Why are SSBs so susceptible to noise?

[S/V Illusion]

Originally Posted by trifan

All of y'all missed the point with all the technical answers. The answer is "money" and is tied to one of the comments about being "old" tech. If one were to use a SDR (software defined radio) and that software included all the fourier transforms necessary to extract signals (and only valid signals) out of the noise (and all the other software tricks needed to put it all together), then there would be no noise to go to the speaker, only the signal.. That stuff costs big bucks. Why? Because they can. I have heard HF SSB radio that is absolutely silent unless a signal is present; it is like a squelch, in the way it is perceived but there is no control. Just quiet that is broken when a signal appears. It is like magic but I cannot afford it.

It's actually not that expensive. Even the lower priced ham radio HF rigs now have NR and DSP features.

The issue is simply that marine radios don't have the capabilities.

[IOM]

I have the DSP speaker from BHI and yes it works very well, definitely makes SSB as received by most basic HF radios more pleasant to listen to.
But you still get the noise from interference which kills the desired signal before you can hear it
Why you would think its snake oil, I don’t know. Hi end headphones use the same principle to create the illusion you are in a totally silent room, despite there being loud noise around you

The noise cancelling device works on the principle of receiving the noise from a short sensing antennae (in a boat maybe 6ft of wire inside the boat where the noise is generated) and noise and signal from the main antennae. The phase and amplitude of the small antenna signal is adjusted to be opposite phase, but equal amplitude to that of the large antenna, thus creating an audible “null” in the noise. It is not done automatically, so it does take some skill to operate,like anything in life, but its not difficult.
Yes if the small antenna is receiving the main antenna signal, it will cancel the signal you want to hear out as well, but the sense antennae is usually made to be such a poor antennae, that it can’t receive the distant station signal, but can receive the noise well enough to be useful in cancelling it out. Remember the noise is usually very strong.
As to how well Noise cancelling devices work on a boat, I don’t know …yet… but it sure works for noise in my suburb on electric fences, and power line noise, which is so bad, that HF radio work is near impossible. I don’t have a link to one, as mine was built by a local guy. And yes, they are not perfect, and do require some adjusting to get right, but it does kill the noise to make the radio able to receive again. I believe there are commercial ones, if you have the money, or if you are handy, I have seen circuits on the www in the past.

[transmitterdan]

If SSB receivers were as numerous as say WiFi then it would not be so noisy. Technology exists to address the problem but not enough units are sold to justify the cost to develop and market a product. WiFi is also affected by interference but it is dealt with by technology such as MIMO and the like.

Also, the sources of SSB interference are almost too numerous to mention. Power lines are a big problem as are certain common rail diesel engines. Power companies are causing harmful interference but the regulators do nothing about it because in today's world a working air conditioner, microwave oven, etc. is more important than SSB radio reception.

At sea the situation is much different. Interference comes primarily from your own boat and you can fix that. So away from shore SSB can be much quieter than when at the dock.

[S/V Illusion]

Again, it's not an issue of cost evidenced by the efficacy of NR and DSP in most cheap ham radios.

Regarding the after-market noise canceling speakers, these inherently are audio NR circuits which are effective only in limited conditions and not really amenable to helping the wide RF radiated noise afflicting boat owners.

The only effective way to minimize noise in contemporary marine HF radios is to eliminate the source(s).

[Cadence]

Originally Posted by S/V Illusion

Again, it's not an issue of cost evidenced by the efficacy of NR and DSP in most cheap ham radios.

Regarding the after-market noise canceling speakers, these inherently are audio NR circuits which are effective only in limited conditions and not really amenable to helping the wide RF radiated noise afflicting boat owners.

The only effective way to minimize noise in contemporary marine HF radios is to eliminate the source(s).

I'm as dumb as a rock. What about better shielding if we are speaking of onboard created noise. Noise cancelling speakers seem like an after the fact solution. JMHO

[S/V Illusion]

Originally Posted by Cadence

I'm as dumb as a rock. What about better shielding if we are speaking of onboard created noise. Noise cancelling speakers seem like an after the fact solution. JMHO

Never thought 'a rock' could ask a good question

Even if you could totally shield the radio itself, it wouldn't matter as most boat noise is radiated to be 'picked up' by the tuner, coax,feedline and antenna. Add that which can be conducted by the power cable and nothing is effective at everything.

What people try, sometimes with marginal success, is reducing the conducted noise with ferrites often using the wrong ones and audio noise reduction not designed to cure this problem of radiated noise.

Any radio which doesn't minimize RF noise at the IF frequency (first stage receive circuit) will suffer as everything after that stage is designed to amplify it (an over-simplification for purposes here). Marine radios aren't designed to discriminate what it amplifies like many ham radios can.

