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It took me six months to notice..

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When I was parking when returning to the office from getting lunch, I just noticed for the first time today that there is no extrinsic radio antenna. No rat-tail, stub, or shark-fin. It took me momentarily aback that I'd just assumed one was there this whole time. I've a whole new appreciation for the clean lines of the Tesla.
 
And no good radio reception that comes with no antenna ... there's a reason why those things still exist ... the length is specific to the waves it's gathering ... you can get by with a different type of antenna like a shorty or an embedded one but you give up on reception by doing so ..

Not that it matters, I don't even know how FM/AM is still a thing.

GPS is a different technology requiring a different type of antenna. Same basic type as XM.
 
sharkfins can be designed to cover all RF protocols.

one that I'm aware of supports 2 cables for LTE, one for wifi and one for gps. BT is not on the sharkfin, but could be (seems pointless as you need PEPs for beaconing/location stuff).

glad that the m3 doesn't have the ugly sharkfin, but then again, the choices they made were more cosmetic and they did sacrifice reception quality. I often can't get lte to my car when I'm parked (not underground but in a garage that is shared for the apartment complex, not gated and has large window openings). if we did have a proper lte antenna that was centrally roof mounted (giving an ideal ground plane) then we'd have an easier time using the mobile app and turning on the car in the AM, when its cold..

more than half of the time I try to ping my car using the app, it won't get there. could be server issues but likely its lte on my car that is spotty.

while driving, its usually ok, but the point is, the tesla design is a cosmetic compromise. we win on looks but we do suffer a bit on reception, overall. physics is physics, even for elon.
 
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And no good radio reception that comes with no antenna ... there's a reason why those things still exist ... the length is specific to the waves it's gathering ... you can get by with a different type of antenna like a shorty or an embedded one but you give up on reception by doing so ..

Exactly. For best fm reception, i.e., to capture the maximum wave length, one needs an external antenna 30"+ in length.
 
there are so many antenna configs. 1/4 wave, half wave, 5/8 wave, gain configs (yagi, dish), beam form arrays, the list goes on and on.

there are many ways to solve radio reception. the ground plane matters a lot, though, in every single config I'm aware of. glass based antennas don't have great ground planes, though. they do have good electrical length on their side, but they are not as omni directional as, say, a roof mounted antenna would be.

no free lunch; everything is a compromise.
 
Antenna engineering is one of the great black arts of engineering. I have much respect for anyone who goes into that field given how insanely complicated it is. I mean, just look at this antenna NASA used for one of its spacecraft:

NASA - Evolutionary Antenna

It was designed using evolutionary algorithms and it came up with an optimal design that no sane human would ever come up with on their own... Like I said, black art...
 
I'm not sure what you mean by that.

but the purpose of the shark fin is to enclose as many antenna elements (for the various radios) in one 'box' and run one cable, with all the little coax's in one sheath.

car companies can design their own or outsource it.

quality varies.
exactly what it sounds like - if you design your antenna correctly you don't need the fin because it doesn't need to be outside the car or up on the roof any more than it needs to be a long chrome rod poking out of the fender like it used to be years ago.
Correction - it does need to be that way for dinosaur car companies, but not for modern cars.
 
'modern cars' all need quite a number of different rf receivers on board.

gps is never a 'long antenna', and neither is 5.8ghz wifi. 2.4ghz bt and wifi are arguably 'long antennas' but still nothing like FM broadcast band. and cellular for 4g and below is also ghz-class and not mhz-class, so those antennas won't need to be large.

again, you can place most, if not all, of that in a sharkfin and having it on the glass (like FM) would offer no benefit and only negatives.
 
a properly designed antenna doesn't need a shark fin.
Other companies use them because they only ever tack on other manufacturers stuff.
Tesla just built one that works in the car.
With all due respect, are you an RF engineer?

I mean, Tesla seems to have built one that works okay in the car, but does it work better than ones contained within the shark fin? Sure, it may be "good enough," but that doesn't mean it's the best or even as good as a shark fin antenna.

As I said in an earlier post, RF/antenna engineering is a ridiculously complicated black art. @linux-works at least seems to have some familiarity with the subject (can't tell if he's an engineer or just an enthusiast) and offered some data points explaining the pros and cons of the various designs.