VoiceMax Transceiver Speech Processor
 

On Sep 19, 12:58 pm, Deek wrote:
I'm sure they will acknowledge that it introduces controlled distortion.

I'm surprised at you... being a chief engineer and all... you should
realize that in this audio application we're talking strictly about
harmonic distortion. After all, that's what you can hear. In the
Analog Devices datasheet (page2)... this is given for the SSM2166 as
"Total Harmonic Distortion including internal chip noise" of typical
0.25%... and a maximum of 0.5%. These figures rival the finest audio
equipment!
www.telstar-electronics.com

VoiceMax Transceiver Speech Processor
 

Deek wrote:
Telstar Electronics wrote:

On Sep 19, 12:42 pm, Deek wrote:

I conclude that the VOICEMAX issue has died, has had the funeral and
now should
be buried.
Those who advocate high distortion levels and poor quality signals
can spend
their $$$ and buy it.
Those who prefer low distortion and clean sounding signals won't.
Let the trip to the cemetery begin.


Thanks for your conclusion. Maybe you should contact the engineers at
Analog Devices and explain to them that their SSM2166 chip is just
plain no good. I'm sure they'd be happy to hear from you... lol
www.telstar-electonics.com


I'm sure they will acknowledge that it introduces controlled distortion.
=====================================
Which for radio voice comms does not matter all that much.

Frank GM0CSZ / KN6WH

Telstar Electronics VoiceMax
 

On Wed, 19 Sep 2007 08:28:58 -0700, Telstar Electronics
wrote:

On Sep 19, 9:05 am, Wes Stewart wrote:
I am no fan of Telstar and his spam marketing on these groups and many
of his claims are BS.
That said, you seem to know little more about the subject than does
he.
BTW, to see the performance of this thing without the hype:

Wes, I'm curious... what is this "hype" you are talking about? I would
like to address that directly.


First why don't you address the spam marketing part?

Then you can simply look the word "hype" up in a dictionary. It's a
simple word with a more precise meaning than "fuzzy audio", for
example.

Telstar Electronics VoiceMax
 

On Sep 19, 1:29 pm, Wes Stewart wrote:
First why don't you address the spam marketing part?
Then you can simply look the word "hype" up in a dictionary. It's a
simple word with a more precise meaning than "fuzzy audio", for
example.

OK... just as I suspected... you have no legitimate concern.
www.telstar-electronics.com

What happened to the SkyWave 2879ABTC?
 

Hi,

On Wed, 19 Sep 2007 05:55:10 -0700, Telstar Electronics wrote:

The SkyWave 2879ABTC was discontinued because of a poor profit margin.

Raising the price was not an option?

Cheers,
__
Gregg

What happened to the SkyWave 2879ABTC?
 

On Sep 19, 3:01 pm, geek wrote:
Raising the price was not an option?

Raising the price is always an option but we felt that given the sales
level at the original price... that an increase wouldn't be practical.
www.telstar-electronics.com

What happened to the SkyWave 2879ABTC?
 

On Sep 19, 3:01 pm, geek wrote:
Raising the price was not an option?

Raising the price is always an option... but we felt it wasn't a
practical one in this situation.
www.telstar-electronics.com

VoiceMax Transceiver Speech Processor
 

Distortion is more than harmonic distortion.

If any output does not replicate the input in amplitude and frequency response,
there is distortion ... period!

If a 1 Vp-p pure sine wave swept between 300 Hz and 3000 Hz goes into a device
and produces an output of 2 Vp-p pure sine wave between 300 Hz and 3000 Hz there
is a uniform gain of 2 and NO distortion.

If a 1 Vp-p pure sine wave swept between 300 Hz and 3000 Hz produces 2 Vp-p at
300 Hz, then rises to 2.5 Vp-p at 1000 Hz and further rises to 2.8 Vp-p at 3000
Hz, the signal is distorted! The output is NOT a constant multiplier of the input.

Run the test I posted. Or run it against a spectrum analyzer. Or, simply admit
the output does not replicate the input. Lack of replication, in amplitude,
frequency response or internal non-linearity, is distortion.

A-D is specifying harmonic distortion ONLY.

Speech compression is the deliberate introduction of distortion [to provide some
desired result]

In the recording industry, when analog recording was the norm, the recording
studio distorted the recorded signal by the addition of 'pre-emphasis'. That is
shaping the frequency response to compensate for known frequency variations in
the recording media. The playback electronics may have had 'de-emphasis',
depending upon recording media, to remove the effects of pre-emphasis and media
distortion so that the output replicated the input. That is controlled
distortion to achieve a desired result.

Speech compression in radio-telephony is intentional distortion to achieve a
perceived desired result.

In mathematical terms TD = THD + dA/dF + dA/dT + dA/dV + d(Af(F))/dF ... should
I continue?

TD = Total distortion
THD = Total Harmonic Distortion
dA/dF = Intentional Amplitude variation as a function of frequency
dA/dT = Amplitude variation as a function of temperature
dA/dV = Amplitude variation as a function of bias voltage [AKA common mode, bias
effects]
d(Af(F))/df = Amplitude and gain variations as a function of gain roll off of
the active device [a function of device gain rolloff [AKA gain*bandwidth product]].

I can add some more terms if you like.

As a Chief Engineer I know and understand exactly what I am stating.

A speech compression circuit deliberately produces a dA/dF, a variation in gain
as a function of frequency, to achieve an intended result. It is distortion!

As a company advertising and marketing a device, you should be precise in your
language or define your terms explicitly.

As far as I'm concerned this topic is dead, the funeral has been held, and the
grave has been covered. I have no need to defend myself.

Deek




Telstar Electronics wrote:

On Sep 19, 12:58 pm, Deek wrote:

I'm sure they will acknowledge that it introduces controlled distortion.


I'm surprised at you... being a chief engineer and all... you should
realize that in this audio application we're talking strictly about
harmonic distortion. After all, that's what you can hear. In the
Analog Devices datasheet (page2)... this is given for the SSM2166 as
"Total Harmonic Distortion including internal chip noise" of typical
0.25%... and a maximum of 0.5%. These figures rival the finest audio
equipment!
www.telstar-electronics.com

What happened to the SkyWave 2879ABTC?
 

The SkyWave 2879ABTC was discontinued because of a poor profit margin.
We hated to do it... but with the temperature compensating biasing...
and all the premium components and chassis... it was just too costly
to manufacture.

Why on earth would you put temperature compensating components
into this product. As far as I know no other doorstop on the market
uses them.

What happened to the SkyWave 2879ABTC?
 

On Sep 19, 8:53 pm, wrote:
Why on earth would you put temperature compensating components
into this product. As far as I know no other doorstop on the market
uses them.

Not temp compensating components... temp compensating bias.
www.telstar-electronics.com