Single Side Band and Frequency

I asked this same question on my Facebook friends to strike a conversation. I have decided to ask amateur radio operators on RR here as well.

Kind of trying to figure out when listening on sideband, many people have different tones of voice. Some higher some lower in tone. Sideband seems to be a funny mode when it comes to pitch and radio frequency. We expect to be on say 14.255mhz usb. We see our radio is on frequency. Then we hear that sharp high pitch voice that can confuse us to think is my radio aligned right? Same thing with a voice with a lower pitch. I find myself trying to tune it in to their natural voice the best I can then to notice my radio is 50-200 hz off. Are we really able to go by radio frequency when listening in on sideband?

So many things can cause this. Normally it boils down to operator error on the part of the operator who is sounding off frequency.

Incorrect RIT????

jhooten said:

So many things can cause this. Normally it boils down to operator error on the part of the operator who is sounding off frequency.

Click to expand...

It kind of had me worried because on some stations I find myself correcting ppm error then the other station talks and the ppm error is wrong again.I usually just tune in hertz. Now You tell me its a common thing for some amateurs not setting RIT correctly?

Frequencies can drift if crystal temperature changes. SSB radios typically have a frequency adjustment (clarifier) to compensate for this, but not everyone adjusts this correctly.

SSB has a much lower "acceptable" margin of error than any other modulation method. A 500Hz error is only .00357% off at 14Mhz. It's not noticeable during AM or FM, but can make someone sound like either a chipmunk or Treebeard on SSB, depending on the direction of the error.

Happy Medium

I guess if anyone asks the same question the best answer would be "find a happy medium" We cant keep up with the variety of many many radios with different offsets and operator habits. I certainly cant come on frequency and demand the operator to fix his RIT which would be laughable.

screamin72 said:

I certainly cant come on frequency and demand the operator to fix his RIT which would be laughable.

Click to expand...

Indeed. That's the thing though, there's really no such thing as "off frequency." I've been known to purposefully choose a frequency like 14.202.500 just to see how many people say "You're off frequency from 14.200/14.205." So many people (new hams and old) get stuck on the VHF/UHF mentality that your frequency must end in a 5 or 0.

On SSB, if the station you're tuning in sounds "normal" on 14.202.200 then use that frequency. With the bands sometimes being so crowded, you have to stick a signal where there's room, and that's not always going to end with a 5 or 0

What a releif!

WB4CS said:

Indeed. That's the thing though, there's really no such thing as "off frequency." I've been known to purposefully choose a frequency like 14.202.500 just to see how many people say "You're off frequency from 14.200/14.205." So many people (new hams and old) get stuck on the VHF/UHF mentality that your frequency must end in a 5 or 0.

On SSB, if the station you're tuning in sounds "normal" on 14.202.200 then use that frequency. With the bands sometimes being so crowded, you have to stick a signal where there's room, and that's not always going to end with a 5 or 0

Click to expand...

I did notice some like 14.300 and a few nets choose a 5 or 0 frequency but most others are wherever the best pitch is at which would be the best natural sound we can tune in. This probably goes for the eSSB users (extended single side band) wider audio bandwidth compared to SSB.

BTW 15 meters is hopping right now.

I can just tune to a VOLMET or a WLO mobile radio to check ppm then if it sounds right I know I am good for now on.

Thanks everyone for the replies and anymore to come this helped me understand better..

SSB reception requires an added local oscillator in the receiver, commonly called a "B.F.O." for "beat frequency oscillator". In older radios the frequency of the BFO is controlled by a knob and it's hard to get the right frequency. As the BFO (whose job is to locally replace the carrier wave filtered out at the broadcast end) changes frequency the decoding of the SSB signal gets better or worse.

Many hams tend use older tube radios which have a bit of frequency drift, and if your radio (as most modern transistor radios do) dials in the "correct" frequency then the folks who are a little off frequency will sound odd.

Can your receiver tune finer than 1 Khz? If not you will hear a fair number of "odd" sounding SSB stations as a lot of hams tend to tune half a kiloherz above or below. For instance the Noontime Net in the pacific northwest uses 7258.5 KHZ. If your receiver can't tune this frequency you'll hear the sound as rather odd.

There may be a 'BFO" control on your receiver which you can adjust to hear better.

