Understanding SSB

[CampDavid]

I bought an older Icom M700, I know nothing about SSB,

I was once told that here were no stupid questions, so here I go.

I am reading about cruisers nets and common marine ssb frequencies. I see USB and LSB often noted.

I assume USB is upper side band and LSB is lower side.

Does that mean on any given frequency you can select the upper side or the lower side, Thus two channels ( so to speak) witin one frequency? How would one do that?

I originally thought upper was the higher frequency's and lower were those below a given range.

On my radio there is a selector switch A3J A3A and A3H which are referred to as Emission modes, what do this switch do, what are the three modes used for?

If there were ten or so frequencies to program in for marine use, what would they be?

Thanks for any help, I am sure for some out there these stupid questions, for me it might turn on the lights.

If you did not know what frecquency to use I am assuming one would be lost in the very tall weeds

Fletch

[rusky]

Hi,

Originally Posted by CampDavid

I bought an older Icom M700, I know nothing about SSB,

I was once told that here were no stupid questions, so here I go.

I am reading about cruisers nets and common marine ssb frequencies. I see USB and LSB often noted.

I assume USB is upper side band and LSB is lower side. Basically correct

Does that mean on any given frequency you can select the upper side or the lower side, Thus two channels ( so to speak) witin one frequency? How would one do that? Not really, same frequency, its the amplitude - AM is full wave eg on 2182

I originally thought upper was the higher frequency's and lower were those below a given range. see above, but google RMS, square waves and it should also talk about lsb/usb etc

On my radio there is a selector switch A3J A3A and A3H which are referred to as Emission modes, what do this switch do, what are the three modes used for?

If there were ten or so frequencies to program in for marine use, what would they be? apart from 2182, the other are pre-programmed, and I have forgotten - someone else will chime in.

Thanks for any help, I am sure for some out there these stupid questions, for me it might turn on the lights.

If you did not know what frecquency to use I am assuming one would be lost in the very tall weeds.

Fletch

Also look at plugging a mike jack into your laptop, download JV Comm and you now have a weather fax.

I used to talk to 'our net' every morning at 0700 and again at 1700 if on passage. It was my' security blanket' - a bit like signing in.

[goboatingnow]

Originally Posted by CampDavid

I bought an older Icom M700, I know nothing about SSB,

I was once told that here were no stupid questions, so here I go.

I am reading about cruisers nets and common marine ssb frequencies. I see USB and LSB often noted.

I assume USB is upper side band and LSB is lower side.

Does that mean on any given frequency you can select the upper side or the lower side, Thus two channels ( so to speak) witin one frequency? How would one do that?

I originally thought upper was the higher frequency's and lower were those below a given range.

On my radio there is a selector switch A3J A3A and A3H which are referred to as Emission modes, what do this switch do, what are the three modes used for?

If there were ten or so frequencies to program in for marine use, what would they be?

Thanks for any help, I am sure for some out there these stupid questions, for me it might turn on the lights.

If you did not know what frecquency to use I am assuming one would be lost in the very tall weeds

Fletch

Upper and lower side bands are a band of frequencies with appreciable energy as a result of the AM process. In ssb the carrier is suppressed and one or the other sidebars is used. See http://en.wikipedia.org/wiki/Sideband. It's not two channels within one frequency, sideband are a group of frequencies immediately above and below the carrier

Emission modes are standardised descriptions of radio transmission methods http://en.wikipedia.org/wiki/Types_of_radio_emissions

A3e is normal broadcast long or medium am.

Google is your friend for this type of stuff

[Paul Elliott]

USB and LSB, as Goboatingnow explained, are a function of the SSB modulation. "SSB" stands for "Single Sideband". A regular AM radio station broadcasts a modulated carrier, and the resulting spectrum contains the carrier, and both sidebands. In SSB we discard the carrier and one of the sidebands, thus taking up much less space in the radio spectrum. This lets more people use the bands then would be the case with AM. SSB also gives you "more bang for the Watt", since you aren't wasting power transmitting the carrier and the extra sideband. This comes at the cost of radio complexity, but fortunately this is largely hidden from the operator.

What you *really* need to know about SSB, USB. LSB, is that in a particular band and service, all transmission is done with either USB or LSB. By convention, in the marine bands we use USB. In some ham bands we use USB, and in others we use LSB. There's seldom a good reason that one was chosen over the other, just that we might as well agree on one so we can communicate. Both the transmitter and receiver need to be set for a particular sideband.

[Auspicious]

Originally Posted by Paul Elliott

In some ham bands we use USB, and in others we use LSB. There's seldom a good reason that one was chosen over the other, just that we might as well agree on one so we can communicate.

