Radio reception -- wtf?

JANDL100

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Why, in a poor reception area, does a car radio get a decent enough signal to use, but ordinary hifi tuners just get hissssssssssssss with an indoor aerial ? :?

 

bandit pilot

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It's because VHF is not that brilliant at penetrating brick and concrete. Add into that, the poured concrete prefab type houses, and you have a pretty good faraday cage. VHF is also pretty much line of sight, unless assisted by tropospheric propagation.

Just put a lump of metal in the air. Job done.

 

JANDL100

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Hmm, well, the dwelling I am talking about is a wood clad thing - and the car radio works fine when it is parked just a few yards away.

 

bandit pilot

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Hmm, well, the dwelling I am talking about is a wood clad thing - and the car radio works fine when it is parked just a few yards away.
There's always one. :doh:

Just tuck some bare wire under the cladding in a horizontal dipole configuration then. Wood is not a good insulator. :p

 

RobHolt

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The car radio has less focus on fidelity, therefore through a variety of measures including narrow selectivity, high sensitivity and making the signal effectively mono at HF it gives cleaner sound in areas of poor reception. Most hi-fi tuners employ wider selectivity, lower sensitivity and wide channel separation and this requires a better and stronger signal.

Wide stereo separation, low noise floor and very low distortion are far less important in the noisy car environment and so the technical compromise can be usefully shifted to making the tuner better with poor signals.

You can replicate this effect on a home hi-fi tuner by switching to mono on a weak broadcast - everything gets cleaner and noise drops.

If you want the best of both worlds, seek out a good top end Japanese tuner from 1975-1985. Pioneer, Trio, Hitachi, Technics and, the best IMO, Accuphase all made stunning tuners able to make the most of any conditions.

 
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pluto

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Rob has largely covered it. Car radios are remarkably good at discreetly reducing the stereo width (particularly at higher audio frequencies, which is where the hiss is) when the signal strength isn't up to it. The extra amount of signal required on FM to achieve the same noise performance in stereo as in mono is remarkably high (sometimes as much as 20dB, which is a lot).

You cannot work around the need to get metal in the air for decent FM stereo.

 

dfa2124

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The Denon TU-800L is my best tuner for it's combination of audio quality and RF performance (the Yamaha T-2 is better for sound but not quite as hot for really difficult signal capture). There are 3 IF bandwidths on this Denon and the 3rd one is superb for DXing or pulling out weak signals right next to strong ones. It's up there with the likes of the Onkyo T-9990 for DXing but apparently has better sound quality. As everyone is looking for TU-260s they can go for chump change on eBay if you are lucky.

Actually, the best tuner for DXing (can easily separate signals 100 kHz apart) is the Sony XDR-F1HD but everything sounds like a mid-fi MP3 so I rarely use it these days.

 
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stereo70

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My Marants ST6000 is complete pants, even with a roof aerial.

The car can pick up every station in the area.

To be fair my car radio isnt too shabby and sounds just as good as my Marantz, even better in fact because I can pick up stations on it!

Anyone wanna buy a marantz st6000?

 

cobbler

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Internet the way to go , sound quality is excellent these days ...... can be a distraction at roundabouts though, damn that Guess the album cover..

 

nat8808

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Personal experience is enlightened by Rob's post - some cheaper tuners seem to pick up stations better but sound very bland in doing so, with an almost mono effect.

Hey hiss always adds to the stereo effect and is not so bad on less interesting programs - it's stereo hiss afterall (i.e. different in each channel).

I'm lucky in that they installed an integral TV/FM, estate wide aerial system back in the 70s when they built the place where I live. It works very well indeed.

 

nat8808

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Internet the way to go , sound quality is excellent these days ...... can be a distraction at roundabouts though, damn that Guess the album cover..
And is probably technically a better audio quality (FM going through 13 bit encoders etc as they always have done - doubt it's changed).

 
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stereo70

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I have only found a handfull of decent internet stations and even then they only broadcast at 320kbs in MP3.

 

nat8808

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You say "only" but FM cuts off 15KHz because of how it is modulated before transmission. And the processing for the transmission is almost always digital at a 13 bit bitrate. So essentially, FM is only 13bit/32KHz max itself.

While 320kbps MP3 is still lossy compression, it has other factors going for it like going to 20kHz which brings certain SQ improvements and some people wouldn't reliable hear a difference between 320kbps MP3 and CD anyway. I've never tested myself.

So the whole thing of internet radio (the good quality broadcasts) v FM is probably going to be more effected by your choice of equipment. Maybe I'll have both iplayer and FM running tomorrow night and flick between them..

 

SergeAuckland

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You say "only" but FM cuts off 15KHz because of how it is modulated before transmission. And the processing for the transmission is almost always digital at a 13 bit bitrate. So essentially, FM is only 13bit/32KHz max itself.While 320kbps MP3 is still lossy compression, it has other factors going for it like going to 20kHz which brings certain SQ improvements and some people wouldn't reliable hear a difference between 320kbps MP3 and CD anyway. I've never tested myself.

So the whole thing of internet radio (the good quality broadcasts) v FM is probably going to be more effected by your choice of equipment. Maybe I'll have both iplayer and FM running tomorrow night and flick between them..
If switching between off-air and on-line, firstly there may be a level difference, but that apart, the two platforms have completely different processing applied. It's not unlike the difference between differently mastered CDs, there will be differences that have nothing to do with the medium, but the way the processors are set. The closest is probably BBC Radio 3 in the evening as although both feeds are Optimod processed, the processing is just protection limiting, so doesn't alter the sound. In daytime, there may be some light processing applied, depending on the BBC's policy, which seems to change from time to time.

BBC Radio 2 has about the best applied processing for any music station, Radio 1 is too aggressive for my liking, but suits their target audience.

S

 

avinunca1

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I've never looked back since moving from FM tuner to SBT and have found a wealth of stations out there on t'internet - certainly many more than on FM and lots without those horrible adverts or even DJ talk.

Love the BBC iPlayer too. Paul Smith and Johnny Walker any time I want to listen.

 

SergeAuckland

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I've never looked back since moving from FM tuner to SBT and have found a wealth of stations out there on t'internet - certainly many more than on FM and lots without those horrible adverts or even DJ talk.Love the BBC iPlayer too. Paul Smith and Johnny Walker any time I want to listen.
I agree, hardly use my FM tuner now that I can get iPlayer on the SBT.

S

 

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