Frank Gilliland wrote:
Well, here's some more techno-babble:

Real-time or feedback type compressors such as the SMM2166 use a
comparator to create the control signal and results in a "knee" in the
response curve. But any curve that has a knee is non-linear and
results in harmonic distortion (same as "compression distortion" in
your RF amps). Because the harmonics extend beyond the limit of your
audio bandwidth you must therefore limit that distortion with filters.
Since filters are non-linear with respect to frequency, and since
audio is an extremely wideband application, some part of the loop
(usually the preamp) must compensate for the diminishing high
frequency response (yes, even when the audio is limited to 3kHz).
That's called "frequency compensation" and is something that must be
included in the design of any compression circuit (or amplifier). You
can try to soften the knee by slowing the response time of the control
signal, but that results in spikes at the output because some of the
signal sneaks through during the time delay. So no matter what you do,
distortion is just an inescapable limitation of these circuits. If you
want to learn more on the subject, get an education.

You're right... your response is nothing but techno babble. You need to
read the complete data sheet for the SSM2166
(http://www.analog.com/UploadedFiles/...s/SSM2166.pdf). It
faithfully reproduces an audio sinewave... but has an AGC. The harmonic
dostortion is less than 1% according to the spec. So far, my new design
is working well... and has constant audio punch level... no matter if
you whisper or yell into the mic Exactly what is needed! With the fast
attack/release of the noise gate feature.. this chip is fantastic at
blocking ambient background noise!

www.telstar-electronics.com

On 22 Dec 2006 06:10:17 -0800, "Telstar Electronics"
wrote in
om:

Frank Gilliland wrote:
Well, here's some more techno-babble:

Real-time or feedback type compressors such as the SMM2166 use a
comparator to create the control signal and results in a "knee" in the
response curve. But any curve that has a knee is non-linear and
results in harmonic distortion (same as "compression distortion" in
your RF amps). Because the harmonics extend beyond the limit of your
audio bandwidth you must therefore limit that distortion with filters.
Since filters are non-linear with respect to frequency, and since
audio is an extremely wideband application, some part of the loop
(usually the preamp) must compensate for the diminishing high
frequency response (yes, even when the audio is limited to 3kHz).
That's called "frequency compensation" and is something that must be
included in the design of any compression circuit (or amplifier). You
can try to soften the knee by slowing the response time of the control
signal, but that results in spikes at the output because some of the
signal sneaks through during the time delay. So no matter what you do,
distortion is just an inescapable limitation of these circuits. If you
want to learn more on the subject, get an education.

You're right... your response is nothing but techno babble. You need to
read the complete data sheet for the SSM2166
(http://www.analog.com/UploadedFiles/...s/SSM2166.pdf).


I've had it in my files since the chip first came out. Studied it
several times. Even used the chip in a couple designs.


It
faithfully reproduces an audio sinewave... but has an AGC.


Any linear amplifier will "reproduce" a sinewave. If it has AGC then
how "faithfully" that sinewave is reproduced depends on the time
constant of the AGC loop.


The harmonic
dostortion is less than 1% according to the spec.


That's for a 1kHz sinewave with 1:1 (no) compression. That's pretty
crappy even for a CB, and proves that -you- didn't read the complete
datasheet. For comparison, look at the specs of the CA3080.


So far, my new design
is working well... and has constant audio punch level... no matter if
you whisper or yell into the mic Exactly what is needed!


If that's the case then you set the feedback time constant too slow
and built yourself a CVA, not a compressor. Look at the scope and you
will see spikes.


With the fast
attack/release of the noise gate feature.. this chip is fantastic at
blocking ambient background noise!


Yes, it works very well at blocking signals. So does a switch. The
problems start when it begins -passing- signals. Didn't I tell you to
do your research?

Frank Gilliland wrote:
I've had it in my files since the chip first came out. Studied it
several times. Even used the chip in a couple designs.


It
faithfully reproduces an audio sinewave... but has an AGC.


Any linear amplifier will "reproduce" a sinewave. If it has AGC then
how "faithfully" that sinewave is reproduced depends on the time
constant of the AGC loop.


The harmonic
dostortion is less than 1% according to the spec.


That's for a 1kHz sinewave with 1:1 (no) compression. That's pretty
crappy even for a CB, and proves that -you- didn't read the complete
datasheet. For comparison, look at the specs of the CA3080.


