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.