final verdict on sharkfin reception?

I live in OC Ca. and work in L.A. I have the fin on my 06 pkg 3 There is a small signal loss, however it is marginal at best. I LOVE my fin and it looks great. Is it as good as factory???? no

 

I've had mine on for about a week now, and so far I have had no reception issues. I think once it may have momentarily dropped one radio station, but I'm not sure.

So I'll have to say overall there is no difference in reception...

 

<div class='quotetop'>QUOTE(bagwell @ May 3 2006, 01:28 PM) [snapback]249127[/snapback]</div>

Blue fins on silver cars are very IN this year...

 

I finally got mine installed last night....NO loss in reception that I could notice, either AM or FM, at least on stations I normally listen to. I really expected some loss, after so much negative comment by some. I commute over the 210 Fwy thru Pasadena (CA) over a couple of reasonable mountain passes. I got the same amount of breakup as before, and not enough to be objectionable. I'm not a big radio listener, mostly iPod and CD books on my commute.

I got the fin mostly for looking "cool" and, because my car sits outside and it makes the car cover easier to install. I had to buy a "Custom" cover with antenna pocket before I found the Fin. I will try to cut the cover down to a reasonable level (on the antenna pocket); it looks kind of dorky now.

The hardest part was reaching across the roof and getting the little screw started. I didn't make a big deal of aligning it with masking tape, etc., just quickly checked that the rear was parallel with the rear hatch opening, and slapped it down.

Anyway "Thumbs up" on reception, at least for me!

 

Also finally recieved mine, and it was very easy to install. As for reception, in LA and the Valley, there's little to no signal loss. When I was driving to visit the folks in Ventura County, there was moderate signal loss, but most of the Ventura County stations came in. Definitely worth it if you drive/live in a metro area.

 

I sold my fin...

 

<div class='quotetop'>QUOTE(mikepaul @ Jul 18 2006, 05:48 PM) [snapback]288454[/snapback]</div>

I tore mine off after a day, the reception was so poor. Needless to say, I was disappointed, because I hate the stock whip antenna.

So I started researching other antenna options on-line. I came to the conclusion that there wasn't anything out there that I really liked. So I started researching antenna theory with the thought of building my own. After a few days of reading I came to the conclusion that antennas are truly black-magic.

I went out to the garage and experimented with some of what I learned and accidentally hit on a configuration that at least in "driveway tests" was better than the stock whip antenna and would fit in a fin roughly half the height of the stock whip.

So I've started building an enclosure inspired by aircraft "blade" antennas. Like the shark-fin antenna it will mount over the stock base, so that the original antenna can be restored if desired. I'll share some pictures when I've completed the prototype, and have had a chance to test it while driving.

Peter.

 

If you take off the whip, where do you put your flag?

 

<div class='quotetop'>QUOTE(Alnilam @ Jul 19 2006, 09:58 AM) [snapback]288754[/snapback]</div>

Buy a cheap ($12) car cell phone antenna and mount it to your front license plate bracket. You can put your flag there (as long as it's small), plus you'll be able to know where the front of your Prius is. I know a Prius owner that did this and it works very well.

 

<div class='quotetop'>QUOTE(PriusDad @ Jul 19 2006, 11:51 AM) [snapback]288747[/snapback]</div>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
OK - - Now that you've publically commited to checking out antenna options, I WANT to hear of any favorable progress that you've made! I am really curious. Don't let us down -

I occasionally listen to weaker AM stations & would hate to loose any quality there. And I am NOT thrilled with the factory whip. It is not a pleasure to have unscrew it, every time I go throiugh the car wash!

 

<div class='quotetop'>QUOTE(Frank Phinney @ Aug 6 2006, 12:59 PM) [snapback]298700[/snapback]</div>

Will do. I made good progress this weekend... I had to make a copy of the stock antenna base because I want mine to slip over it snugly. That involved making a silicone mold and casting a duplicate part that I can modify to make room for the connector wire to the antenna.

I also vacuum formed the first prototype shell and painted it to see if I needed to work out any kinks. As it turns out, the plastic stuck to the mold and took off some of the material. So I need to fiberglass the mold to make it a bit more durable. That will take another couple of weekends to sort out, and then I'll try forming the first prototype I can stick on the car and drive around with.

I took some photos of the test fin on the car, but I have yet to download them from the camera. I'll do that tonight when I get home from work. Then I'll post them to the thread. The current shape of the fin is a bit more like an aircraft fin than a "shark" fin. It is roughly half the height of the stock whip antenna, and looks a bit like the vertical stablizer of an F-100 Super Sabre.

Peter.

 

<div class='quotetop'>QUOTE(PriusDad @ Aug 7 2006, 02:19 PM) [snapback]299253[/snapback]</div>

So it looks like most of the photos were under exposed or fuzzy... it's hard to take pictures of a black car/antenna at night with no natural light! So, here are the only two pictures that turned out, showing the first prototype of the antenna on top of our Prius:

[attachmentid=4400]

[attachmentid=4401]

I'll post more pictures after I've strengthened the molds and formed a second shell, added the antenna innards, and had a chance to drive it around to test reception a bit more.

Peter.

 

PriusDad-
Way to go! I think you might be on to something. That looks a lot better than the stock whip. Are you also testing it to see if XM reception is also better with your fin? Do you have XM? I have my XM micro-receiver under the shark fin and did notice a reduction in reception when I am on canyon raods with large trees. Good work so far can't wait to hear the reception results. Thanks for taking the time to make a cool part for our cool cars.

 

The major problem with smaller antennas is that in general, the smaller the antenna, the weaker the received signal.. In an urban area, where signals are strong, most people would not notice any difference, however rural reception would likely take a major hit by going to a smaller antenna..