The best example can be observed when I compare my 802 with a relatively cheap Elecraft KX2 portable ham receiver. The former can't hear anything close to the Elecraft.

[trifan]

[QUOTE=IOM;2445753]I have the DSP speaker from BHI and yes it works very well, definitely makes SSB as received by most basic HF radios more pleasant to listen to.
But you still get the noise from interference which kills the desired signal before you can hear it
Why you would think its snake oil, I don’t know. Hi end headphones use the same principle to create the illusion you are in a totally silent room, despite there being loud noise around you

==========

That is an analog solution, old tech, archaic even. I wasn't referencing Jurassic solutions, I was speaking of purely digital means extending from the direct analysis of the radio spectrum to the signal extraction, all done by way of software. In these newfangled gadgets there is damn little in the way of actual "RF" hardware. Everything from adjacent channel noise rejection and interference to signal enhancement is all done using programming alchemy. It bears as much resemblance to traditional radio as a carburetor does to a multiport direct fuel injection system which, by the way, cannot work either without a lot of computing power running it. Using such an HF radio causes one to think they are on a cell phone, it is that good. Can you buy such a device on the market? Well, no, you cannot. Can a radio be bought with some of that tech in it? Yes and those half-way examples are several thousands of US dollars so, as I said earlier, those lab beasts are way out of my budget. In time, as this stuff gets paid down and the older radios get long in the tooth and all the money is squeezed out of them, you will see this tech show up more and more. At some point the Chinese will enter that market and play the "I can do it smaller and cheaper than you" game. I'm waiting for that.

[transmitterdan]

Trifan,

Noise canceling adapters for HF radio are not Jurassic solutions. They are in fact cutting edge digital devices that use sophisticated algorithms to filter out whines, pops and repetitive noise signals. They attempt to filter these annoying things out leaving the desired signal to be heard better.

There are also 100% software HF receivers on the market since about 20 years. Look for a USB software defined radio for the inexpensive Chinese device you are seeking. They are sold all over the Internet.

[tanglewood]

Well, I think I'm right back to the original question.....

It takes a Surrey Mystic to install an SSB with proper power supply filtering, data line filtering, cable routing, etc. to get something that works acceptably. That's for a $5000 radio.

But my Sat phone, or cell phone which costs hundreds of $$, not thousands, have no need at all for such kit gloves and baby treatment. And no need for soothsayers with divining rods to root out sources of interference. I turn it on and use it. Solutions to all the interference problems have been engineered into the product.

From the answers so far, even though the modulation technology is different, it sounds like the real answer is that we are dealing with dinosaur implementations of radios rather than a modern implementation.

[Wotname]

Originally Posted by tanglewood

Well, I think I'm right back to the original question.....

It takes a Surrey Mystic to install an SSB with proper power supply filtering, data line filtering, cable routing, etc. to get something that works acceptably. That's for a $5000 radio.

But my Sat phone, or cell phone which costs hundreds of $$, not thousands, have no need at all for such kit gloves and baby treatment. And no need for soothsayers with divining rods to root out sources of interference. I turn it on and use it. Solutions to all the interference problems have been engineered into the product.

From the answers so far, even though the modulation technology is different, it sounds like the real answer is that we are dealing with dinosaur implementations of radios rather than a modern implementation.

Your cellphone and/or sat phone can't connect to any other phone without infrastructure that costs hundreds of thousands / millions of dollars and every call is dependant on this infrastructure working each and every time.

The SSB marine radio only needs one other radio in order to communicate.

[transmitterdan]

Originally Posted by tanglewood

Well, I think I'm right back to the original question.....

It takes a Surrey Mystic to install an SSB with proper power supply filtering, data line filtering, cable routing, etc. to get something that works acceptably. That's for a $5000 radio.

But my Sat phone, or cell phone which costs hundreds of $$, not thousands, have no need at all for such kit gloves and baby treatment. And no need for soothsayers with divining rods to root out sources of interference. I turn it on and use it. Solutions to all the interference problems have been engineered into the product.

From the answers so far, even though the modulation technology is different, it sounds like the real answer is that we are dealing with dinosaur implementations of radios rather than a modern implementation.

Radio is radio. Your cell phone suffers from interference which the designers hide from your ears except when it disconnects for no apparent reason. A cell or satellite network costs billions of $ to build and maintain. An HF network consisting of only 2 radios can communicate over thousands of miles for about $5K all in. So HF is a pretty good deal by comparison.

HF radio uses one of the earliest known modulation methods (SSB suppressed carrier). But it is compatible with receivers that sell for $10 in many countries. Most people that complain about SSB interference never get out of the marina. They don't sail on long passages where HF SSB is the most useful and fun. At 100 miles off shore the noise goes down a lot because civilization is the source of most SSB noise (and a lot of other noise).

