Understanding Single Sideband
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- เผยแพร่เมื่อ 16 ก.ค. 2024
- This video explains the fundamental concepts behind single sideband (SSB) modulation and the most common variants of single sideband signals.
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I have to say, these tutorials from Rhode and Schwarz are a work of art. Anyone who is teaching electronics will appreciate how good they are. My hats off to the person/people making these videos! Thank you so much
Awesome explanations! Now I see why the upper sidebar is used!! Thank you!
Glad it was helpful!
I've been searching for a good explanation of USB and LSB for a while. This clarifies a lot!
Glad it helped!
As a new ham - thanks for posting this!
My pleasure! 73 DE KO4LZ
Best explanation I've found so far. So here is a comment to boost engagement :)
Always appreciate comments - thanks!
Great explanation. Couldn’t have been cheap to get Brent Spiner to narrate.
Lol - I think he's probably making enough money off "Picard" :) But you may notice that I use contractions and Data doesn't.
Been a Ham radio operator for over 50 years....excellent sxplaination.
Thanks!
First time I’ve been able to understand ssb being explained. Thanks 🙏
Thanks for the feedback!
Nice explanation! Simple and to the point.
very good explanation, thanks for sharing
An explanation about SSB second to none! I can understand that many find SSB hard to grasp. It's not a piece of cake to understand. Might this help? Let's go back to the old CW method. Say, a one Mhz signal is sent from person A. A person B sets his/her BFO (beat freq. osc.) to 1kz over or under one Mhz. He or she will hear a 1kz tone. Imagine that the sender varies the 1Mz by wiggling the knob, or whatever, to vary the 1Mz by a little. The receiver would hear what would sound like a person singing at 1Hz with vibrato----perhaps Pavarotti is singing.
Well, this is hardly SSB but it's a way to start understanding it. If you have a receiver with a BFO, you can tune to SSB signals make them out.
I sincerly hope that Rhode and Swartz don't mind my comment. Again, their presentation was par excellence.
It's a great comment and a fascinating explanation - thanks for sharing!
Really informative! Thank you...
Thank you!
The best explanation of SSB I have run across yet! But, without ANY carrier Tx what info is them Tx to 'inform' the Rx on the specs of re-insertion? This would round the explanation out to completion.
Unless the Tx frequency is already known, the correct Rx frequency is often determined simply by tuning and listening to when the received audio (assuming human speech) sounds "normal" Being slightly off-frequency results in what many people call the "Donald Duck" effect.
Excellent, concise. Thank you.
Thank you!
Very useful. Thanks a lot.
This is a good explanation. Thank you.
Thanks for the feedback!
Thank you very much.
Wanna be Ham here. Thanks for this!
thank you so much
Excellent
thank you
I'm sure this is a really good explanation, I'm just not smart enough to understand any of it.
Same
When you take a frequency (any), and mix (add) it with another frequency, the difference AND the total of these two will also appear.
Example: when you strike the 880 Hz of a tuning fork, and at the same time a (dé-tuned) 878 Hz of an instrument, you will hear the difference (2Hz), AND the total (1758 Hz, often less noticeable).
By the same principle two extra energy bands form when you take a carrier, and ADD a modulation on it. The difference with the example is that these were low frequencies, and the difference was small (2 Hz), while the addition was large (1758 Hz) compared with the ground frequency of 880 Hz. But if you use an example of 10 MHz with a modulation of 1KHz, the difference is 9.999.000 Hz and the addition is 10.001.000 Hz. Two extra frequencies are formed, the side bands.
When you would not use 1000 Hz modulation, but spoken sound, a whole spectrum is formed as side bands.
(Don't ask me to much, I am just finding out myself 😏 )
@@erikdenhouter i understood a little much by your explanation, actually I like to learn things with explanations like this (*by practical examples)
@@OmkarOP_07 Thanks. You could make your own example by using pen and paper. Plot two slightly different frequencies sine waves under or over each other (at least 10 waves wide), and start adding the points from both on the y-ax. So add the hight from the y-ax from the first by the hight of the second, and plot that value as a new (3th) signal. When you add enough points you will see the difference between the two also appear on that new wave. That's how I learned it on school in the '70, drawing by hand and the experience to see it appear. Only then I did not know that it is the base of RF side bands.
