Noise, stupid noise! Intermittent noise!

Noise and interference issues?
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Alex Cator
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Joined: 26 Dec 2014 14:53
Location: East Harling, Norfolk, England (QTH JO02LK)
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Noise, stupid noise! Intermittent noise!

Post by Alex Cator » 26 Dec 2014 20:50

I have recently got an intermittent noise problem that happens every once in a while. Using whatever antenna, it comes in on my ST-SB920. Using a television antenna in the loft, and a One-For-All 10dB preamp, it is very severe. It makes BBC Radio Suffolk (semi-local on 104.6 that comes booming at 46dB strength, with full RDS and stereo, from Great Barton on the outskirts of Bury Saint Edmund's) have a little bit of static in the background and broken radiotext data, and Heart Norfolk from Stoke Holy Cross, booming at similar strength to Gt. Barton normally, has completely wiped out Radio Data System data and severe static, and similar problems to Stoke Holy X happen with Great Massingham. Everything else, including tropo signals, have severe static that's still there in mono, and very weak signals are hardly there at all. Tacolneston nationals are not affected, and hardly at all is Kiss in Mendlesham. If BBC Suffolk is affected, then oh no, since that's only 20 miles away, and, as a DXer, I listen to signals from hundreds and even thousands of miles away from my QTH. The Philex ribbon wire antenna that I used to use gets the noise at about 19 dB, and I had my Triax FM 3 antenna on test in the study. That got it as well, but very weak, and pretty much anything will walk over it if it's that weak. I walked around the shack and the rest of the house, with my Tecsun PL-390, trying to figure where it was coming from. There was hardly anything. I wondered ages ago if it was a fault with my tuner, and then I noticed it on the Tecsun, so it wasn't that, and it was not a preamp fault since it was there without the preamp, and I forgot it was on the Tecsun. The noise happens at a 10:2 ratio, or in other words, it happens for ten seconds and stops for two seconds, then comes back, and that all continues as a cycle, until it stops. On the PL-390, it was coming from somewhere behind the tuner, and the TV antenna is up above all that in the loft, maybe why it gets it, and the tuner does not cause it since it needs an antenna to be heard. It must be from a neighbour's house, since houses on a different street are behind my garden. What kind of device is responsible for intermittent noise that happens for ten seconds, stops for two seconds, then it comes back and does that cycle for ages? The noise is about 32 dB at its peak and could make Heart in Madingley, which is 21dB, have stupid levels of static over it at 42 dB.
Home: Sony ST-SB920 (modified), Sony XDR-S10HDiP, Onkyo T-4970, Ford 5000 RDS, horizontal Triax FM3
Mobile: Ford Fiesta (Style, 2013) and Ford Focus (2012) car radios
Portable: Tecsun PL-390, Grundig G5 (2 x 110kHz), Etón G8

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John Faulkner, Skegness
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Location: Skegness, Lincolnshire. JO03dd
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Re: Noise, stupid noise! Intermittent noise!

Post by John Faulkner, Skegness » 27 Dec 2014 13:18

The number of people who avoid noise these days are very few and far between. In more extreme cases even rural locations can have noise issues from sources several miles away. We will all experience some degree of noise in our DXing.

Are you certain that the noise is coming from a neighbour and not from your own property? I know that's potentially an insulting question as you have obviously done some research, but I know from experience that it's easy to miss something which is emanating from right under your nose. When your folks are out and the video is not recording, could you switch off the mains electricity supply to the house at the main control box, just for a few seconds, so you can walk around the house with a portable radio and see if the noise has gone?

If possible, you need to get an antenna outside your property. I know from tough experience how difficult it is with issues of planning permission or neighbours, but a hidden antenna outside, away from the house, can be more effective than a beam in the loft. I used to have moderate noise across the FM band, such that it obliterated any weak DX and made a mess of moderate signals. It was occasionally audible in the background on national Belmont stations too. Then add the problems we had with planning permission and violent neighbours - hopefully yours are OK.

Could you try a half wave dipole outside? Or, if you are able to try this, I can recommend an FM loop antenna: http://skegnessdx.blogspot.co.uk/2014/1 ... tenna.html Believe me, in some respects this works as well as some three or four element dipoles, especially if they are in the loft.

Andrew Webster,Wigan
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Joined: 18 Sep 2014 16:03
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Re: Noise, stupid noise! Intermittent noise!

Post by Andrew Webster,Wigan » 27 Dec 2014 15:18

Very good advice form John there I have had for some while a buzzing noise around 87.5-8 very faint and drifts around but DX soon pushes that out of the way.
I discovered this noise is coming from one of my PC monitors so it shows that QRM can be created in your home as well as others.

As John said loft aerials don't work as good as outside ones do.

Andy
Receiving equipment: 2 Sony ST-S311, 1 Sony ST-SE520, 1 Sony ST-SE700 2 crossed FM 5s rotatable, 1 homemade FM 3 horizontal beaming S/E, 1 vertical FM 3 fixed beaming at Ireland, 2 element band 1.

Alex Cator
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Joined: 26 Dec 2014 14:53
Location: East Harling, Norfolk, England (QTH JO02LK)
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Re: Noise, stupid noise! Intermittent noise!

Post by Alex Cator » 28 Dec 2014 18:27

I own a Triax FM3 antenna. I have yet to get a tripod for it, but when I do, I will test it with my Sony ST-SB920. I am soon probably going to get an Onkyo T-4970 tuner, and a Sony XDR as well. My XDR will probably be the XDR-S10HDiP, because the cheapest XDR on eBay was an S10HDiP, despite the fact that I have no use for the Apple dock, even though there may be an F1HD or S3HD on there too. I think I will have no more noise, since my front garden is in the opposite direction to the noise. My Triax will be facing towards the IJsselmeer in the Netherlands. Only thing is that it's facing the road, but I live on a cul-de-sac and that is hardly a problem because of hardly any cars.
Home: Sony ST-SB920 (modified), Sony XDR-S10HDiP, Onkyo T-4970, Ford 5000 RDS, horizontal Triax FM3
Mobile: Ford Fiesta (Style, 2013) and Ford Focus (2012) car radios
Portable: Tecsun PL-390, Grundig G5 (2 x 110kHz), Etón G8

Alex Cator
Posts: 644
Joined: 26 Dec 2014 14:53
Location: East Harling, Norfolk, England (QTH JO02LK)
Contact:

Re: Noise, stupid noise! Intermittent noise!

Post by Alex Cator » 31 Dec 2014 15:53

I did some direction finding yesterday with my Tecsun. I faced it out of a window, towards a neighbour, and it was not coming from there. In fact it had nothing to do with a neighbour. It was directed to a radiator in my own house. With the Tecsun's antenna on a radiator, I could hardly hear Heart Bury St. Edmund's on 96.4 at all. How could it come from a radiator?
Home: Sony ST-SB920 (modified), Sony XDR-S10HDiP, Onkyo T-4970, Ford 5000 RDS, horizontal Triax FM3
Mobile: Ford Fiesta (Style, 2013) and Ford Focus (2012) car radios
Portable: Tecsun PL-390, Grundig G5 (2 x 110kHz), Etón G8

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