Hello O2 Fans:
To quantify the issue a little better, my measurements show that the O2
produces an average power output that is about 3 db lower than the typical
imported radio. Even with the compressor set at 7, the O2 will produce about
20 to 25 watts average output at 70 watts PEP, while a Yaesu Mark V, with the
RF Clipper on and set at 4 to 5 db, will produce at least 40 watts or more when
the PEP output is 70 watts.
The ALC system in the O2 is entirely different from any off shore manufacturer.
It is so very fast to provide current limiting and protection for the finals,
not specifically to avoid overdriving an amplifier. This system provides
excellent final protection, but seems to limit the development of the transmit
envelope.
Of course, there are significant differences between an RF Clipper and a
Compressor. There alone, the differences are enough to easily see a difference
in average power, especially when driving an amplifier. Ten Tec seems to
prefer the lower distortion of a compressor, as opposed to slightly higher
distortion and more average power output with a Clipper.
I have experimented with changing the time constants in the hardware ALC for
the O2. By the time I got the average power output increased, the signal
already had begun to distort. If indeed this is the issue, the timing changes
will have to come from the software side. There are probably also reasons for
the ALC to be this fast in regards to the DSP system in use.
The audio in the O2, even with the compressor set at 7 is very good, and very
strong. It works well in pile ups, and is very distinctive sounding. The
system works as Ten Tec wanted it to. My amplifier clearly doesn't need to
work as hard when being driven by the O2, and maybe that isn't such a bad thing
after all.
BTW, I see the new K3 will indeed use a RF Clipper.
73 and Happy DXing,
Mike
W2AJI
> From: ronc@sonic.net> To: tentec@contesting.com> Date: Tue, 5 Feb 2008
> 13:48:12 -0800> Subject: Re: [TenTec] ORION II the right rig for SSB ?> > I
> agree with Merle that the sound of the processing is among the best out >
> there, but most operators notice that Orion's don't seem to drive a linear >
> as hard as most other rigs. I looked at the waveform for quite some time on
> > a spectrum analyzer and I believe that the problem is due to instantaneous
> > and absolute ALC action (and possible over reaction) on even the most >
> fleeting peaks. This results in a lower observed average output although >
> the peak output appears to be correct. The lower average output probably >
> has little effect on the overall intelligibility of the signal or its >
> ability to bust through a pile-up, but this is an area that could use some >
> more study.> > Ron N6IE> www.N6IE.com> > > ----- Original Message ----- >
> From: "Merle Bone" <merlebone@charter.net>> To: <tentec@contesting.com>>
> Sent: Tuesday, F
ebruary 05, 2008 10:20 AM> Subject: Re: [TenTec] ORION II the right rig for
SSB ?> > > > Ben (ON5GQ) said:> > "In the archives of this reflector and
reviews on Eham I found also > > negative> > comments regarding the average SSB
power output of the Orion II."> >
---------------------------------------------------------------------------------------------------------->
>> > Ben, like many other recent DSP based rigs, the Orion/Orion II V2 code
has > > been> > "work in progress" for some time. There was a point in the
firmware > > releases where,> > in my opinion, the V2 speech processing was not
great. However, that has > > been fixed> > and I now believe that the current
V2 speech processing is among the best > > I have> > ever seen.> > See post > >
http://lists.contesting.com/archives//html/TenTec/2007-05/msg00478.html> >> >
The Orion/Orion II V2 speech processing algorithm delivers 15-20dB of > >
compression with> > solid high quality speech. I think it represents a real a
dvantage for SSB > > contesters> > or DX'ers.> > 73, Merle - W0EWM> >
_______________________________________________> > TenTec mailing list> >
TenTec@contesting.com> > http://lists.contesting.com/mailman/listinfo/tentec> >
> > _______________________________________________> TenTec mailing list>
TenTec@contesting.com> http://lists.contesting.com/mailman/listinfo/tentec
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