So far, my new design
is working well... and has constant audio punch level... no matter if
you whisper or yell into the mic Exactly what is needed!


If that's the case then you set the feedback time constant too slow
and built yourself a CVA, not a compressor. Look at the scope and you
will see spikes.


With the fast
attack/release of the noise gate feature.. this chip is fantastic at
blocking ambient background noise!


Yes, it works very well at blocking signals. So does a switch. The
problems start when it begins -passing- signals. Didn't I tell you to
do your research?

Well... it seems you are much smarter than the engineers at Analog
Devices... LOL
They could sure use someone like you. Why don't you send them your
resume?

www.telstar-electronics.com

On 23 Dec 2006 05:46:50 -0800, "Telstar Electronics"
wrote in
om:

Frank Gilliland wrote:
I've had it in my files since the chip first came out. Studied it
several times. Even used the chip in a couple designs.


It
faithfully reproduces an audio sinewave... but has an AGC.


Any linear amplifier will "reproduce" a sinewave. If it has AGC then
how "faithfully" that sinewave is reproduced depends on the time
constant of the AGC loop.


The harmonic
dostortion is less than 1% according to the spec.


That's for a 1kHz sinewave with 1:1 (no) compression. That's pretty
crappy even for a CB, and proves that -you- didn't read the complete
datasheet. For comparison, look at the specs of the CA3080.


So far, my new design
is working well... and has constant audio punch level... no matter if
you whisper or yell into the mic Exactly what is needed!


If that's the case then you set the feedback time constant too slow
and built yourself a CVA, not a compressor. Look at the scope and you
will see spikes.


With the fast
attack/release of the noise gate feature.. this chip is fantastic at
blocking ambient background noise!


Yes, it works very well at blocking signals. So does a switch. The
problems start when it begins -passing- signals. Didn't I tell you to
do your research?

Well... it seems you are much smarter than the engineers at Analog
Devices... LOL


Maybe. Maybe not. But I'm definitely smarter than you. I understand
how the chip works and its intended purpose, which is not the same as
the objective of your hacked design -- to increase the talk-power of a
CB radio.


They could sure use someone like you. Why don't you send them your
resume?


Why don't you spend some time and effort to learn about this stuff so
you can build something good instead of hacking other people's designs
and hoping they sell?

Frank Gilliland wrote:
Why don't you spend some time and effort to learn about this stuff so
you can build something good instead of hacking other people's designs
and hoping they sell?

Frank, never hacked at anyones design. My designs are all original...
your designs are nonexistant... LOL

www.telstar-electronics.com

On 25 Dec 2006 08:07:13 -0800, "Telstar Electronics"
wrote in
. com:

Frank Gilliland wrote:
Why don't you spend some time and effort to learn about this stuff so
you can build something good instead of hacking other people's designs
and hoping they sell?

Frank, never hacked at anyones design. My designs are all original...


Right. Let's start with your earlier design, a 2-pill, push-pull
"linear" hacked from a Communications Concepts kit, which itself is a
hack from a Motorola datasheet; then when under pressure for a decent
bias circuit you hack a design from a ham's webpage on and refuse to
disclose the schematic. You start -this- thread by openly admitting
how you are hacking a "compressor" circuit from another ham. Yet you
maintain that none of your designs are hacked. I'm now convinced that
you have redefined the term "hacked" to suit your purposes, just like
you did with the word "linear", and will likely do with "compression".
Congratulations, you just graduated from the Presidential Academy of
Semantics.


your designs are nonexistant... LOL


And once again you're back to the "sour grapes" excuse..... you should
have stopped with the 'lying president' emulation.

Frank Gilliland wrote:
Right. Let's start with your earlier design, a 2-pill, push-pull
"linear" hacked from a Communications Concepts kit, which itself is a
hack from a Motorola datasheet; then when under pressure for a decent
bias circuit you hack a design from a ham's webpage on and refuse to
disclose the schematic. You start -this- thread by openly admitting
how you are hacking a "compressor" circuit from another ham. Yet you
maintain that none of your designs are hacked. I'm now convinced that
you have redefined the term "hacked" to suit your purposes, just like
you did with the word "linear", and will likely do with "compression".
Congratulations, you just graduated from the Presidential Academy of
Semantics.

Frank, you evidently think that once an IC or transistor is used in a
design... that if someone else uses that same transistor or IC... that
the new design has hacked the existing one.
No wonder you never designed anything... LOL

www.telstar-electronics.com