I am afraid to say you are not being fobbed off. Yes High voltage power lines (the 22k volts and above) will cause interference on any AM based radio.
Its not the car, or the car radio its the 22,000 very noisy very dirty mains power. It gets worse with weather, the state of maintenance of the insulators, how much rubbish the transmission company is multiplexing down the power line, what radio station you are listening too and what the local reception is like
you cant blame the car or the radio.
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"when tuned in to an AM Radio Station I get lound interference which normally obscures the broadcast and in sometimes is actually very loud, when I go under power lines. "
But RF, is the above acceptable? I listen to Radio 5 a lot, and Talksport when cricket is on and though there is a little buzzing under power lines, it never obscures the station. No interference otherwise except when I go past a particular local factory!
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read the bit where it says its variable, and dependent on the particular power lines involved. ALSO with Radio 5 its very dependent on where you are. ever had to tune between its two freqeuncies when traveling depending on where you go?
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OK, I did but surely Pezzer is saying that he gets interference "which NORMALLY OBSCURES the broadcast and in SOMETIMES is actually VERY LOUD, when I go under power lines" (my capitals - and I'm not shouting at you!). I know nothing about it but am merely stating that as a regular listener to AM I get no interference normally and only occasionally a bit of buzzing (not enough to obscure the station) under power lines. In fact, come to think of it, a couple of weeks ago we were stuck in a traffic jam on the A453 for an hour or so and were listening to R5 to get traffic reports without any interference while sitting outside Ratcliffe on Soar power station.
As V8man states above - why have AM if it's "normally" not listenable to?
And yes, I do occasionally retune to get best reception (flip channnel to keep volume the same) - Leeds it is better on 909, Midlands 693, swap near Barnsley, but on neither do I get buzzing.
Yours, puzzled as to why I get perfect reception on a (cheap?) factory fit radio but Pezzer doesn't. (Maybe excellent quality French electrics!!!!)
Phil
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But RF, is the above acceptable? I listen to Radio 5 a lot, and Talksport when cricket is on and though there is a little buzzing under power lines, it never obscures the station. No interference otherwise except when I go past a particular local factory!
Listening to cricket on the radio??? How boring must that be "he runs up, he throws the ball, he hits the ball"
You don't have a problem because you don't realise that you have actually fallen asleep!! :)
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"he runs up, he throws the ball, he hits the ball"
Even sadder, I sometimes listen to football, (he runs up he kicks the ball, he falls over, rolls around on the ground clutching his face in agony, shouting "send him off ref"), often rugby (he runs, he catches the ball, he passes the ball, someone else kicks the ball and England have won the world cup), and the Olympics (he runs) or (he pulls on the bit of wood, the bigger bit of wood goes fast through the water, he wins his 4th or 5th gold medal)
However, I do draw the line at Prime Ministers Question time, but even that will not persuade me to tune into Radio 1.
I am a saddo, but I like it and don't care what you think!!!!
Happy motoring!
Phil
P.S. Pity about the middle order collapse today. Still at least Vaughan got a few runs for a change (he hit the ball a few times and it was REALLY exciting)
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Buzzing under power lines is normal and unavoidable on AM -- the lines are 'transmitting' harmonics at a frequency in the broadcast AM bands, and the radio is doing what it was designed to do. You can hardly complain about that, and the dealer can do nothing about the laws of physics.
You cannot tune it out because the source is so close that the radio is swamped by the RF signal. You need to either get the power companies to rewire the national grid in shielded cable or use FM. FM was introduced nearly 40 years ago *specifically to overcome this kind of problem* (from RF interference in general), and yet we stubbornly refuse to use it. FM is now of course being replaced in its turn by DAB.
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Badger was previously registered as Stripey
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>>why have AM if it's "normally" not listenable to
FM is short-range broadcasting. AM is still needed for longer distances. Visiting France, UK FM fades out in the north, when you have to switch to LW AM.
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Badger was previously registered as Stripey
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This is unacceptable.
I listen to Radio 5 live and have no problems indeed. I can even listen to it reasonably well as far south as Tours, in France, when it then gets difficult to listen to properly.
Both my present car, an Accord, and my previous Omega, have aerials fitted in the windows. The Omega was in the rear windscreen, and the Accord has it fitted in the side windows - it's a tourer.
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I too find that the 'border' is around the Loire. FM is more 'line of sight' than LW, so it will be pretty consistent whatever the radio. By Avignon, I'm using short wave though not in the car of course.