In the case of the ham radio convention (40m and down are LSB, 20m and up are USB) back in the day when SSB was first becoming available the sideband filtering around the 10 MHz IF made it easier (and cheaper) to use LSB at lower frequencies and USB on higher frequencies. Ta da! A good reason. *grin*

[Paul Elliott]

Originally Posted by Auspicious

In the case of the ham radio convention (40m and down are LSB, 20m and up are USB) back in the day when SSB was first becoming available the sideband filtering around the 10 MHz IF made it easier (and cheaper) to use LSB at lower frequencies and USB on higher frequencies. Ta da! A good reason. *grin*

This makes sense, but in those prehistoric times weren't all the radios doing the sideband filtering at the second I.F. stage, which was usually 455 KHz? Of course I'm thinking about receivers, and perhaps the transmitters were the issue. I will need to dig up some old schematics or the ARRL handbook from that era.

To the original poster: Fortunately you don't need to know any of this technical trivia to operate your marine SSB!

[Auspicious]

Originally Posted by Paul Elliott

This makes sense, but in those prehistoric times weren't all the radios doing the sideband filtering at the second I.F. stage, which was usually 455 KHz? Of course I'm thinking about receivers, and perhaps the transmitters were the issue.

It was the transmitter side that drove the issues I think. I was a CW only guy back in those days so I just don't remember. All my SSB equipment have been appliances; I haven't built one.

[foggysail]

It is easier to understand what is meant by side bands if you have some understanding of an AM signal. Normal AM--- which stands for amplitude modulation requires a carrier frequency.

The carrier does just that, it carries the frequencies that ultimately one listens to. The carrier has no other purpose and it essentially is wasted energy after it serves it purpose of delivering intelligence that is in the modulation.

Before I go on, it has been years since I delved into this stuff, so someone might be able to correct any basic mistake. But I will go on as best I can remember.

Speech, music and for that matter all sound waves that we can hear are made of of low frequencies that are far too difficult to transmit. So instead, those low frequencies are used to modulate which means vary the amplitude of the carrier frequency at the audio frequency. The receiver's detector separates the audio from the carrier so that it can be listened to.

Now a funny thing happens on the way to the forum........... when frequencies are "mixed" such as a carrier and an audio frequency, the resulting mixture is 3 frequencies! The frequencies transmitted contain the carrier frequency plus AND minus the audio frequency.

For simplicity, assume a carrier frequency of 100Khz and a modulated frequency of 5Khz, the transmitted frequencies would be 100Khz, 105Khz and 95Kz. Now remember, the carrier is wasted energy!!! So in single sideband, the carrier frequency of 100Khz is filtered out BEFORE it gets transmitted!! So the two frequencies transmitted are the upper and lower sidebands of 95Khz and 105Khz.

Now as I mentioned, its been a long time for me on this stuff. Modern filtering techniques may be able to even filter out one of the sidebands to further save on transmitted energy...... such that either 105Khz OR 95Khz is transmitted. Not sure on that but others in our forum I am sure know more than me.

Hope this helps---

Foggy

[btrayfors]

Paul Elliott and Auspicious have it right; the other responses are partially correct only.

USB and LSB are not "a band of frequencies". They refer to the portion of the transmitted or received signal which contains the intelligence -- above or below the suppressed carrier frequency.

For example: let's take 14300 kHz USB (upper side band). The suppressed carrier frequency is 14300 all right, but practically no power is actually transmitted there. The intelligence (let's assume voice) is actually transmitted just above the carrier frequency, and occupies about 2.7kHz. In other words, it extends from 14300 kHz up to about 14302.7 kHz.

By convention, SSB frequencies are referred to by the carrier frequency, not the actual frequency portion where the voice is transmitted. There are exceptions to this when talking about data transmission; then, sometimes, the actual data frequency is used.

Similarly, for LSB the voice portion occupies the 2.7 kHz or so just below the carrier frequency. So, in a sense, you're correct: for each SSB frequency there are two "channels", USB and LSB. Once in a while hams make use of this, but almost always the conventions are used. Marine SSB is on USB ONLY. Ham SSB is mostly on USB except for 40 meters, 75 meters, and 160 meters where LSB is the convention.

Now, let's get specific. The Icom M700 generally has LSB capability, but it's not marked on the panel. It's the switch position just to the left (counterclockwise) of the A3J (USB) position.

A3J, A3A, and A3H refer to SSB modes. The only one you'll use is A3J. A3A and A3H are reduced carrier and full carrier sideband. While transmissions on 2182 in the past were mostly AM and sometimes full carrier (A3H) to provide a homing signal for radio direction finding, these days virtually all HF marine voice communication uses A3J (single sideband suppressed carrier).

RE: which frequencies to program into your radio, here's a schema I often use with the M700:



Hope this helps a bit,

Bill
WA6CCA

[goboatingnow]

Originally Posted by btrayfors

Paul Elliott and Auspicious have it right; the other responses are partially correct only.

USB and LSB are not "a band of frequencies". They refer to the portion of the transmitted or received signal which contains the intelligence -- above or below the suppressed carrier frequency.

