Bob,
Concerning the 2.8 KHz bandwidth, I purchased a used IC-781, and someone
had replaced the 2.8 bandwidth filter with a 3.3 KHz unit. I am
converting it back to stock, anyone need a wiiiide SSB filter for an
I***?
Barry
-----Original Message-----
From: tentec-bounces@contesting.com
[mailto:tentec-bounces@contesting.com] On Behalf Of Robert & Linda
McGraw K4TAX
Sent: Thursday, February 16, 2006 9:10 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Hi Fi SSB
Yes and one can maximize the fidelity into the realm of violation of the
FCC
regs. I for one have been in the SSB bandwidth vs. AM bandwidth debate
for
years. And yes, I run full carrier DSB otherwise Amplitude Modulation
at
1500 watts PEP. Simply stated, they are two different modes just like
SSB
and CW are two different modes thus two different bandwidths stipulated.
Guaranteed and fact; the definition of SSB is one which is reduced in
bandwidth for efficient communications. One will only get a certain
amount
of information through a 2.8 KHz bandwidth, I don't care how you shape
it or
compress it. Experiment all you wish but be prepared to justify your
results to the FCC. And in another persons words, "I can't think of a
reason that will be acceptable".
The bottom line, take any portion of the audio spectrum, send it through
a
2.8 KHz filter and you have 2.8 KHz of some portion of the audio
spectrum.
Be it 20 Hz to 2820Hz or be it 500 Hz to 3300 Hz or be it 2500 Hz to
5300 Hz
you still end up with 2.8 KHz of bandwidth. You pick how you want it to
sound. Have you ever wondered why the female voice sounds somewhat
different on SSB? It is the content of the voice vs. the section of the
audio spectrum processed.
The SSB spectrum was developed for the typical male voice which has more
low
frequencies and fewer high frequencies as compared to the typical female
voice. I'd expect the ARGO V with its 500 Hz low end response and a bit
more high end response to sound quite good with the female voice. On
the
other hand, that's most likely why the concerns of the frequency
response
with the male voice are being expressed.
Now as to experimentation, if one wishes to develop a system that has a
S/N
ratio of better than 70 dB with a distortion of less than 0.01% and an
equal
quality detection system, then this is legal and is very much a natural
part
of the ham radio hobby. Have at it.
As to enhanced transmit frequency response requiring more bandwidth for
SSB,
don't go there.
73
Bob, K4TAX
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