E-SSB

[Buckskinner33]

Well Hell, Why am I beating up a dead horse for? The way I read it I thought you was opposed to it!

I'm going back to my Island...People like me there.

N_Jay ... Your Kung -Fu is better then mine. I see your Point :arrow:
(wheres the bowing emoticons?)

 

[kb2vxa]

Hi again,

"Because of my limited understanding, I don't understand yet why you
couldn't modulate a signal using less than 2.8kHz by utilizing the same
digital circuitry found in a P25 transciever. That circuitry must take the
human voice (analog) and convert it to a digital signal before it is then
modulated. So why couldn't you put this circuitry before the modulation
stage in a SSB transciever?"

Without actually trying it I couldn't give you an accurate answer. Of course it can be done but what would the resultant bandwidth be since SSB in no way resembes FM or PM? Then again FM and PM have completely different characteristics and circuits are designed accordingly. For one thing, PM doesn't require pre-emphasis while FM does and both require de-emphasis in the receiver to obtain a decent signal to noise ratio. Then there is the question of FCC approval, there are several digital modes hams can't use as it is. Any modulation scheme must be rigorously tested and thoroughly documented before the idea is even presented to the FCC.

There are several posts here comparing commercial and public service (scanning) to Amateur Radio, apples to oranges. What we need is some sort of meeting of the minds between scanner and monitoring enthusiasts and hams, and none of this crap from other web sites with so many personal interpretations and opinions getting in the way. I see the same stuff more or less on the ham related forums, everyone has an opinion and so few have the facts.

Well, you don't need a degree in electrical engineering but it sure helps. (;->)

 

[N_Jay]

Hi again,

"Because of my limited understanding, I don't understand yet why you
couldn't modulate a signal using less than 2.8kHz by utilizing the same
digital circuitry found in a P25 transciever. That circuitry must take the
human voice (analog) and convert it to a digital signal before it is then
modulated. So why couldn't you put this circuitry before the modulation
stage in a SSB transciever?"

Without actually trying it I couldn't give you an accurate answer. Of course it can be done but what would the resultant bandwidth be since SSB in no way resembes FM or PM? Then again FM and PM have completely different characteristics and circuits are designed accordingly. For one thing, PM doesn't require pre-emphasis while FM does and both require de-emphasis in the receiver to obtain a decent signal to noise ratio. Then there is the question of FCC approval, there are several digital modes hams can't use as it is. Any modulation scheme must be rigorously tested and thoroughly documented before the idea is even presented to the FCC.

There are several posts here comparing commercial and public service (scanning) to Amateur Radio, apples to oranges. What we need is some sort of meeting of the minds between scanner and monitoring enthusiasts and hams, and none of this crap from other web sites with so many personal interpretations and opinions getting in the way. I see the same stuff more or less on the ham related forums, everyone has an opinion and so few have the facts.

Well, you don't need a degree in electrical engineering but it sure helps. (;->)

1) the quote button works real well.

2) can't quite figure out what you are trying to say, and how it relates to the post you quoted.

2)

 

[DaveNF2G]

Then there is the question of FCC approval, there are several digital modes hams can't use as it is. Any modulation scheme must be rigorously tested and thoroughly documented before the idea is even presented to the FCC.

If that is true, then the rules have changed significantly.

Any modulation scheme that fits within the bandwidth, is generated using sound engineering practice, and whose parameters are documented such that the FCC can monitor communications conducted via that modulation scheme if they choose, is generally permitted in the ham bands. (That includes P25-compatible digital on the VHF and UHF bands.)

Otherwise, how would the "experimentation" take place that is part of the Basis and Purpose of amateur radio? The only thing we are not permitted to use, and which is often confused with modulation modes, is encryption.