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Noise in the Mideast

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Vic Rosenthal

Noise in the Mideast

Since getting on the air from Israel I notice an interesting noise on
the bands 7 and 10 mHz and to a lesser extent on 14 mHz. It is a
wideband 'schmutz' (technical term) which can take from 10 to 50 or 100
kHz. Its amplitude drops of gradually as you move away from the center.
It reaches S9 levels sometimes on 7 mHz.

It does not look like the typical switching supply noise. I do not hear
it on 3.5 or 1.8 mHz.

The K3's DSP noise blanker seems to help a little, but not much.
Does anyone know what it is? Could it be some kind of spread spectrum
transmission? It could be coming from anywhere in Europe or the Mideast.
--
73,
Vic, K2VCO/4X6GP
Rehovot, Israel
http://www.qsl.net/k2vco/
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Peter g3smt

Re: Noise in the Mideast

There are a number of similar transmissions that sweep about20 or 40kHz
but spread because of the short rise time of the modulation. These are
over the horizon radar systems that on analysis appear to be very
similar to those from 20 years ago.
73

Peter

G3SMT

On 12/10/2014 18:03, Vic Rosenthal K2VCO wrote:

> Since getting on the air from Israel I notice an interesting noise on
> the bands 7 and 10 mHz and to a lesser extent on 14 mHz. It is a
> wideband 'schmutz' (technical term) which can take from 10 to 50 or
> 100 kHz. Its amplitude drops of gradually as you move away from the
> center. It reaches S9 levels sometimes on 7 mHz.
>
> It does not look like the typical switching supply noise. I do not
> hear it on 3.5 or 1.8 mHz.
>
> The K3's DSP noise blanker seems to help a little, but not much.
> Does anyone know what it is? Could it be some kind of spread spectrum
> transmission? It could be coming from anywhere in Europe or the Mideast.

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JayR

Re: Noise in the Mideast

In reply to this post by Vic Rosenthal

Might be this

https://medium.com/war-is-boring/iran-can-now-detect-u-s-stealth-jets-at-lon
g-range-765efd6253e2

73

K2TTT (Jay)C6ATT

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Merv Schweigert

Re: Noise in the Mideast

In reply to this post by Vic Rosenthal

There is Chinese Hainan Island radar that is very active, and usually on
7MHZ.
it covers 100KHZ at least, the "smaller" 10khz wide signals are also
radar, over the
horizon, the smaller ones usually are several seconds of signal then
space and
repeat.. the Hainan dragon is constant on all the time when operating.
it is over S9 here on 40 when its on...
Not sure if thats what your hearing or not, K3 blanker will not handle
it, helps a
little but not much, I asked Elecraft about it and they mentioned an
experimental
change of some components that may help, but I do not have the info and
have
not tried it.
73 Merv K9FD/KH6

Vic Rosenthal

Re: Noise in the Mideast

Thanks to all who responded. The Chinese radar seems to fit what I hear
best. I'll try to null it with my Pixel Loop (which, by the way, is a
great, quiet receive-only antenna:
<http://pixel-antennas.com/?page_id=31>)

On 12 Oct 2014 21:23, Merv Schweigert wrote:

> There is Chinese Hainan Island radar that is very active, and usually on
> 7MHZ.
> it covers 100KHZ at least, the "smaller" 10khz wide signals are also
> radar, over the
> horizon, the smaller ones usually are several seconds of signal then
> space and
> repeat.. the Hainan dragon is constant on all the time when operating.
> it is over S9 here on 40 when its on...
> Not sure if thats what your hearing or not, K3 blanker will not handle
> it, helps a
> little but not much, I asked Elecraft about it and they mentioned an
> experimental
> change of some components that may help, but I do not have the info and
> have
> not tried it.
> 73 Merv K9FD/KH6
>
>> Since getting on the air from Israel I notice an interesting noise on
>> the bands 7 and 10 mHz and to a lesser extent on 14 mHz. It is a
>> wideband 'schmutz' (technical term) which can take from 10 to 50 or
>> 100 kHz. Its amplitude drops of gradually as you move away from the
>> center. It reaches S9 levels sometimes on 7 mHz.
>>
>> It does not look like the typical switching supply noise. I do not
>> hear it on 3.5 or 1.8 mHz.
>>
>> The K3's DSP noise blanker seems to help a little, but not much.
>> Does anyone know what it is? Could it be some kind of spread spectrum
>> transmission? It could be coming from anywhere in Europe or the Mideast.

--
73,
Vic, K2VCO/4X6GP
Rehovot, Israel
http://www.qsl.net/k2vco/
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