[TenTec] Orion V1 Noise Reduction Settings

[Merle Bone]

Grant (NQ5T) said:
"NR works in a variety of ways, including using LMS or some other adaption
algorithm to adapt the coefficients of an IIR or FIR filter, in the classic
Wiener filter noise reduction algorithm."
----------------------------------------------------------------------------------------------------- 
Grant,
I believe your comment is correct and my earlier comment was in error. The other documentation I have seen on V1, and early V2, DSP firmware simply described the NR system as an "adaptive filter system" and did not specifically indicate it was "predictive" (The earlier reference is still very helpful in understanding the concepts used in the Orion V1 noise reduction 
-----> http://www.doug-smith.net/kf6dx3.pdf <------- ). So I will stick with the story that in V1 and early releases of V2 the NR algorithm is an "adaptive filter driven by an LMS algorithm with some forward leakage." And, I like the way it works in V1 :-) I have no idea what is in the current release of V2, but I also would join in asking TenTec to provide a "Theory of Operation" document for the current Orion V2 code.  I agree that Doug's articles describing both the Orion  http://www.doug-smith.net/orion.htm 
and special areas like the "interaction of the analog and digital AGC  http://www.doug-smith.net/digitalagc.htm " helped in understanding the Orion V1 "Theory of Operation."

Although the V2 code has significantly redesigned the Orion radio (As pointed out in the ARRL review of the Orion II), and changed its performance, I agree that we are all "in the dark" with respect to the current  V2 DSP firmware design. It seems the hardware guys are willing to document their designs (Lots of schematics) but the software folks are not willing (Or able?) to even provide a current theory of operation or operating block diagram for the V2 firmware. Although I certainly can not "change the DSP code," I find that kind of documentation an important aid in trying to better understand operating problems/bugs and that it helps to "frame some diagnostic testing."
73, Merle - W0EWM