@@erikdenhouterI don’t know what band, modulation or spectrum means for example. I was shopping for a new radio with shortwave and it said it has SSB so I wanted to research what it was. Thanks. I actually installed antennas and did the installation and maintenance of high tech gadgets at work. I was always reading up on things before I worked on them or installed them for the power company. It was fun.
Thank you for your helpful video - appreciated. When transmitting a 1kHz tone through the mic on an SSB radio on USB or LSB, say, 28.000000Hz (28MHz) my transceiver's frequency counter indicates 28.000000Hz. However, feeding the transceiver output into a frequency counter, I see 28.001020Hz on USB and 28.998330Hz on LSB. Ignoring the fact my transceiver may need a tune-up, ideally should I see exactly 1kHz above and below the target frequency (28MHz) for USB and LSB respectively? I found that adjusting the tone affects the frequency displayed on the frequency counter's indication of the radio's transmit frequency. Aside from setting the offset frequency of a given SSB radio to what its service manual advises, which may not be correct as a radio ages, especially on older radios, is 1kHz transmitted through the mic into a frequency counter an accurate enough way of adjusting the offset trimmer to obtain the correct output frequency on an SSB radio?
Thanks 🙏
Would the method of producing a single sideband signal be the same as standard AM modulation followed by signal processing to remove the carrier and other sideband (some sort of filter)?
It’s an excellent explanation but it’s still a very heady concept to understand. I wonder if people who get it have patience for those who don’t grasp the idea.
Part of the reason I make these videos is that it often takes time for me to get things that other people seem to understand right away :)
Thanks 💜🇨🇦
excellent
Ok
After 2:22, what you said, it means we don't transmit carrier wave alongside with modulating signal? Nice video btw
Why is the graph not rotated 90 degress to resemble an oscilliscope trace? I've see it like this before and it's confusing to not see the time domain horizontal.
But how do you transmit anything without the carrier? Aren't the sidebands an effect of the carrier?
Can I have some time domain waveforms please
Hello! It`s a ood video! Have you any video about the syntetic SSB forming method?
Thanks. Sorry, but I'm not quite sure what you mean by the synthetic method. There are a number of ways of creating a SSB signal, e.g. filtering, phasing (mathematically, the Hilbert transform), etc. One could also create (synthesize?) a SSB signal directly as IQ data, but this is considerably more complex.
@@pauldenisowski I mean this quite old publication : .
3. Hawker P. Polar loop SSB transmitter". Radio Communication; 1979. Sept.. p. 828 - 829. Firstly they forming SSB on quite small frequency, secondly they detecting this SSB signal by frequency and analog detectors. Finally they modulating a carrier RF frequency by phase and DSB modulators simultaneously. I understand so.
@@andrewandrosow4797 Thanks for the pointer! Interestingly, when I search for "synthetic SSB" (in English) I don't find anything, but I did find a number of very interesting articles (в русским языке) when I searched for "синтетический SSB" For example: "Новый способ формирования SSB сигнала, В. Поляков (RA3AAE), Радио 4-84". Уча других, также учишься ...
I have a question : I understand the presence of the carrier frequency but what I don't get is why does the signal "bleeds" to frequencies before and after ?
After all, the modulated signal is at the carrier frequency right ?
I don't understand this as well, i suppose this has to do with more complicated math :(
When you take a frequency (any), and mix (add) it with another frequency, the difference AND the total of these two will also appear.
Example: when you strike the 880 Hz of a tuning fork, and at the same time a (dé-tuned) 878 Hz of an instrument, you will hear the difference (2Hz), AND the total (1758 Hz, often less noticeable).
