Yes, a comms test set is what i'm moving towards and know of a 8921a, IFR1200S & Marconi 2955 for sale at present- all about same price, all in Queensland. The HP seems to be more modern even if from much the same era and is well built gear.
@@cl5ltd If you can get one for a good price, I have found the HP to be very good. I have an old video you may not have seen:
th-cam.com/video/j4mLM1l5M7A/w-d-xo.html
that analyzer is an oldy but goody!
It was the gold standard 30 years ago
Major questions is: why do they cost so much, excluding tinySA, they start from thousand dollars.
lots of development man hours to pay for, but if you look inside you will find the answer. lots of expensive RF modules. Just a good mixer will cost hundreds of dollars. then there is the expensive box, display, graphics card, processing card.
Hi there, I wanted to ask if it’s okay with you if I show some of these videos as part of my own twitch stream. I‘m getting my first analyzer soon and I think it would make an interesting stream to show my „first steps“ on the device, using your videos as a guide. So it would be watching/reacting to a part of your video and then trying it out myself. Many greetings!
Go ahead!
Thank you
Being hopelessly OCD (look up anal retentive in the dictionary and you'll see my picture!) I always measure a device I'm about to test with a DMM to confirm there's no DC voltage present before hooking it up to my SA input.
I took my own advice and have a DC block on my SA at all times now.
Hp really does make anything doesnt it
you are nice
Way, way, way to expensive !!! Only stupid people will pay that much. Buy the tiny SA for $80.
People are not stupid. There is a reason for more expensive SA. I have several and can tell you each has its place. The TinySA is a great tool for some jobs.
Since this HP spectrum analyser shows signals that don’t exist for example at zero frequency, it cannot be trusted. I would never buy such an expensive and faulty piece of equipment. In fact, this item strikes me as a very poorly designed product.
I'm sorry you ended up feeling that way. All spectrum analyzers will have those signals at zero and negative frequencies, these are a result of using mixers. You will find some analyzers that hide these signals by limiting the left hand side of the display to a positive number. HP Tektronix Anritsu Rhode and Swartz will all have this behavior. If you use an external mixer to extend the frequency range of a analyzers then 100% of all analyzers will exhibit this behavior so it is important to know about it.
@@IMSAIGuy This...this kind of " basic" instruction is EXACTLYVwhy kids dont go into stem.
Good learning session. Thanks.