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Re: [CQ-Contest] Noise Blanker recommendations

To: Charles Harpole <hs0zcw@gmail.com>
Subject: Re: [CQ-Contest] Noise Blanker recommendations
From: Ria Jairam <rjairam@gmail.com>
Date: Fri, 27 Oct 2017 13:30:46 -0400
List-post: <mailto:cq-contest@contesting.com>
Just throwing this out there:


FlexRadio Wideband Noise Blanker (WNB).

Yes, this video is real.

Best is to eliminate the noise source, but beyond that, SDR and DSP
can help a lot. I did a ride along with the cooperative identifying
arcing poles. I would still do that today.

I don't know if Anan has something similar but the only place I've
seen this kind of noise blanker is on a Flex.

Ria, N2RJ

On Mon, Oct 23, 2017 at 9:59 PM, Charles Harpole <hs0zcw@gmail.com> wrote:
> John, I have monster noise here near Bangkok and have tried several things.
> -ICOM IC-775dsp is jaw dropping good on radiated high voltage lines (it was
> made during the Russian woodpecker era), but can be defeated by other noise
> sources.
> -Yaesu FT-9000d has three built-in 'preselectors' ("RF u-tune" name) which
> are amazing on all kinds of noise but with strong noise, they lower the
> level but do not eliminate.  Astonishingly good on radiated noise, but not
> a total solution.  See
> https://www.dxengineering.com/search/product-line/yaesu-rf-mu-tune-kits-and-units/fits-transceiver-model/ftdx-9000/quantity/sold-individually
> .
> -K3 has about 16 settings for noise, all interwoven so that change one
> setting, it affects all the others.  Extensive adjusting of these will find
> one which works well but does not totally eliminate my noise (which is
> different at different times, requiring inordinate time to readjust).
> -ICOM IC-7800 seems better on some types of noise, like nearly knock out
> one kind while not too good on others.
> These radios I have personally tested side by side.
> The *best *solution is the MFJ 1025 "Noise Cancelling Signal Enhancer"
> because it is a phasing tuned unit requiring two antennas.  In my case with
> noise coming from NE, N, and NW only, this device absolutely eliminates my
> noise while leaving the desired signals untouched.  It requires only one
> session of adjusting, but has one astonishing draw-back: it will stand very
> little RF on the second antenna input so as to limit 1.5KW operation near
> its ants.... it needs a COR relay there.  Phasing is your answer because it
> really works.  The built in antenna on the MFJ-1026 was not tested.
> Of course there are a myriad of noise types and sources.  Mine are all
> radiated so the MFJ is great.  Noise coming thru the AC supply line have
> other solutions discussed elsewhere.  GL, 73, Charly HS0ZCW
> On Mon, Oct 23, 2017 at 9:27 AM, John Geiger <af5cc2@gmail.com> wrote:
>> I was making a rather serious (given my small antennas) effort today in the
>> Illinois QSO Party and had to deal with this intermittent noise I have here
>> for pretty much the entire contest.  It is a raspy, hash type noise that
>> will be on for 2 or 3 seconds, then will end, but come back every 20 to 30
>> seconds.  I  have figured out it is not in my house, and doesn't seem to be
>> power line noise.  At one time I thought I had localized it to a house
>> about 4 houses to the west of me, but the house is now unoccupied, but the
>> noise is still there.
>> Anyways, I was using the Kenwood TS950SD which I just picked up, and it is
>> a great rig with lots of receiver tools.  The noise blanker pretty much
>> knocked out the noise, but it also produced plenty of IMD products when the
>> band got busy and put a raspy sound on many of the signals, so I was having
>> to turn the NB off and on trying to make the signals as best as I could
>> with this noise.  Even engaged the attenuator a few times on 40m which
>> helped a little, but also weakened signals.
>> I have had a slight windfall recently and can afford to get a newer, better
>> rig if I want.  Are there any recent contest quality rigs that have noise
>> blankers that take out many different types of noise, but don't mess with
>> the receive signals and receiver dynamic range?  I wonder if the DSP based
>> noise blankers are better?  An older rig would be ok also if it would meet
>> those criteria.
>> 73 John AF5CC
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> --
> Charly, HS0ZCW
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