Elad S2 2-Meter Reception


George Stein - NJ3H
 

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George


Paul NN4F
 

George,
What antenna you using for that range, and does it go away with antenna disconnected?

--
Paul Jones - NN4F EladUSA 
Email: paul@...
http://www.nn4f.com
http://www.facebook.com/NN4F.Radio
http://www.facebook.com/groups/sdrplay
Twitter: @nn4f_radio


On Aug 10, 2021, at 17:14, George Stein - NJ3H via groups.io <nj3h@...> wrote:

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George
<Screenshot-2021-08-10-140656.jpeg>


George Stein - NJ3H
 

Hi Paul, 

It is a circular FM (88 to 108) antenna. Yes, the QRM goes away with no antenna connected. I realize not a great antenna, hut I did decode the ISS on packet today with it. 



Thanks for your reply. 


On Tue, Aug 10, 2021 at 2:46 PM, Paul NN4F
<paul@...> wrote:
George,
What antenna you using for that range, and does it go away with antenna disconnected?

--
Paul Jones - NN4F EladUSA 
Email: paul@...
http://www.nn4f.com
http://www.facebook.com/NN4F.Radio
http://www.facebook.com/groups/sdrplay
Twitter: @nn4f_radio


On Aug 10, 2021, at 17:14, George Stein - NJ3H via groups.io <nj3h@...> wrote:

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George
<Screenshot-2021-08-10-140656.jpeg>


jdow
 

Considering it is optimized for broadcast FM you can expect it to be comparatively numb on 2 meters. But, still, you have that noise. Isolating it is often not easy considering that there may be multiple sources.

{^_^}

On 20210810 15:53:42, George Stein - NJ3H via groups.io wrote:

Hi Paul, 

It is a circular FM (88 to 108) antenna. Yes, the QRM goes away with no antenna connected. I realize not a great antenna, hut I did decode the ISS on packet today with it. 



Thanks for your reply. 


On Tue, Aug 10, 2021 at 2:46 PM, Paul NN4F
<paul@...> wrote:
George,
What antenna you using for that range, and does it go away with antenna disconnected?


On Aug 10, 2021, at 17:14, George Stein - NJ3H via groups.io <nj3h@...> wrote:

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George
<Screenshot-2021-08-10-140656.jpeg>

Screenshot_20210810-155214.png


Simon Brown
 

George,

 

This is QRM, possible from your house, I suggest a router or maybe your computer.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of George Stein - NJ3H via groups.io
Sent: 10 August 2021 22:14
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Elad S2 2-Meter Reception

 

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George


--
- + - + -
Please use https://forum.sdr-radio.com:4499/ when posting questions or problems.


Allan Isaacs
 

Hi George

I just took a street view look around Redmond and I wonder if an air conditioning unit might be responsible for the noise?

I notice you have lots of suppliers and one offers Daikan units which I assume is Daikin?

I was asked to sort out interference to VHF comms on a local ferry operating here on the Solent and it turned out to be from a Daikin air conditioner. To reduce costs they’d bought a standard commercial unit rather than one with a marine spec.

The thing used a chopper chip type STR-L472 which radiated VHF interference that was rock steady with one spike right on top of their ship-shore channel.

You have a lot of unsightly mains distribution cables around there and these may be radiating noise but if you can find a portable VHF radio and one of your interfering signals is stable enough you might be able to pinpoint its source?

http://www.radiomuseum.co.uk/emc.html

That particular pcb had tracking for lots of mains filtering but half was strapped over probably to reduce costs.

“But lots of other chopper power supplies are available”

Cheers

Allan G3PIY

 


From: main@SDR-Radio.groups.io [mailto:main@SDR-Radio.groups.io] On Behalf Of George Stein - NJ3H via groups.io
Sent: 10 August 2021 22:14
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] Elad S2 2-Meter Reception

 

Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?

I see a similar view using an RSP DX with SDRuno.

Any thoughts would be most welcome.

Regards,
George

 


Mag loop Simon
 

Hi George

Good luck with that..

If you have not already done this try below..

Car battery, no sdr but “ normal radio 2m ssb radio” ( normally easier to hear the noise on am/ssb than fm)
Turn off power to your house..does the noise go?? HOPEFULLY yes..( best to do this while Wife in the middle of watching tv for best effect. Guess how i know!)
If noise goes..unplug everything but power to house on..then one by one start switching things on intill you find offending item..INCLUDE all lighting!

Or if Simon is correct you could just first try router or pc..( if your lucky.)

Here..it was the fridge/ freezer..then the kids electric scooter charger then the dishwasher and washing machine ( even when off by the switch.. ok unplugged.) oh and a tv..

If not on your property then you have an issue..getting your neighbours to power down their houses is an ask, and then telling them to replace their offending equipment is a bigger ask..( leading to being asked to @£;8 off.)

If its not your property it could be mains bourne..in which case you can do things... if rf bourne then moving antenna may help..or a directional antenna..( pointing in clear direction.)

I have much experience of this..( i run 3 phaser boxes, 6 loop antennas, massive mains filtering, common mode chokes in coax etc..)

But remember your first job is to check your place! ( and hope its from there)


Other Simon g0zen


Max
 

On Tue, Aug 10, 2021 at 10:14 PM, George Stein - NJ3H wrote:
Please see the attached picture.

One will note the large amount of signals (I call it it interference) displayed across the portion captured.

Does anyone have a clue as to what might be causing this?
Hi George

The acid test is as Mag Loop Simon says. Turn off main power to house then look on SDR with battery powered laptop, also roaming with small whip antenna. Of course it could be coming from the laptop in worst case scenario, but not so likely I would say.

Regular intervals does look like the classic demon, switched mode power supplies. This can include your UPS if you use one? I had a Belkin UPS and it was quite a time before I realised it was by far the worst culprit for noise in my house. Made one huge racket. Dumped it and switched to sinewave unit from Cyberpower. That is whisper quiet. Cured that particular issue totally. So good I bought two, one as a backup purely for fibre broadband kit/network.

But yes, do the "house quiet" technique as the first stop. It's sometimes hard to track down a source inside the house because some (many) SM PSUs put RF on to the house wiring then it seems to be coming from everywhere. Then it's a case of turning off every PSU individually and then turning them on one by one. In my case this mostly resulted in a steady and gentle increase in noise, i.e. many of them were radiating something, and summed together quite a mess. To be fair I've found it a much greater issue on HF rather than at VHF. I think you are a bit unlucky to see this at that frequency. Also look at any LED lighting or security lighting.

By the way, not all SM supplies radiate. There are some (built to the correct regulations with good filtering) that are actually very quiet. Branded is not always a guarantee. Some of my worst offenders have been from Netgear.

Good luck and 73

Max