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Thread ID: 78432	2007-04-15 07:57:00	Which antenna will give me the best quality?	Ninjabear (2948)	PC World Chat

Post ID	Timestamp	Content	User
541213	2007-04-15 07:57:00	Hi There My father is sending me his Usb tv tuner overseas and all I need is to buy an antenna. I went to dicksmith today and saw a few antenna at different pricing and all sorts of style search.dse.co.nz I live directly in town so I don't think reception will be a problem but of course I want to invest on an antenna that gives me quite good picture quality. Are all indoor antenna the same even though the price is different or is there an antenna thats better than the rest?	Ninjabear (2948)
541214	2007-04-15 08:05:00	I bought the L4016 indoor one a few months ago before I hooked up a freeview box to the sky dish. The antenna worked ok and is more solid than the 1st one i got from DSE where the metal antenna bit fell off in 2 minutes... the red and green leds are really annoying.	Shortcircuit (1666)
541215	2007-04-15 08:11:00	You can't beat an outdoor aerial but otherwise just a standard pair of rabbit ears will do if your reception is pretty good in your area.	radium (8645)
541216	2007-04-15 08:50:00	I've always found that those amplified ones are generally pretty crap. I've always had better results with the rabbit ears, but in saying that an outdoor aerial would be better.	DarkCypher (11945)
541217	2007-04-15 10:12:00	PC's "radiate" quite a bit of local interference, unless you have high signal area use a proper outside antenna, making sure you get a model designed for your area. TV adapters tend to be less sensitive than TV sets, so a bit more signal is needed. Amplified indoor ones are rubbish. You cannot amplify something that is already weak and noisy without amplifying the noise as well (including interference noise coming from the PC). TV channels use different frequencies in different regions. Aerials are designed for the frequencies needed generally.	godfather (25)
541218	2007-04-15 23:04:00	Godfather; You cannot amplify something that is already weak and noisy without amplifying the noise as well (including interference noise coming from the PC). It's not often I'll disagree with you GF, but there is one common fallacy that appears to be being perpetuated here. Weak signals do not contain "noise", that is to say, they don't pick up noise along their transmission path, therefore amplifiers do not amplify noise at all unless they are cascaded. In the latter case they will amplify noise introduced by earlier amplifier stages which is why AGC (automatic gain control) is almost always applied to the first amplifier in the sequence; firstly so that it does not overload, and secondly so that it does not introduce unnecessary noise into the system by operating at full gain. Subsequent stages may also have AGC applied. Noise in TV signals can be introduced by local sources (as you correctly suggest) but in the absence of any local source, the noise seen on screen is created internally in the tuner and subsequent signal amplifiers, hence the expression "signal to noise ratio" used in equipment specs. Noise on TV screens is called "snow" and is generated inside the TV. If you unplug the antenna and short circuit the antenna socket, the on-screen noise (and noise in the sound) will continue because it is all being generated internally. That is a pretty good indicator of why weak TV signals are snowy and the sound is noisy! Back when Adam was a cowboy and Eve was still a rib, I worked with what was then (if you don't include military spec gear) pretty much state of the art VHF communications equipment for the Kapuni Gasline project and apart from the first couple of years I repaired and refurbished almost every radiotelephone used on that project through a central workshop in Auckland. Minimum signal to noise ratios of 12db at 1µV into 50 ohms were the target figure, but were often exceeded. That was a measure of the internal receiver noise in relation to a noise-free signal from a Marconi signal generator. In the field we used a different measure of "signal to noise to noise" (yes, two noises, the first was the aforementioned internal noise and the second was the environmental noise). The bottom line is this: if the signal isn't strong enough in the first place, no amount of amplification will help because each additional stage will just add more noise. The most common internally generated source is "Shot noise" which is caused by random fluctuations of the electric current in electrical conductors, which in turn are caused by the fact that the current is carried by discrete charges (electrons). This occurs not only in the p-n junctions of amplifier transistors, but also in any other conducting materials and devices along the signal path. Noise is primarily the curse of analogue systems, therefore because digital data can be recreated "clean" during processing it is a superior medium for information transmission. We won't talk about digital artifacts in sound systems though, because that is a whole new story and you usually need crystal ears to hear them in modern technology. Either that or be a magazine's Hi Fi reviewer, they can hear differences between two pieces of wire! Cheers Billy 8-{)	Billy T (70)
541219	2007-04-15 23:11:00	The bottom line is this: if the signal isn't strong enough in the first place, no amount of amplification will help because each additional stage will just add more noise. Billy 8-{) Which is exactly what I was trying to point out, however your post adds clarity to that.	godfather (25)
541220	2007-04-16 02:02:00	I've yet to see ANY of those claimed amplified signals TV antenna improves reception that is not good. You can turn the dial to any position you like, but the results will be the same.	SKT174 (1319)
541221	2007-04-16 03:04:00	Go for a great big antenna, put it as high as the law allows, use good cable and connectors. Also, make sure you get a black anodised one. The yellow ones attract programs where we lose all sorts of important sporting fixtures	R2x1 (4628)
541222	2007-04-16 05:45:00	Hi There My father is sending me his Usb tv tuner overseas and all I need is to buy an antenna. can it tune in NZ frequencies ? PC's "radiate" quite a bit of local interference, unless you have high signal area use a proper outside antenna, making sure you get a model designed for your area. yes, one thing to watch. hence outdoor aerials are oreferred. Weak signals do not contain "noise", that is to say, they don't pick up noise along their transmission path, therefore amplifiers do not amplify noise at all unless they are cascaded. In the latter case they will amplify noise introduced by earlier amplifier stages which is why AGC (automatic gain control) is almost always applied to the first amplifier in the sequence; firstly so that it does not overload, and secondly so that it does not introduce unnecessary noise into the system by operating at full gain. Subsequent stages may also have AGC applied. no offence but "noise" is often used as another term for "unwanted signals" on the same frequency. you can pick up the good as well as the bad which is why you can sometimes get less snowy pictures from a weaker signal compared to a better signal. also AGC amps are a rarity in the aerial world. you need deep pockets for those. I've yet to see ANY of those claimed amplified signals TV antenna improves reception that is not good. You can turn the dial to any position you like, but the results will be the same.totally. i've tested them before and there is no increase in signal what so ever.	tweak'e (69)
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