Ed_Seedhouse said:

SSB reception requires an added local oscillator in the receiver, commonly called a "B.F.O." for "beat frequency oscillator". In older radios the frequency of the BFO is controlled by a knob and it's hard to get the right frequency. As the BFO (whose job is to locally replace the carrier wave filtered out at the broadcast end) changes frequency the decoding of the SSB signal gets better or worse.

Many hams tend use older tube radios which have a bit of frequency drift, and if your radio (as most modern transistor radios do) dials in the "correct" frequency then the folks who are a little off frequency will sound odd.

Can your receiver tune finer than 1 Khz? If not you will hear a fair number of "odd" sounding SSB stations as a lot of hams tend to tune half a kiloherz above or below. For instance the Noontime Net in the pacific northwest uses 7258.5 KHZ. If your receiver can't tune this frequency you'll hear the sound as rather odd.

There may be a 'BFO" control on your receiver which you can adjust to hear better.

Click to expand...

It's software defined radio. It has all 12 digits of a frequency.

screamin72 said:

It's software defined radio. It has all 12 digits of a frequency.

Click to expand...

So pick the peak on your band scope, then adjust the frequency to where it sounds best. Not all receivers nor transmitters are the latest stuff. There are still tube units in use here in the southwest corner of Canada and they often drift a bit off their nominal frequency.

Most ham transceivers have a button labeled "RIT" which changes the receive frequency while keeping the transmitted frequency unchanged.

screamin72 said:

It's software defined radio. It has all 12 digits of a frequency.

Click to expand...

That doesn't mean all 12 digits are accurate.

Ed_Seedhouse said:

So pick the peak on your band scope, then adjust the frequency to where it sounds best. Not all receivers nor transmitters are the latest stuff. There are still tube units in use here in the southwest corner of Canada and they often drift a bit off their nominal frequency.

Most ham transceivers have a button labeled "RIT" which changes the receive frequency while keeping the transmitted frequency unchanged.

Click to expand...

Setting the happy medium' is what I came up with after all these replies. Not all radios are tuned the same as the next. Some off some on frequency.

zz0468 said:

That doesn't mean all 12 digits are accurate.

Click to expand...

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well. Many many SDR software has virtually the same meaning in frequency. besides I am not discussing 12 digits of frequency. The topic is SIngle Side Band and Frequency. ED_Seedhouse asked the question to me so the he can know what I am using so he can understand and make a good reply. This is not a debate on digits of a frequency.

And this goes right back to ZZs statement "that doesn't mean all 12 digits are accurate" meaning your receiver could be slightly off frequency and especially if your using a TV dongle SDR with a converter. Your SDR# might display 20+ digits on screen but if the master oscillator is off frequency (and all dongles are off a bit), then all those digits don't add up to the right frequency.

Dongles also drift as they warm up for an hour or so and its usually not a problem for AM or FM reception but you will notice things can be off frequency when listening to SSB or CW signals. You cal calibrate your receiver to WWV or some other known standard but you may have to do this often with a dongle and SDR#.

And as others have mentioned there are a host of various radios on the air, some locked to rubidium standards or GPS and some with free running VFOs and no good means to tell where they are transmitting. That's why its called amateur radio.
prcguy

screamin72 said:

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well. Many many SDR software has virtually the same meaning in frequency. besides I am not discussing 12 digits of frequency. The topic is SIngle Side Band and Frequency. ED_Seedhouse asked the question to me so the he can know what I am using so he can understand and make a good reply. This is not a debate on digits of a frequency.

Click to expand...

screamin72 said:

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well.

Click to expand...

Again, you can display the frequency to 100 decimal places, and that doesn't make the actual frequency any more accurate. If the reference oscillator in the dongle is off by a few hundredths of a percent, only the first 6 digits or so of the display are actually meaningful. Anything further to the right is basically random crap.

screamin72 said:

It kind of had me worried because on some stations I find myself correcting ppm error then the other station talks and the ppm error is wrong again.I usually just tune in hertz. Now You tell me its a common thing for some amateurs not setting RIT correctly?

Click to expand...

