sullii94 Posted December 2, 2014 Report Share Posted December 2, 2014 Does anyone know of a stubby ariel that you can actually get a decent signal with? And where's the best place to buy it?Also, are the ariels the same for the lupo & arosa?Thanks Quote Link to comment Share on other sites More sharing options...
Skezza Posted December 2, 2014 Report Share Posted December 2, 2014 (edited) Does anyone know of a stubby ariel that you can actually get a decent signal with? And where's the best place to buy it?Also, are the ariels the same for the lupo & arosa?ThanksAM or FM? Sorry sullii, but you need a quick physics lesson. Lupo antenna's are 16 inches roughly, so 41cm. The reason for this is because the aerial around the car will have been measured and then the extension calculated to find the correct proportional length. So say if we remove our antenna altogether, we're potentially proportional?FM is straightforward enough. The UK runs on the 88mhz - 108mhz bands, which means the optimum length of a 5/8 wave antenna using a 300 ohm single lead (which is what you'll find in a Lupo I'm guesing) is L = 300/f * 5/8. Where f is the frequency. Typically, f used in the equation will be the middle band, so call it 98MHz. 300/98 * 0.625 = 1.91 metres, or 191 centimetres, very rough working out.So the optimal FM aerial for your car is 191 centimetres, or nearer 191.3 centimetres.. oh dear, that's still a little bit long isn't it? We don't know how long the cable is inside our roof, but if we assume it's potentially proportional (although maybe not, we don't know yet), we can't just reduce the size of our extension, we should continue to do this proportionally to the optimal size, so let's start our reduction process, 1/2, 1/3, 1/4, etc etc until we find a size that is acceptable. 1/4 is 47cm, which is probably too long, so they think "let's take it down by a 5th". That's about 38.26cm or perhaps more when the measurements are more accurate. This may have been the base that they started at size wise.Let's look at medium wave, now that's a lot more complicated. MW is inversely proportional, so reducing the length of the aerial will always negatively impact MW and this is why:Call 1000kHz our middle and using our formula300 / 1 * 0.625 = 187.5 metres in lengthNobody has a car big enough for a 187 metre MW antenna. The easy way of getting round this is using a loop. You could theoretically lose your antenna altogether by running an aerial cable repeatedly round the roof. This would work yes. However, note that the frequency band is so wide than an optimal antenna is almost pointless because it would cover about 3% of the spectrum. I imagine they base their MW antenna on the closest FM antenna. So, in reality, while we don't know for sure, it's probable that they calculated 41cm because the cable in the car wasn't proportional (potentially L - x difference in cm's) so 41cm aerial makes up the difference to make a proportional FM antenna which is proportional to the middle band. For this, they may have also added a few mm either end to make up the difference in the spectrum for MW, however the reality is that MW will always suck signal wise in a car. As soon as you go under trees, it turns to ****. Standard unless you get a 187 metre aerial Anyway, long story short, if you use a stubby aerial, you WILL negatively effect your reception. Whether that is noticeable on your radio depends on where you live etc... Edited December 2, 2014 by Skezza Quote Link to comment Share on other sites More sharing options...
lupogtiboy Posted December 2, 2014 Report Share Posted December 2, 2014 Wow! What a great explanation!I do agree with you, as I fitted a stubby antenna on my Up! which should be a longer one, and I can hardly pick up stations, even if I'm practically next to one! Quote Link to comment Share on other sites More sharing options...
Skezza Posted December 2, 2014 Report Share Posted December 2, 2014 Wow! What a great explanation!I do agree with you, as I fitted a stubby antenna on my Up! which should be a longer one, and I can hardly pick up stations, even if I'm practically next to one!I'm surprised VW don't wrap the aerial round the roof in the Up! They do in the Golf and Passat don't they? It's the best way of getting perfect reception. Quote Link to comment Share on other sites More sharing options...
lupogtiboy Posted December 2, 2014 Report Share Posted December 2, 2014 The newer (2014 onwards) models come with a different aerial base to compensate for the stubby rod. The newest Ups have DAB too!They use the Diversity aerials in a lot of there models with aerial boosters hidden in the c-pillar trims or bootlid. My dad's Scirocco aerial is in the rear screen and the shark fin on the roof is fake! Quote Link to comment Share on other sites More sharing options...
sullii94 Posted December 2, 2014 Author Report Share Posted December 2, 2014 Too late on a night to be doing physics! Ha! Thanks for the explanation though, I didn't know how it worked! So basically I would need an ariel that's proportional to the 'optimal' length for FM radio?And just basically forget about AM as I won't get signal? The ariel is actually a present for my brother, as he is getting either a lupo/arosa soon, so wondered which one to get! I have digital radio in my car so it's okay!Apparently Honda S2000 ones fit? Quote Link to comment Share on other sites More sharing options...
