[TenTec] ORION II the right rig for SSB ?

[Mike Schatzberg]

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 at sonic.net> To: tentec at 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 at charter.net>> To: <tentec at contesting.com>> Sent: Tuesday, February 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 advantage for SSB > > contesters> > or DX'ers.> > 73, Merle - W0EWM> > _______________________________________________> > TenTec mailing list> > TenTec at contesting.com> > http://lists.contesting.com/mailman/listinfo/tentec> > > > _______________________________________________> TenTec mailing list> TenTec at contesting.com> http://lists.contesting.com/mailman/listinfo/tentec