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Listening to cricket on the radio??? How boring must that be "he runs up, he throws the ball, he hits the ball" You don't have a problem because you don't realise that you have actually fallen asleep!! :)
Spoken like a true Scotsman!
Actually the cricket commentary can be very entertaining - it used to be great.
At the last winter Olympics I listened to radio commentary on curling - WoW!
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Thanks Phil spot on, I'm listening to the same channels as you and am equally sad about the Cricket and Football.
I accept on AM that a little interference is likely, but not to this extent, especially when i am driving a far more expensive car than before in which I never had this problem.
( I'm not going to name the model because I dont want this to descend into the usual brand bashing contest.)
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It's quite possible -- though I have never tested it -- that a higher quality radio, through greater sensitivity, may actually exacerbate the power line problem. That greater sensitivity (together with better selectivity, which is nullified though by the swamping effect of power lines) is the same characteristic that gives you better long range reception than a cheapo set.
The wider you open the window, the more the muck blows in, as we used to say when I was in the RFI (radio-frequency interference) business.
Sorry Pezzer, I can fully understand your frustration but I can only refer the honourable gentleman to the reply I gave earlier.
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Badger was previously registered as Stripey
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May need some more detail from Pezzer. All AM stations affected or just some (try 693/909 and 198 and perhaps talksport)?. Does the interference stop with the engine off or co incide with particular ancilliaries running?.
AM is a bit of a minority interest and some manfrs respond by fitting poor quality AM stages into otherwiswe well specified kit. Finaly could the could the aerial be optimised in some way for FM?
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The optimum aerial length for FM is 32" (80 cm) which is also a fair compromise for AM as well. Such an aerial is actually a dipole, with the other half formed by the aerial's 'reflection' in the car's metal roof or bonnet. Maximum efficiency is achieved when the aerial is swung well away from the roof, vertical being the optimum. This is often impractical (garage entrances, etc) but at least swing it as far away from the roof as you can get away with. If there are telescopic sections, keep the joints clean as well as the attachment fittings and swivel points. A touch of WD40 does no harm.
A good point about AM stages, Bromptonaut, though this is likely to be as much a matter of adjusting the aerial trimmer in the set for optimum reception (it affects only the AM stage). Read the handbook on this.
The best performer I ever had on AM (as determined by distant reception in France) was a Sony radio/minidisc player, but it was as vulnerable to power lines as any other. Neon signs can be another external problem.
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Assuming your optimum is a 1/4 wave then yes thats about right for FM. Not sure about a fair compromise for AM. If you want a 1/4 wave for that (say radio 5 909khertz) you need one 83 metres high!
SO
From that we deduce that all car aerials are useless for AM.
Hence its unreasonable to expect perfect AM reception.
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Optimum for LW would be a long-wire aerial. 30 feet or so should do. Hmmm. Could be problems.
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Badger was previously registered as Stripey
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Yes Pezzer you are being ripped off.
In all my motoring, except when using a transistor radio, I have been able to listen to AM, which used to be MW, without interfearence. I would take your car back to the dealer and tell them in strong terms that you want it correcting. It souds to me that it might be the earthing on the ariel.
I listen to 5 live and talksport quite alot, and I sometimes enjoy football, rugby, criket and golf better on the radio than on TV. One can learn so much about red buses, chocolate cake, pigeans and all sorts of jolly japes.
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Pezzer, I meant "fobbed off", but I think that they might try to rip you off.
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No, quizman, AM and MW are quite different things. MW is the wavelength band, and AM -- amplitude modulation -- is the method by which the information in the signal is carried. LW, MW and SW are all on AM. FM is 'frequency modulation', the other way of carrying the information.
And I repeat what I said earlier, and which quizman probably hasn't seen. As a one-time engineer in that field, my advice is that power line interference is a fact of life on AM. The fact that it may vary under differing conditions does not alter that advice, but no-one has to take it. If his dealer doesn't know that then Pezzer may yet be lucky and swing a radio upgrade. Good luck to you Pezzer, but don't go to court. An expert witness would demolish this with ease, and it could prove expensive.
Wait till we have widespread broadband carried on power lines -- then we'll really know about interference.
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A line missed out. Sorry. The crunch here is that Pezzer's probem appears to relate only to power lines. A duff radio or installation would be prone to other interference also, particularly from the car's electrics. If it's otherwise OK then sorry, in my view he regrettably has no case.
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