"Deek" wrote in message
...
Ed Cregger wrote:

SNIPPED

You are correct, of course. But there are instances where distortion
increases intelligibility. as I'm sure an EE knows in spades.

Ed, NM2K

Ed, of course you are correct. The problem with CB compressors and the
folks who use them is that they don't know or pay attention to the
reasonable limits.

My oldest son owns and runs an interstate long haul trucking business. I
have heard more garbage on 27.185 MHz from over compressed, over powered,
over distorted, off frequency, boosted radios while riding shotgun with
him than I care to recall.

Most audio 'power' is in the lower portion of the voice spectrum.
Increasing the mid range by 2 to 4 dB, adding 2 to 4 dB of audio spectral
distortion, does increase received intelligibility AND it does sound
un-natural. Also, increasing the average audio power output from 30% duty
cycle to 50 or 60% audio power output increases the thermal load on the PA
final and heat sink by 100% in SSB and by approximately 40-50% in AM. I
don't believe CB rigs have thermal designs for the heavier duty cycle.

When I chase DX on the ham bands I do not use compression. My transmitted
audio passband is 300 to 2400 Hz [IC 756 P3]. I have four HF radios
[IC756P3, IC746, IC706MKIIg, and KW TS570D] all with built in compression
capability.

If I can't work them on SSB I do it the easiest way possible ... CW [Don't
need compression on CW] :-)

I have heard so many over-compressed signals on 75 and 20 meters that I'll
turn on two meters and join a local rag chew or round table where we old
farts solve all the world's problems.


-------------------

One of the things that I liked about some Yaesu radios (haven't used them
all to know) was that obtaining robust/strong audio with my bassy, soft
voice was as simple as turning up the mic gain a bit so that it was just
entering distortion. This trick even works on my FT-690R and used to work
quite well on my FT-726R as well. Getting my voice to project through any
radio has been a constant struggle.

Later on, with the advent of the IC-706, I was able to get good
intelligibility by shifting the "window" a bit through the crystal filters.
This is simply a matter of a software adjustment.

Like you, I do not use speech processors. They seem to be "tuned" for voices
that are a tad higher in frequency than my voice, so are completely counter
productive when engaged.

I have a Robyn 520D CB set from 1977 that is paired with an EF Johnson
ceramic element mic. No, it does not match at all, but it can make any male
voice sound like the God Thor when they talk. I keep it around just to
remember how far we have come. G

Ed, NM2K

On Sep 14, 4:48 pm, Wes Stewart wrote:
On Thu, 13 Sep 2007 10:36:06 -0700, Telstar Electronics

wrote:

I'm hesitant to reply to this crap but I can't help myself.

Other Processors Have a Problem...
Other speech processors use a low-cost "audio clipping" approach to
achieve compression. While this method is economical for the
manufacturer, clipping distorts the original signal and sounds fuzzy
on the air.

Bafflegab.

http://k6mhe.com/n7ws/

Note 5.

Wes... the link you provided of the clipping processor... on the first
page of the article shows a THD distortion of 10%! That's low?... LOL
The VoiceMax processor has up to 60dB compression with less than 1%
THD @ 1KHz.
www.telstar-electronics.com

On Sep 14, 4:48 pm, Wes Stewart wrote:
On Thu, 13 Sep 2007 10:36:06 -0700, Telstar Electronics

wrote:

I'm hesitant to reply to this crap but I can't help myself.

Other Processors Have a Problem...
Other speech processors use a low-cost "audio clipping" approach to
achieve compression. While this method is economical for the
manufacturer, clipping distorts the original signal and sounds fuzzy
on the air.

Bafflegab.

http://k6mhe.com/n7ws/

Note 5.

Wes... the link you provided about the clipping type processor... on
the first
page of the article states a distortion of 10% THD. That's awful...
LOL
The VoiceMax processor has 15:1 compression with 60dB of dynamic range
and less than 1%
THD @ 1KHz. The VoiceMax is a quantum leap up in performance to ANY
clipping type processor.
www.telstar-electronics.com

IDIOT!

"Telstar Electronics" wrote in message
ups.com...

On Tue, 18 Sep 2007 06:00:41 -0700, Telstar Electronics
wrote:

On Sep 14, 4:48 pm, Wes Stewart wrote:
On Thu, 13 Sep 2007 10:36:06 -0700, Telstar Electronics

wrote:

I'm hesitant to reply to this crap but I can't help myself.

Other Processors Have a Problem...
Other speech processors use a low-cost "audio clipping" approach to
achieve compression. While this method is economical for the
manufacturer, clipping distorts the original signal and sounds fuzzy
on the air.