The second problem is the radome material- the radome is the enclosure of the actual antenna element, ie, the shark fin itself.. Certain plastics tend to attenuate the signal instead of looking transparent to the radio waves- any plastics containing carbon or metallic coloring agents will cause signal attenuation, the same goes with any metallic paints that go on the outside.. The paint shop should be instructed that sparkles in radome paint should be done with mica flecks instead of aluminum particles.. Mica is RF transparent, aluminum is not..

 

<div class='quotetop'>QUOTE(c4 @ Aug 8 2006, 07:27 AM) [snapback]299574[/snapback]</div>

You are correct about smaller antennas. However, the antenna housed inside my enclosure isn't shorter than the stock whip. It's quarter wavelength for the middle of the FM band, and folded in a fractal pattern. The one thing I was able to cull from all my antenna research is that fractally bending the antenna wire makes the antenna sensitive to a wider range of frequencies around it's center.

I experimented with five different folding patterns in all. In one I made an error, and it wasn't actually fractal, and the reception was worse than the stock whip. Three of them were about the same as the stock antenna, and one was slightly better. Obviously, I intend to use the fold that turned out slightly better.

Regarding metallic paint, I've always wondered about whether it would interfere with reception or not. Glad to see someone else was thinking the same thing. As it turns out however, my VG shark fin was painted (non-metallic) black, and the plastic seems to be thick Styrene or ABS, which isn't a high-carbon content plastic. So I think the reduction in reception I experienced was clearly due to the size and orientation of the antenna elements within the shark fin. The current prototype I'm making is made from acrylic (because it is readily available, and easy to work with), and I will need to see how it impacts reception. Acrylic is also a bit brittle, and the ideal plastic in terms of toughness would be polycarbonate, but as you point out (and its name implies), it is a high carbon content plastic. Consequently, I too may move to something else like ABS.

In any case, I keep you posted as testing progresses.

In response to cairo94507, I have to ask: is your sharkfin painted with a metallic paint? Also, looking at the location of the anntena elements in the VG sharkfin, I could imagine that they would block some of your XM signal, as one element would be above and to the right of XM antenna, and the other immediately behind it. The result would be at least partial obstruction of the FM signal from at least two sides. In contrast, I could in theory make place for the XM antenna in the lower base just in front of the actual fin where my antenna element is housed, thereby giving it a clear view to the sky. However, since I don't have an XM antenna, I can't say whether it will actually fit there or not. Having seen two types of XM antenna, I would say that only the smaller style stands a chance of fitting in my current shell.

Peter.

Peter.

 

<div class='quotetop'>QUOTE(PriusDad @ Jul 19 2006, 12:51 PM) [snapback]288747[/snapback]</div>

Peter, I just took mine off after a week of deparately hoping that I could find some way to live with it. :angry: All of the stations I listen to had their signal so degraded as to be useless. I live about 40 miles outside of Boston and have only had problems with the stock antenna with stations farther away like up in NH. With the shark fin antenna I couldn't even get the NH stations, and the Boston stations were very spotty. Funny that in my parking spot it was fine before I glued it down - it's only when moving that you hear the signal fade in and out, so the antenna doesn't seem to handle echoes and interference properly and doesn't give the discrimination circuitry in the radio enough to work with.

So, now how do I get off the residual glue from the gasket? Other than using my fingernails and getting a millimeter at a time, are there any better techniques? Rubbing alcohol didn't work, nor did lighter fluid or nail polish remover, though once the rest of the gasket itself is off they might get the area clean...

 

<div class='quotetop'>QUOTE(Erik Tkal @ Sep 28 2006, 01:02 PM) [snapback]325206[/snapback]</div>

For me it was a combination of Denatured Alcohol, fingernails, and a towel. Denatured Alcohol, also known as Shellac Thinner can be purchased at OSH or any major hardware store, and is fairly benign; it doesn't damage auto paint or clear coat.

The technique I used was to first peel up a millimeter or two, Next, I wrapped a towel around my index finger and wet it with the denatured alcohol. Finally, using my finger in the damp towel, I pushed this lifted edge as if to roll the remaining adhesive up like a carpet roll. You have to push with quite a bit of force. Using this approach, I could get roughly a centimeter to unroll from the top of the car before it broke off. Then I'd repeat the process.

Other than using the denatured alcohol, there wasn't any magic to it. Just a lot of elbow grease. Once I had the stuff off though, I quickly put a new coat of wax over the area, since the denatured alcohol will strip of the wax and leave the paint underneath unprotected.

Regarding the new shark-fin prototype I posted pictures of, its progress has slowed down a bit, mostly due to deadlines at work. I have formed the fin shell successfully, but need to still mount the new antenna in it, paint it, and stick it on the car for some testing.

Getting some adhesive for the new fin has also been difficult, since 3M only sells 108 yard rolls of the stuff, and that's a bit much for prototyping work. I called them about getting a sample, and the lady there took all my information, but that was almost two months ago, and I haven't received anything yet. So even when I do complete the prototype antenna housing, I'll have no way to affix it to the car. I guess I'd better get back on the horn to 3M and see what's up with my sample...

Peter.

 

I installed my SharkFin one month ago. I've noticed a slight drop in reception. I sometimes listen to WFAN (660 am) out of NYC and I can still pick it up clearly from Maryland. Most of the time I'm listening to Sirius so I installed the Fin more for the look, but the performance is still adequate.

 

<div class='quotetop'>QUOTE(PriusDad @ Sep 28 2006, 04:28 PM) [snapback]325224[/snapback]</div>

What about just using GOOGone? Works like a charm!

www.googone.com