30m QRM from 10.108.5 to 10.114.4

Old Reflector
1

I don’t know what is the source of a frequent, constant strong QRM on 30m band starting a few Kc over 10.108.5 going up to a spike on 10.111.6 and ending slightly before 10.114.4
The spike puts a maximum of S9+30dB on the S-meter of my Kenwood TS-940S with an inverted V dipole.
I had such QRM when living in Madrid, central Spain, I have it now living in Navarra at the central North of Spain and I had it when on holidays in Coruna at the North-West coast of Spain.
This QRM is very often there and I guess many of you have it too.
But it’s clear to me that not everybody have it, as many spots of US SOTA’s are within the frequency range of the mentionned QRM.
Just for information to all SOTA activators not having this QRM in their areas, let me tell you that if you can avoid the mentionned window from 10.108 to 10.115 for your SOTA and base activities, you might increase the chance of being called by some more stations, at least EA and probably some others in EU.
I wonder whether this QRM is suffered in many other areas and I would welcome other hams reporting about this.
Just for information, this mentionned QRM was there when I started writing this post and it had gone away by the time I finished and posted it.
Unfortunately, it will be back soon…
Looking forward to hearing from you.
Thank you and best 73,

Guru - EA2IF

2

In reply to EA2IF:

Hello Guru!

Here ther is not QRM or QRN on 30m. Maybe must be local QRM?

EA4CWN Alfonso

3

In reply to EA2IF:

Hi Guru,

30m is often plagued by commercial / military data traffic & I presume the QRM you are referring to is that currently centered on 10112 with a bandwidth of about 3Khz. (Present @ 1754z in IO83SS)

This is not as bad as some of the military traffic that can have a bandwidth of around 10KHz or more.

A good way to check if the QRM is local to you, or more widespread is to check if it is audible via one of the numerous Web based SDR’s such as the one below in the Netherlands.

http://websdr.ewi.utwente.nl:8901/

There are now many WebSDR’s covering many bands, many of which can be found here:

http://websdr.org/

Thanks & 73,

Mark G0VOF

4

Hi all
I have checked that band of noise, around 10.110-10.115 almost every day along these last 6 months or so. it can be heared in twente, andorra, and several SRD servers more around europe.
It seems not to be some kind of coded xmission, just noise, but of course it could be…
73 de Mikel

5

In reply to EA2CW:
Hi Mikel,
Thank you for your answer.
I’m glad to hear someone else is copying this QRM. It’s not just me due to some appliances at home or neighbor’s home or my own imagination :slight_smile:
It will probably be some military radar or something like that.
Best 73,

Guru - EA2IF