Bafflegab.

http://k6mhe.com/n7ws/

Note 5.

Wes... the link you provided about the clipping type processor... on
the first
page of the article states a distortion of 10% THD. That's awful...
LOL

Laugh all you want but clearly you don't understand what you think you
understand.

We are talking "communication" systems here not hi-fi. If the
intelligibility improves faster than the distortion due to
instantaneous peak clipping then that is a net positive.

As an aside, I actually did myself a disservice by defining the onset
of clipping at the point where a 3 dB input change gave a 2 dB output
change. This is actually quite a bit of clipping, which means that my
"15 dB" clipping is considerably higher.

At the usual operating level, distortion is much lower. Furthermore,
following publication Schureuer offered some justified criticism over
my use of the Plessey IC. This device was a source of some of the
distortion, which is actually multiplied by the subsequent clipping
process.

I later built a discrete compressor using a linearized FET as the gain
control element and also incorporated noise gating. Operationally, the
distortion was negligible and the performance was phenomenal.

But back to you.

Your (actually Analog Device's) circuit is an AGC system and cannot
limit instantaneous peaks. So following compression of a big peak,
the amplitude of subsequent signals is reduced. This is helpful in
preventing overdrive of subsequent stages and provides a marginal
improvement in "talk power" but it is nowhere as effective as true
peak clipping.

Sorry, those are the facts.

BTW, the Kenwood TS-870 (which I use) is widely acclaimed for its
audio quality and is arguably the most sought after rig by the "hi-fi"
SSB garglers. It uses split-band speech clipping.

"Radioisfun" wrote in message
...
IDIOT!

"Telstar Electronics" wrote in message
ups.com...


We know, it has been ripped apart on this newsgroup a few times. It's not a
good product. If fitted without using the correct alignment procedures and
test equipment it will ruin performance and cause splattering over the bands
and generate harmonics. Not many people who have the "really loud = really
far" mentality will know how to use test equipment, they tend to be the ones
with a lack of knowledge. Maybe the type who believe polishing the aerial
will lower the VSWR!
The circuit has no RF filtering for a start, it is not screened in any way,
it has a light that you will never see once the radio is put back together
and it will have no benefit over the microphone that was designed to operate
with the radio. It will cause distortion and harmonics unless the radio is
realigned using test gear. If you use that on AM/SSB you will sound
terrible, it is a waste of time. There is no way that the circuit
differentiates between a voice and background noises, so raising the level
many times and keeping it at 100% will mean that the sound will just be a
"noise". Compare that to a normal mic, audio nearer to it such as the
operator voice will be louder than what is in the background.
The product is out of date, has no market and probably would have been
better 20+ years ago.

I certainly wouldn't recommend it, from a radio engineers point of view.

On Sep 18, 5:30 pm, "AUUDDIIOOO" wrote:
Just wondered on what happened to the Power amp He had.

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. Unlike other companies, we will discontinue a product
before we will cost reduce it to a point that sacrafices quality and
reliability. Sometimes I just go back and look at the photos... just
for old times sake... http://www.telstar-electronics.com/d...9ABTCPhoto.htm
www.telstar-electronics.com

On Tue, 18 Sep 2007 22:40:24 +0100, "john lyon"
wrote:


"Radioisfun" wrote in message
...
IDIOT!

"Telstar Electronics" wrote in message
ups.com...


We know, it has been ripped apart on this newsgroup a few times. It's not a
good product. If fitted without using the correct alignment procedures and
test equipment it will ruin performance and cause splattering over the bands
and generate harmonics. Not many people who have the "really loud = really
far" mentality will know how to use test equipment, they tend to be the ones
with a lack of knowledge. Maybe the type who believe polishing the aerial
will lower the VSWR!
The circuit has no RF filtering for a start, it is not screened in any way,
it has a light that you will never see once the radio is put back together
and it will have no benefit over the microphone that was designed to operate
with the radio. It will cause distortion and harmonics unless the radio is
realigned using test gear. If you use that on AM/SSB you will sound
terrible, it is a waste of time. There is no way that the circuit
differentiates between a voice and background noises, so raising the level
many times and keeping it at 100% will mean that the sound will just be a
"noise". Compare that to a normal mic, audio nearer to it such as the
operator voice will be louder than what is in the background.
The product is out of date, has no market and probably would have been
better 20+ years ago.

I certainly wouldn't recommend it, from a radio engineers point of view.

I was composing a point-by-point response to this when I had a power
failure and lost it. I'm not about to redo it, but let me summarize.

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:

http://www.analog.com/en/prod/0,2877,SSM2167,00.html

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.
www.telstar-electronics.com

IDIOT!

"Telstar Electronics" wrote in message
oups.com...