By the same principle two extra energy bands form when you take a carrier, and ADD a modulation on it. The difference with the example is that these were low frequencies, and the difference was small (2 Hz), while the addition was large (1758 Hz) compared with the ground frequency of 880 Hz. But if you use an example of 10 MHz with a modulation of 1KHz, the difference is 9.999.000 Hz and the addition is 10.001.000 Hz. Two extra frequencies are formed, the side bands.
When you would not use 1000 Hz modulation, but spoken sound, a whole spectrum is formed as side bands.
(Don't ask me to much, I am just finding out myself 😏 )
i want your presentation file
does SSB reach 80 miles?
Why do we again have to insert the carrier wave at the receiving end to demodulate the modulated signal ??
and how both the upper and lower sidebands are carrying the same information ??
When a mixer combines two signals -- in this case, the carrier and the modulating signal (usually human voice) -- it produces products at both the sum and the difference frequencies. If the input were a pure 1000 Hz audio tone, you would see two products appear in spectrum, one of them below the carrier and one of them above the carrier, both 1000 Hz from the carrier (see slide 3). So we have two copies of the modulating signal, one in each sideband , both of which contain the same information, and this is true whether the modulating signal is pure tone or human voice with a wide range of spectral components.
With regards to carrier reinsertion: if we want to reverse this process and "de-modulate" the signal, we need to mix the sideband with a carrier, so to speak, to recover the modulating signal. Since SSB doesn't transmit a carrier, we need to "re-insert" one. If we reinsert the carrier at the exact frequency of the original (but not transmitted) carrier, the recovered audio will sound like the original audio. If the reinserted carrier is slightly too high or too low (not an uncommon situation), the frequency of the demodulated audio will be changed. I've heard SSB called "silly sideband" because a slightly-off re-inserted carrier can make the audio sound like Donald Duck : )
Hope that helps!
@@pauldenisowski nice explanation but why does reinsertion of the carrier wave make a difference in recovering the original audio signal?
@@AS-nx9fu The receiver demodulates by again mixing the received signal with the carrier frequency. Hence you need this carrier. (or more generally speaking: you need to know this carrier frequency and phase)
I STILL dont get it how you can have a sideband without the carrier. If the sideband is created by modulating the carrier energy, but you take that carrier energy, how can you modulate that which isnt there?? Its like saying 'here is a sandwich' while suppressing the bread. A sandwich MUST have bread or its not a sandwich.
Hi there again, I get the math side of it, but in the world of physics why are these side bands created?
guys in what frequency range is SSB normally used?
SSB is used primarily for HF (< 30 MHz). The big advantage of SSB is that it's spectrally efficient compared to double-sideband AM or FM, and the limited spectrum available at HF makes this efficiency important. You'll sometimes see SSB being used up to VHF, but the vast majority of SSB is found at HF frequencies.
I appreciate your effort to explain this but I'm unclear why a range of frequencies is used on AM when the carrier is unchanging unlike FM.
When you take a frequency (any), and mix (add) it with another frequency, the difference AND the total of these two will also appear.
Example: when you strike the 880 Hz of a tuning fork, and at the same time a (dé-tuned) 878 Hz of an instrument, you will hear the difference (2Hz), AND the total (1758 Hz, often less noticeable).
By the same principle two extra energy bands form when you take a carrier, and ADD a modulation on it. The difference with the example is that these were low frequencies, and the difference was small (2 Hz), while the addition was large (1758 Hz) compared with the ground frequency of 880 Hz. But if you use an example of 10 MHz with a modulation of 1KHz, the difference is 9.999.000 Hz and the addition is 10.001.000 Hz. Two extra frequencies are formed, the side bands.
When you would not use 1000 Hz modulation, but spoken sound, a whole spectrum is formed as side bands.
(Don't ask me to much, I am just finding out myself 😏 )
@@erikdenhouter Thank you for your help.
What's the opposite of understanding for dummies?
Not bad, but too simplistic. What is combining signals? It is multiplication of signals that can explain why the sidebands are formed. Add a little math for the more inclined that want to understand more than the magic.
Nope, still lost
Almost made it to the two minute mark and said "fuck this shit.....back to porn"
I was just trying to make music 😅 i think this is a little over my head