On Jun 11, 8:44*am, james wrote:
On Mon, 9 Jun 2008 06:25:33 -0700 (PDT), Telstar Electronics

wrote:

|On Jun 6, 4:17*pm, james wrote:
| On Thu, 5 Jun 2008 16:25:44 -0400, "Tio Pedro"
|| wrote:

|
| ||"Telstar Electronics" wrote in message
|
| ....
| | VoiceMax is really gaining momentum!
| | Radio operators all over the world are enjoying the Voicemax
| | advantage.
| | Since VoiceMax doesn't use audio "clipping"... your audio is loud AND
| | clear.
| | What a concept!
| |
| | See what VoiceMax can do for you at
| |http://www.telstar-electronics.com/voicemax.htm
| |
| |What is the dB advantage of this vs. RF clipping for SSB?
| |
| |
| |----------------------
|
| RF Clipping is superior to audio compression in SSB transmission. RF
| clipping will provide about 6dB improvement over audio compression
| alone.
|
| james
|
|James is correct... that the RF clipping technique is somewhat more
|effective. What he fails to mention is that it's more complex... and
|not easily installed into an existing radio. RF clipping also
|exihibits substantially more distortion. The VoiceMax installs
|easily... and provides tangible results.
|----------------

Actually as easy to design an RF Clipper as an audio compressor. True
it is a bit more difficult to install. Audio clippers can be external
to the transmitter and simpler to install and operate. A RF Clipper
will install as easily as your internal audio compressor. *

Personally I would take RF clipping over Audio compression any day
with SSB transmissions. If the post filters are good in enough RF
clipping, there is not significant difference in distortion.

james

But I was under the impression that RF clippers only work on SSB?...
and the installation involves tearing into the IF section?

On Jun 5, 4:26 am, Telstar Electronics
wrote:
VoiceMax is really gaining momentum!
Radio operators all over the world are enjoying the Voicemax
advantage.
Since VoiceMax doesn't use audio "clipping"... your audio is loud AND
clear.
What a concept!

See what VoiceMax can do for you athttp://www.telstar-electronics.com/voicemax.htm

Here we go again!

Laura Halliday VE7LDH "Non sequitur. Your ACKS are
Grid: CN89mg uncoordinated."
ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer

Laura Halliday VE7LDH * * "Non sequitur. Your ACKS are
Grid: CN89mg * * * * * * * * * *uncoordinated."
ICBM: 49 16.05 N 122 56.92 W * * * - Nomad the Network Engineer

Good to hear from you Laura. You can see a photo of the Voicemax
speech processor in a radio... right before the radio was buttoned up
at http://tinyurl.com/2t2usu

Telstar Electronics wrote:
Laura Halliday VE7LDH "Non sequitur. Your ACKS are
Grid: CN89mg uncoordinated."
ICBM: 49 16.05 N 122 56.92 W - Nomad the Network Engineer

Good to hear from you Laura. You can see a photo of the Voicemax
speech processor in a radio... right before the radio was buttoned up
at http://tinyurl.com/2t2usu

Appropriately, a CB radio, illegally modified. Only a CBer would fall for this
"Speech Processor."

Appropriately, a CB radio, illegally modified. Only a CBer would fall for this
"Speech Processor."

Laura,
Evidently there are many radio operators worldwide that don't share
your views...
Thanks for your comment anyway...

Appropriately, a CB radio, illegally modified. Only a CBer would fall for this
"Speech Processor."

Yes, VoiceMax is selling well. We are unable to keep up with the
demand at this time. These units are back-ordered until late August08.

"Telstar Electronics" wrote in message
...
Appropriately, a CB radio, illegally modified. Only a CBer would fall for
this
"Speech Processor."

Yes, VoiceMax is selling well. We are unable to keep up with the
demand at this time. These units are back-ordered until late August08.

sound more like the garbage that fell off of the BACK of the animal while it
was taking a CRAP. OH - wait a minute - "back-ordered" - that is the
convention that you go out and turn-around and order something?

Telstar Electronics wrote:
Appropriately, a CB radio, illegally modified. Only a CBer would fall for this
"Speech Processor."

Yes, VoiceMax is selling well. We are unable to keep up with the
demand at this time. These units are back-ordered until late August08.

Just another example of how many morons are passing the so-called "exams" these
days.

I bought a VoiceMax to see what it was all about, set it up per the instructions, and it did what it said on the tin, loud, clear audio.
The noise gate was useful in the mobile, being very effective at reducing road noise. This little device is extremely well built and works well within its design limits, being great for long winded local qso, the audio being very easy to listen to hour after hour. That said, it it is no match for any of the quality RF clippers mentioned, in a DX environment, nor was it ever intended to be.
It would be interesting if Telstar Electronics would produce a dedicated RF clipper and satisfy this end of the market, apart from Ten Tec, to the best of my knowledge, there's nothing else out there that works correctly.

Well, I went and looked. Pocket your money. It's just an Analog Devices SSM2166 ($3.00) cell phone microphone processor chip with $2 of added parts. This chip is not designed for the kind of benefit Telstar claims, but instead, just equalizes a mic output level to avoid overloading an A/D converter. I built up a processor using one, and you only sound louder if you're already pretty loud to begin with. It won't help you get heard better if you're weak. This is traditional for all compression-based processors. Good if you're an AM broadcaster and want to sound LOUD (as the Wikipedia article on audio compression says), but not useful if you're weak signal.

RF clipping is far more effective. It's been used in long distance phone calls for nearly 100 years and you never thought of them as being distorted, did you?

It can be done completely external: create an SSB signal, clip it, then demodulate back to audio. The whole thing goes between your mic and the radio's mic jack.

Past examples that were very good are the Drake SP-75, Ten-Tec 234, and Datong RFC. A Google search for any of them will get you the schematic and most can be built for less parts cost than this Telstar thing.

I am aware of only one that is presently available, by DF4ZS, but the audio samples on his website demonstrate that he's got his design wrong, as it's loaded with audio, not RF clipping. Maybe you can buy one of those, and fix the problem...it needs more dynamic range in the audio section.