Skezza Posted December 3, 2014 Report Share Posted December 3, 2014 Too late on a night to be doing physics! Ha! Thanks for the explanation though, I didn't know how it worked!So basically I would need an ariel that's proportional to the 'optimal' length for FM radio?And just basically forget about AM as I won't get signal?The ariel is actually a present for my brother, as he is getting either a lupo/arosa soon, so wondered which one to get! I have digital radio in my car so it's okay!Apparently Honda S2000 ones fit?Yes, you would need one that's proportional to the optimal band of FM really, which is 98Mhz as it's the middle band (you want equal quality either side right? not one side worse, one side less). The problem is finding one my friend. You'll find it nigh impossible. In reality, while the science behind it is all good, there are probably environmental factors as well mate. I know someone on here who's had an aerial base on a Lupo corrode and cause him to get no signal at all. No amount of science will fix that, beyond replacing the actual base.You could try one of the aerial conversions, like what Mike used to sell. I think they come off a Golf MK5 and are a sharkfin. They seemed to work better than some of the stubbies do. Alternatively, just chance a stubby. Worst case, you lose a bit of signal, but it will depend on your area I'd say. They do look kind of cool, I just listen to MW and I can't live without it Quote Link to comment Share on other sites More sharing options...
lupogtiboy Posted December 3, 2014 Report Share Posted December 3, 2014 VW do a stubby one for the current shape Polo that fits6R0 035 849 D - £16.75 inc vat Quote Link to comment Share on other sites More sharing options...
sullii94 Posted December 3, 2014 Author Report Share Posted December 3, 2014 Okay thanks! Think I might chance it with a stubby one! If its crap I'll steal it for my car haha! Hmm shark fin sounds good, might have a look at one for my car(don't get exited, it's french ?)Either way I'll let you know which I get, and how the signal is affected! Does the polo one just screw straight in where the arosa one was? Quote Link to comment Share on other sites More sharing options...
Silver! Posted December 3, 2014 Report Share Posted December 3, 2014 I have a 9n stubby on my GTI. Straight fit. Quote Link to comment Share on other sites More sharing options...
666DUB Posted December 4, 2014 Report Share Posted December 4, 2014 I have a new shape Kia Picanto aerial on mine, perfect fit, perfect reception, looks great due to the screw effect. £13.00 inc vat from Kia dealers. Quote Link to comment Share on other sites More sharing options...
Skezza Posted December 4, 2014 Report Share Posted December 4, 2014 I have a new shape Kia Picanto aerial on mine, perfect fit, perfect reception, looks great due to the screw effect. £13.00 inc vat from Kia dealers. you got a photo pal? Quote Link to comment Share on other sites More sharing options...
Silver! Posted December 4, 2014 Report Share Posted December 4, 2014 Does that mean I would have to walk into a Kia dealer? Quote Link to comment Share on other sites More sharing options...
sullii94 Posted December 4, 2014 Author Report Share Posted December 4, 2014 (edited) VW do a stubby one for the current shape Polo that fits6R0 035 849 D - £16.75 inc vatGoing to get this one, found one on ebay for £14.99Will let you all know how it goes etc Edited December 4, 2014 by sullii94 Quote Link to comment Share on other sites More sharing options...
Skezza Posted December 4, 2014 Report Share Posted December 4, 2014 Does that mean I would have to walk into a Kia dealer? Don't be snobby Ray!! Quote Link to comment Share on other sites More sharing options...
Silver! Posted December 4, 2014 Report Share Posted December 4, 2014 Ki-or-a...I'll be your dog! Quote Link to comment Share on other sites More sharing options...
666DUB Posted December 5, 2014 Report Share Posted December 5, 2014 you got a photo pal? I would like to post a photo of the aerial, and of my Lupo as well, I've tried but am a bit fik with computers. But take it from me it looks great, and a bit different from the norm. Quote Link to comment Share on other sites More sharing options...
666DUB Posted December 5, 2014 Report Share Posted December 5, 2014 Does that mean I would have to walk into a Kia dealer? Fraid so, but its not to bad. Quote Link to comment Share on other sites More sharing options...
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