If you want to communicate with very high reliability for not a lot of $ learn morse code. It is way more robust than SSB voice.

But let's face reality. For most off shore cruisers a satellite tracker like Spot or a sat phone is perfectly fine for communicating with family and friends. HF SSB is good for making new friends you don't already know. Everything has its place in the world.

[trifan]

Originally Posted by transmitterdan

Trifan,

Noise canceling adapters for HF radio are not Jurassic solutions. They are in fact cutting edge digital devices that use sophisticated algorithms to filter out whines, pops and repetitive noise signals. They attempt to filter these annoying things out leaving the desired signal to be heard better.

There are also 100% software HF receivers on the market since about 20 years. Look for a USB software defined radio for the inexpensive Chinese device you are seeking. They are sold all over the Internet.

That is sorta true, as far as it goes. Those are NOT what I was referring to when speaking about the in-lab development systems I have had the pleasure of seeing which are an order of magnitude better than what is available on the market anywhere. Yes, I can go out and buy a SDR today from a variety of sources and pay prices as low as US$11 but, as one article on the web says, "SDR: It's all about the software". There are amateur sdr transceivers running in the $1500 price range on the net; there was one good performing system for about $6000 but none of these would do what I saw. So, yes, there is digital tech out there that is good, I do not deny that. All I was saying is that I saw stuff that made that tech look archaic. Think AI. Think magic.

[snokid]

you guys make it sound like finding the noise on your boat is hard.....

1st get out of the marina
2nd turn off all the breakers (except the radio lol)
noise should be gone. If not check antenna, and grounds...

now turn breakers on one by one
when the noise comes back figure out which item is making the noise, then either turn it off when you are using your radio or repair or replace it.

make sure while performing this test all your fancy electronics are off cell-phone, computers, tablets....

I know it's old tech, but so is that fancy cell-phone you might be using... do you remember the days of analog cell phones?

Get a hundred of miles off shore your choices for reaching someone go down SSB I still think is one of the best choices....

Bob

[Auspicious]

Originally Posted by snokid

you guys make it sound like finding the noise on your boat is hard.....

1st get out of the marina
2nd turn off all the breakers (except the radio lol)
noise should be gone. If not check antenna, and grounds...

now turn breakers on one by one
when the noise comes back figure out which item is making the noise, then either turn it off when you are using your radio or repair or replace it.

make sure while performing this test all your fancy electronics are off cell-phone, computers, tablets....

I know it's old tech, but so is that fancy cell-phone you might be using... do you remember the days of analog cell phones?

Get a hundred of miles off shore your choices for reaching someone go down SSB I still think is one of the best choices....

I agree with Bob.

It is worth noting that quieting rotating equipment is pretty easy, usually limited to adding capacitors and sometimes replacing worn brushes. Ventilation fans are the toughest since you often can't get to the motors. LC filters can work (ferrite beads and a capacitor).

Switching power supplies (invertors, including dedicated units in refrigeration; DC-DC converters; battery chargers; laptop power supplies; etc.) can be a bigger challenge. Poorly designed and engineered units might need shielding and remediation both inside and outside the unit. Replacement or powering off may be more practical.

Appliances (coffee makers, microwaves, digital clocks, and other items with digital controls) are often electrically noisy.

[tanglewood]

Originally Posted by Auspicious

I agree with Bob.

It is worth noting that quieting rotating equipment is pretty easy, usually limited to adding capacitors and sometimes replacing worn brushes. Ventilation fans are the toughest since you often can't get to the motors. LC filters can work (ferrite beads and a capacitor).

Switching power supplies (invertors, including dedicated units in refrigeration; DC-DC converters; battery chargers; laptop power supplies; etc.) can be a bigger challenge. Poorly designed and engineered units might need shielding and remediation both inside and outside the unit. Replacement or powering off may be more practical.

Appliances (coffee makers, microwaves, digital clocks, and other items with digital controls) are often electrically noisy.

I think you guys are missing the point. The problem is that I need to do anything.

To use my cell phome at home, I don't have to turn off all the power in the house. And I don't have to go through each circuit breaker to locate and suppress sources of inteference. All that is built into the cell phone.

I'm not askimg how to get rid of the noise. i'm askimg why the manufacturer hasn't done it for me in the design of the radio, like for every other radio based device that one buys today.

The answer seems to be "because". A little bit because AM is harder to deal with, but mostly it seems to simply be because they haven't done it.

It's kind of like the first PCs. If you didn't know someone who was a geek, you were SOL getting the thing to do anythhing usful. PCS evolved, but SSBs haven't.