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
>
>
> _______________________________________________
> 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
|