For example: let's take 14300 kHz USB (upper side band). The suppressed carrier frequency is 14300 all right, but practically no power is actually transmitted there. The intelligence (let's assume voice) is actually transmitted just above the carrier frequency, and occupies about 2.7kHz. In other words, it extends from 14300 kHz up to about 14302.7 kHz......

Sorry to avoid using to many terms it is a band of frequencies , the bandwidth of the sideband is equal to the modulation signal bandwidth. That's a band of frequencies as in to make the distinction from a point frequency. ( yes it's not radio engineering language,but we're trying to keep it simple here)

Dave

[LoveMyWoodie]

Was always " afraid " of SSB because I didn't understand it and thought of an old man I knew who lived in a shack with an antennae that was bigger than his house.

So , this thread has got me back into looking at what may be the only type of communication "if" the Internet/cell goes down for "some" reason.

Is ham radio and SSB the same?

If I were to buy used SSB ,which one should I get and what should I look for and stay away from?

I assume we need a license to transmit but not to listen-for now?

Sounds like a new hobby-fun

Thanks

[btrayfors]

Dave,

Yeah, it's difficult to explain sometimes.

In radio parlance, a "band" generally refers to a wide range of frequencies allocated for a specific purpose, e.g., "the 20-meter amateur band" or "the 8 mHz marine band" or the "aircraft band", etc. These "bands" are fixed, i.e., have defined upper and lower frequency limits.

The term, "sideband" is a bit different and has a much more narrow definition, i.e., that portion of the modulated signal extending above and below the carrier frequency. In most types of modulation used in marine and amateur radio the sideband only extends a few kHz, while "bands" generally extend over several tens of kHz or, as in the amateur 10-meter band, several hundreds of kHz. Clearly, the sideband is tied to the carrier and moves when it moves....hopefully staying within the allocated "band" :-)

Bill

[btrayfors]

Originally Posted by LoveMyWoodie

Was always " afraid " of SSB because I didn't understand it and thought of an old man I knew who lived in a shack with an antennae that was bigger than his house.

So , this thread has got me back into looking at what may be the only type of communication "if" the Internet/cell goes down for "some" reason.

Is ham radio and SSB the same?

If I were to buy used SSB ,which one should I get and what should I look for and stay away from?

I assume we need a license to transmit but not to listen-for now?

Sounds like a new hobby-fun

Thanks

It's a wonderful hobby which can stick with you for life! There are more hams in the U.S. now than ever before....about 700.000 of them!

No, ham radio and SSB are not the same. Ham radio refers to the hobby or to a radio used in that hobby. SSB (single sideband) refers to the type of signal generated by that -- or other -- radios. Many radios use SSB emissions, not just ham radios or marine radios.

What to buy? The market is full of new and used radios. Depends a bit on what you want to do with it, and how much you want to spend. A good radio to get started with, new, is the Icom 718....just over $500. You can find functional used ham radios on eBay and elsewhere for much less.

Yes, you do need a license to transmit. But, you can listen on virtually any frequency.

There are good study guides available, classes available almost everywhere, no code requirement exists now in the U.S., and it's very inexpensive and easy to get your license.

Dive right in!

Bill

[LoveMyWoodie]

OK,thanks.

Good idea -diving right in !

What other things can you do with SSB?

I hear -Internet? weather fax?

anything else?

500 is cheap-my iPhone cost more than that and the usage is over a hundred a month.

Guess I would like to spend about a grand.all in.

Buy new or used?

What new coming down the pike in SSB in regards to features or portability?

Handheld ?

How hard is it to get a lic.? Online?

Cheers

[btrayfors]

Originally Posted by LoveMyWoodie

OK,thanks.

Good idea -diving right in !

What other things can you do with SSB?

I hear -Internet? weather fax?

You can do email if you add a modem; you can receive WX fax with any SSB receiver and appropriate software; you can do TV, FM, satellite communications, moon bounce, DX-ing, you name it. The hobby is very broad.

anything else?

500 is cheap-my iPhone cost more than that and the usage is over a hundred a month.

Guess I would like to spend about a grand.all in.

Buy new or used?

Depends. You can't go wrong with a good entry-level transceiver. You'll have to add antenna and misc. other things to get going.

What new coming down the pike in SSB in regards to features or portability?

Ham radios are available today in any size you like, from handhelds and ultra-portable full-featured tiny rigs like the Yaesu FT-817 to the large "boat anchor" rigs for your shack.

Handheld ?

While handheld HF transceivers are available, they're quite limited. Of much more use are the VHF 2-meter handhelds and the huge network of 2-meter repeaters throughout the country.

How hard is it to get a lic.? Online?

Not hard. Lots of study materials available, including some good online courses. The ARRL (arrl.org) has printed study materials and a wealth of information for hams at all levels. Your local radio clubs generally have classes and all testing is by volunteer ham examiners. Tests are held periodically and the fee is nominal or non-existent.

Cheers

Where are you located? What do you plan to do with ham radio? Home use? Use on a boat? Airplane? etc.

Bill