VoiceMax
"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
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