What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

On 24/02/15 12:47, gareth wrote:

What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Technical developments of new encoding techniques that reduce required
bandwidth, just as SSB improved over AM. You can get CODEC2 down to
way less than an SSB signal quite easily.

Technical developments of new encoding techniques that decrease the
S/N margin needed for successful communications.

Ability to send voice and data at the same time, over the same
channel.

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

Undoubtedly some are introducing digital technologies in an attempt to
increase market share (hence them not all being compatible with each
other), but there are many other reasons.

A lot of the next generation HF rigs will have some kind of SDR onboard
anyway (even if they have nice butons and knobs to use that we are all
used to)

Not everyone is going to want to get their hands dirty and code their
own transceiver, or even hook up PA's PTT Changeover relays, preamps
etc, so it's not as if the big manufacturers are going to be wiped
out by SDR. There will still be a market for "black boxes"


73s

Iain

"gareth" wrote in news:mchrrq$n83$1@dont-
email.me:

What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

Technical investigations for those with the requisite skill set. Isn't that
what you're always banging on about, OM? Inane babble (i.e. 95% of all
QSOs) is till inane babble regardless of whether it is transported by voice
or Morse code.

On 24/02/2015 12:47, gareth wrote:
What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

Bandwidth reduction for one.
If you can encode and compress speech sufficiently then you can use
less bandwidth in transmission.

Clarity. With duplex transmission it is possible to transmit clear
speech over a noisy channel assuming you use an error correcting and
retransmission protocol, self correcting codes techniques etc.

Band sharing. Multiple users can transmit on the same band assuming
adequate time-slicing and collision detection and traffic handling.

or just for the fun of doing it.

Andy

On 2/24/2015 7:47 AM, gareth wrote:
What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?




Because it's there!

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

I think that your question is too vague and that you are asking a question that isn't hard to answer, but isn't asked the right way.

If you are asking - what good is digital, in my opinion the reason for digital is only because public service went digital and the only reason why public service radio is going digital is because they ran out of bandwidth and they would like to simulcast voice and internet - 2 times the amount of bandwidth or more into the same allotted space as their analog allotments.

Why would ham radio want to go digital when we have all kinds of bandwidth that no one uses? I think a lot of it has to do with technology so advanced that it sells more - new radios. There is such a small percentage of people buying actual ham radios today that the manufacturers needs gimmicks to keep the flow of radios and technology going.

On the UHF / VHF side of things, the capture ratio is much better for digital vs analog, but analog has the ability to communicate in places where digital will not penetrate. In public service radio, when the ability to talk further is produced, the first thing they do is turn down the transmit power.

Anyone that has worked Part 90 radio will tell you that when the transmitters were tube, even if the load was not a true 50 ohm load, even if the antenna fell down, the tube equipment would either keep going or it would blow the tube and it wasn't hard to fix. With solid state, when something happens, the equipment fails and it is very costly to repair or replace.

On the amateur radio side of things, the people licensed today as amateurs are stupid compared to those licensed 50 years ago when an applicant had to draw circuits and had to know the difference between different types of tubes and had to have an electrical background just to pass the test.

Today, you get 10 points just for spelling your name right on the application.
We give amateur radio licenses to 5 year old kids with no knowledge of electricity.

If we deploy stupid amateurs that can't do anything - once their smart phones quits working, we have to supply them with radios that can do simple tasks such as giving GPS coordinates and sending simple text messages.
This is basically what the Yaesu System Fusion equipment does and D-Star - which is practically worthless, allows the users to link up digital repeaters - VOIP. Which doesn't really teach the users anything about real ham radio.
Unless it is my antenna talking to your antenna, you might as well use Skype or a telephone...

On the HF side of things, the only benefits I can see to using digital modes is that it allows you to send blocks of text and it allows you to work weak signals - below the signal noise floor that we can perceive.
It is great for working moon bounce and other things like that..

That is another thing that degraded amateur radio, because you don't need to know CW to operate digital modes. What happens when the computer fails or there is a problem with the program? The people trying to use the digital modes cannot communicate with each other. While CW might be antiquated, it works! Or problem is the CB'rs that we now license to occupy our bands so we don't loose our bandwidth doesn't know how to operate CW and doesn't want to learn and is too stupid to learn it on their own.

So the only alternative is to give them something that they can use that they don't have to learn how to do anything other then press some keys on a computer keyboard.

So in my opinion, the architect of this program was very ingenious to come up with modes to allow people to communicate with each other digitally that prolongs our hobby at least for a little while. It doesn't make the people smarter, but it does reduce the idle chatter and the lack of identification that I have observed on the phone bands elsewhere.

You don't normally see rag chewing on the digital portion of the bands.

"AndyW" wrote in message
...
On 24/02/2015 12:47, gareth wrote:
What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

Bandwidth reduction for one.
If you can encode and compress speech sufficiently then you can use less
bandwidth in transmission.

That's the bit I have trouble getting my head around. Back in the 1970s and
1980s digital transmissions used a much greater bandwidth than their
analogue equivalents. Sampling at 2.2 x max frequency x number of bits plus
housekeeping bits etc. etc.
A UK standard 625 line PAL video transmission would have used a bandwidth of
over 400MHz!
Times have changed and left me behind, but I've still got me beer so who
cares?
--
;-)
..
73 de Frank Turner-Smith G3VKI - mine's a pint.
..
http://turner-smith.co.uk

"Iain Young, G7III" wrote in message
...
On 24/02/15 12:47, gareth wrote:

What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Technical developments of new encoding techniques that reduce required
bandwidth, just as SSB improved over AM. You can get CODEC2 down to
way less than an SSB signal quite easily.

Those who subscribe to these digital voice apparatuses lack a single clue
about any underlying technical development

On 2/24/2015 11:32 AM, FranK Turner-Smith G3VKI wrote:
"AndyW" wrote in message
...
On 24/02/2015 12:47, gareth wrote:
What is the point of digital voice when there are already AM, SSB
and FM for those who want to appear indistinguishable from CBers?

Perhaps it is cynicism from the manufacturers who introduce such things
as they see their traditional highly-priced corner of the market
being wiped away by SDR technologies?

Bandwidth reduction for one.
If you can encode and compress speech sufficiently then you can use
less bandwidth in transmission.

That's the bit I have trouble getting my head around. Back in the 1970s
and 1980s digital transmissions used a much greater bandwidth than their
analogue equivalents. Sampling at 2.2 x max frequency x number of bits
plus housekeeping bits etc. etc.
A UK standard 625 line PAL video transmission would have used a
bandwidth of over 400MHz!
Times have changed and left me behind, but I've still got me beer so who
cares?

But you forget compression. For instance, unless there is a scene
change, the vast majority of a television picture does not change from
frame to frame. Even if the camera moves, the picture shifts but
doesn't change all that much. Why waste all of that bandwidth resending
information the receiver already has?

And voice isn't continuous; it has lots of pauses. Some are very
noticeable, while others are so short we don't consciously hear them,
but they are there.

And once you've compressed everything you can out of the original
signal, you can do bit compression, similar to zipping a file for sending.

There are lots of ways to compress a signal before sending it digitally.
About the only one which can't be compressed is pure white noise -
which, of course, is only a concept (nothing is "pure").

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

"Brian Reay" wrote in message
...
After all, if they haven't understood say, super regeneration, after 40
years, what hope is there for their understanding, say, DSP?

Put your money where your (big) mouth is and explain to all why a
super-regenerative receiver will not resolve CW or SSB, when the
oscilation, although quenched, is effectively amplitude modulated
by the quenching?