[TenTec] [Orion] Orion II Noise Blankers

Grant Youngman nq5t at comcast.net
Sat Feb 25 16:22:41 EST 2006


> 2.	For me, the hardware NB works somewhat but the s/w NB does
> nothing. 

I suppose it depends on the characteristics of the noise.  I have a very
strong pulse noise in my neighborhood (don't know from what, it's a strong
"pop" about once per second) and both the HW and SW NB's take it out
perfectly.  But my noise isn't your noise, and luckily the power company
fixed the arcing insulator on the pole pig behind my house a couple of years
ago.  THAT was NOISE :-)

> The DR is what does nothing for me. It operates, but it makes 
> the signals much less intelligable on SSB for a neg negative, 
> and is simply makes copying cw signals impossible in some 
> cases. I can't even use it. 

Did you mean NR? I hear a little distortion on SSB.  I can't say I've found
it makes signals "much less intelligible".  For SSB I run it at "1" or "2"
almost all the time, and it cleans things up very nicely.  There is some
distortion.   I'd rather listen to a little of that than the watery sound of
the typical external LMS noise reducer, although I hope it gets cleaned up
in a future release.

I spent some time rereading the manual again, and it reconfirmed some
comments I made earlier.  Which is that on CW, if you're already using a
narrow filter, the NR may not add anything, and may in fact make things
worse.  That's partly because the NR is effectively nothing more than
another very narrow filter around the CW signal.  And partly because it's
effectiveness can be diluted if threshold is set to a high value, either
explicity in the menu or if RF gain is reduced.  The manual is pretty clear
on this, and has a reasonable discussion about when it will and may not be a
plus to use NR, how to set threshold and NR levels for best performance,
etc.  It's function is to improve S/N ratio, not get rid of the noise.

Interestingly, the II manual indicates that Threshold is automatically
reduced when NR is turned on, and although that did happen in the Orion
1.xxx and was very obvious, it isn't obviously occurring in the II.  The
radio behaves like that isn't happening at all.

Grant/NQ5T




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