I was talking to a fellow extra, who has been one long enough to have been required to pass a 20 wpm code test, not too long ago. He is consistently 500 hz high. So I ask him if he had forgotten to turn the RIT off at some point. "What's a writ?"

jonwienke said:

Again, you can display the frequency to 100 decimal places, and that doesn't make the actual frequency any more accurate. If the reference oscillator in the dongle is off by a few hundredths of a percent, only the first 6 digits or so of the display are actually meaningful. Anything further to the right is basically random crap.

Click to expand...

Again,

IN UNDERLINE AND RED

Because some wont listen

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well. Many many SDR software has virtually the same meaning in frequency. besides I am not discussing 12 digits of frequency. The topic is SIngle Side Band and Frequency. ED_Seedhouse asked the question to me so the he can know what I am using so he can understand and make a good reply. This is not a debate on digits of a frequency.


Now once my RTL warms up it is fine and on frequency. My USB dongle is fine you are powerless to convince me that it is off. these amateurs already done replied that there are many variables and the main one being operator error. this is not to say all amateurs are in error It is only when the error happens.

It was already noted that There are many vintage transmitters with a lot of drift on the air.

I sit here daily and make the corrections when I move up or down far enough in frequency. My topic was to see if I was correct in making a happy medium tuning in ssb transmissions because it was admitted there is no 'on frequency' for ssb by a radio amateur. There is no 5 or 0.

I am proficient in haggling HDSDR and the RTL using the calibration technique using ECSS and the LO frequency calibration tool when you right click on the EXTIO button. that gets your correction down to the hundredths. this works well for ssb just make the additional ppm correction after setting it to the up-convert shift of 125000000hz AFTER using the LO Frequency calibration tool. SDR# is unable to perform this.

For you to reply about the rtl dongle is a whole different subject and in the wrong thread. This was not discussing the rtl dongle. Once again I wanted to see if I was right in making a happy medium tuning in ssb stations. This implies I want it as close as possible.

Its all relevant to the thread, you asked a question and several of us gave various reasons for voices sounding different on SSB, most of which is due to the transmitter or receiver being off frequency. Thanks for clearing up the receiving side and as a receive only user you just have to tune people in to make it sound best to you and that could leave you with some unusual tuning steps.
prcguy

screamin72 said:

Again,

IN UNDERLINE AND RED

Because some wont listen

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well. Many many SDR software has virtually the same meaning in frequency. besides I am not discussing 12 digits of frequency. The topic is SIngle Side Band and Frequency. ED_Seedhouse asked the question to me so the he can know what I am using so he can understand and make a good reply. This is not a debate on digits of a frequency.


Now once my RTL warms up it is fine and on frequency. My USB dongle is fine you are powerless to convince me that it is off. these amateurs already done replied that there are many variables and the main one being operator error. this is not to say all amateurs are in error It is only when the error happens.

It was already noted that There are many vintage transmitters with a lot of drift on the air.

I sit here daily and make the corrections when I move up or down far enough in frequency. My topic was to see if I was correct in making a happy medium tuning in ssb transmissions because it was admitted there is no 'on frequency' for ssb by a radio amateur. There is no 5 or 0.

I am proficient in haggling HDSDR and the RTL using the calibration technique using ECSS and the LO frequency calibration tool when you right click on the EXTIO button. that gets your correction down to the hundredths. this works well for ssb just make the additional ppm correction after setting it to the up-convert shift of 125000000hz AFTER using the LO Frequency calibration tool. SDR# is unable to perform this.

For you to reply about the rtl dongle is a whole different subject and in the wrong thread. This was not discussing the rtl dongle. Once again I wanted to see if I was right in making a happy medium tuning in ssb stations. This implies I want it as close as possible.

Click to expand...

prcguy said:

Its all relevant to the thread, you asked a question and several of us gave various reasons for voices sounding different on SSB, most of which is due to the transmitter or receiver being off frequency. Thanks for clearing up the receiving side and as a receive only user you just have to tune people in to make it sound best to you and that could leave you with some unusual tuning steps.
prcguy

Click to expand...

Some people dont really like RTL so I had to speak up because I understand the nature of the dongle. I do not need it repeated to me. Been using 3 of them since March. It's a routine for me. Correcting ppm offset is not even remotely an issue to me. ALL I wanted to know was hey we need to tune it to a happy medium after calibrating it to the best of our ability for SSB reception and ALL digits are VERY useful. You didn't say it but one thought the last 3 was 'crap'. NOT true. I find no evidence that the last 3 digits useless because of the dongle's drift. This thread was not meant to be about ppm correction and the rtl dongle.

