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Re: [TenTec] [Orion] Orion II Noise Blankers

To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] [Orion] Orion II Noise Blankers
From: "Ron Castro" <ronc@sonic.net>
Reply-to: Ron Castro <ronc@sonic.net>, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sat, 25 Feb 2006 13:43:34 -0800
List-post: <mailto:tentec@contesting.com>
Yesterday I cured a terrible noise problem I had here on 75 meters that used to come up in the evening and ran a solid S-9 and had been around for a couple of weeks. I went out in the mobile looking for and tracked it down to a small neon sign above Laundromat in a strip-mall 1.5 miles from my house. Up close, the noise went from the bottom of the AM broadcast band to well into VHF, including the aircraft band. The O2 noise blankers were unable to reduce the signals in any way.

I called the manager and told him about the interference and he agreed to turn off the sign until an electrician could look at it, and 75 was noise-free last night!

Off-topic...two nights ago, I was walking around with my 12-year-old son inside the Laundromat with a field strength meter tracking the noise, and when I walked out the door, I saw six cops walking briskly toward me, while more cop cars were screeching up in front of the building. Even the K-9 unit was there! Scared the crap out of me, but they weren't after me. They grabbed up two seeding looking dudes in the Laundromat and hauled them out in handcuffs. What a night!

Ron N6AHA

----- Original Message ----- From: "Grant Youngman" <nq5t@comcast.net>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Saturday, February 25, 2006 1:22 PM
Subject: Re: [TenTec] [Orion] Orion II Noise Blankers


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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