Its also can be read as 'Is my radio close enough in frequency to your transmitted signal?' Happy medium because I would never be able to verify until the operator mentions the frequency tuned on. If I see HDSDR is off then the ppm correction gets fixed. Usually I can get it right tuned on the maritime mobile net on 20 meters. I forget the frequency it is a good reference. Also with other nets.

screamin72 said:

Again,

IN UNDERLINE AND RED

Because some wont listen

Click to expand...

Well, then, calm down and LISTEN. :evil:

Everything in my post below is germane to your original question. Learn something.

screamin72 said:

SDR# has 12 digits. HDSDR has 10 digits they all mean the same. cuSDR and powerSDR has 10 digits as well. Many many SDR software has virtually the same meaning in frequency.

Click to expand...

No.

You're mistaking accuracy with resolution. They are not the same thing. Unless your receiver is GPS/Cesium locked, I will guaran-damn-tee you that it's not "accurate". Even rubidium will be off slightly, as it's only a secondary standard.

Depending on the accuracy of the time base in your receiver, it could be bad enough that ALL the digits are wrong (unlikely). A more likely scenario is that all the digits beyond 3 or 4 to the right of the decimal place are wrong, and therefore useless.

I think it's safe to assume that you're not locked to a good reference source, therefore, your 12 digit display IS WRONG. PERIOD. END OF ARGUMENT.

And so is everyone else.

A station on the maritime mobile net is NOT to be considered a "good" reference.

So, with everyone being off frequency slightly (or more than slightly), it stands to reason that when everyone says they're listening or transmitting on 14.255, there will be some error in frequency between every transmitter, and every receiver. How much error depends on the accuracy of the station's frequency reference. Some can actually be pretty close, others will be high or low by some random amount. The end result is, you will hear the frequency error in the demodulated SSB.

The human ear/brain combination will detect a frequency error in demodulated SSB within a couple of cycles. When it starts to be a 20 or 30 Hz error between the transmitting station and the receiver, then the "donald duck" sound starts to become quite noticeable.

screamin72 said:

Now once my RTL warms up it is fine and on frequency. My USB dongle is fine you are powerless to convince me that it is off.

Click to expand...

Translation: we are powerless to pull your head out of your ***, and make you understand the laws of physics that guide the principles of electronics and radio.

:roll:

screamin72 said:

...these amateurs already done replied that there are many variables and the main one being operator error. this is not to say all amateurs are in error It is only when the error happens.

Click to expand...

The biggest operator error hams make, in terms of frequency determination, is making the assumption that THEY ARE RIGHT.

screamin72 said:

I sit here daily and make the corrections when I move up or down far enough in frequency. My topic was to see if I was correct in making a happy medium tuning in ssb transmissions because it was admitted there is no 'on frequency' for ssb by a radio amateur. There is no 5 or 0.

Click to expand...

The determination of a given frequency being a multiple of 5 KHz or not is purely operator preference. Some people are neurotic that way. In other cases, it's by rule, and you MUST abide by that, within a certain tolerance. In the 60 meter band, and the SSB channels, for example, the frequency given is intended to be quite precise. In the "normal" amateur bands, "correct" is merely staying within the band and sub-band edges. Anything else goes.

So, the real answer boils down to three things:

1. Stay legal, and within the band edge. Nothing else really matters.

2. Tune received SSB signals to your preference. If you want zero error, learn to use RIT, and set YOUR receiver to where it sounds good.

3. Your USB dongle frequency readout is probably useless beyond 1 KHz resolution. Really. Want to find out for sure? Tune in WWV on 2.5, 5, 10, or 15 MHz and see what the beat note is. THEY (WWV) are "accurate". Everyone else just thinks they are. And even WWV and NIST will state what THEIR margin of error is. I think their hydrogen fountain frequency standard is accurate to within a few parts in 10e-15.

BTW, I know from what I talk about... My home lab and parts of my ham station is referenced to a frequency standard that is measured accurate to within 1 part in 10e-13.

If you'd like to learn more, ask me. I'll steer you in the right direction.