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Oregon Series Antenna Type?


Didjerrydo
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After talking to one of Garmin's higher level outdoor tech guys yesterday and complaining about thier choice of going back to the "patch" type antenna in the Oregon's, he informed me that that was not really the case! He described the Oregon's internal antenna as being a new inovative type that he referred to as a "ceramic" antenna, that he said ran across the top of the unit and down the left of the inside of the units.

He said this was an entirely new thing for Garmin and seemed to feel that it would be almost an equal performer as a helix type. Does anybody know much about this type antenna?

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I doubt the U-shaped thing is the antenna. I would GUESS it's a grounded soft list that is pressed against the metall back of the display and thus creates a shielded box for the electronics.
If you look at more of those photos, the Nuvi has a metal plate that does exactly what you've said. So where's the antenna?

 

Here's some photos:

 

Oregon MB. The antenna has to be outside the shield.

Oregon400t_005.jpg

 

Nuvi 255 MB. I'd guess the Nuvi antenna is the little sqiggle above and left of the ST chip.

Main_board_forum.jpg

 

Notice the Nuvi shield totally surrounds the electronics, whereas the Oregon is U-shaped, why?

 

Oregon400t_004.jpg

 

From this photo, I'd say the Oregon antenna is the white object below the Garniak logo. The board is inverted so we can read the text. The purpose of the shield is to shield the antenna from the electronics.

Edited by MtnHermit
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The white thing below the Garniak logo being the antenna is my guess as well. Notice how there is a big empty space above the display in the plastic case where that white thing is located.

 

Why the U isn't a closed rectangle is a mystery though, maybe the contact to the display get squeezed to much if they put a list there, it does look as if the PCB was prepared for an (almost closed) rectangle though.

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Notice how there is a big empty space above the display in the plastic case where that white thing is located.
I did notice and it was part of my conclusion as well. Also note the small holes in the PC board at the edge. Both their being there and the irregular pattern is no accident. However, I'm clueless at what they do.

 

Why the U isn't a closed rectangle is a mystery though, maybe the contact to the display get squeezed to much if they put a list there, it does look as if the PCB was prepared for an (almost closed) rectangle though.
You clearly know your way around a PC board. I suspect that you also know that antennas are black magic. The best way to know if a design will work is to build it and test it. Clearly it works. Edited by MtnHermit
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Good information, I'll defer to you guys about the location of the antenna. I had received that same information from Garmin as the OP, that the antenna started near the top front of the unit, ran over the top of the GPS and down the back sides (I was told both sides, not just the left).

 

When I saw the "U" shaped rails running up and down the unit, especially since they had a ceramic looking texture, I assumed that this was the antenna. As you suggest it does seem that is some sort of shield.

 

GO$Rs

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Also note the small holes in the PC board at the edge. Both their being there and the irregular pattern is no accident. However, I'm clueless at what they do.

 

 

Hm, you don't think they are normal via-holes? Connecting the different copper layers in the PCB with each other. There are probably grounded plates on both sides of the PCB and the holes connects them together.

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Also note the small holes in the PC board at the edge. Both their being there and the irregular pattern is no accident. However, I'm clueless at what they do.

Hm, you don't think they are normal via-holes? Connecting the different copper layers in the PCB with each other. There are probably grounded plates on both sides of the PCB and the holes connects them together.

Sure, but that ground need could easily have been solved with one hole, their are dozens. The circuit designer intended to create a ground plain using so many holes. Why?

 

Compare the Nuvi 255's simple solution to the Oregon's sophisticated solution. My 205W works incredibly well on the carpeted floor of my truck. So why did the Oregon designers go to so much trouble?

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That was the Ah Ha I needed. That antenna is both the RF GPS receiver and also the Bluetooth GPS-to-GPS transceiver antenna. Hence the increased sophistication compared to the Nuvi. Bingo!!! :laughing:

 

Not Bluetooth (ANT) but yes that would make a lot of sense, I forgot about the ANT wireless piece.

 

GO$Rs

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Not Bluetooth (ANT) but yes that would make a lot of sense, I forgot about the ANT wireless piece.
Dollars to Donuts, it is Bluetooth. Just that Garmin doesn't want to admit it. Just think of all the trouble calls they'd get if people tried to connect wirelessly to their PCs.

 

Someone will hack it soon enough and post a thread on how to wirelessly connect via Bluetooth. :laughing:

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Not Bluetooth (ANT) but yes that would make a lot of sense, I forgot about the ANT wireless piece.
Dollars to Donuts, it is Bluetooth. Just that Garmin doesn't want to admit it. Just think of all the trouble calls they'd get if people tried to connect wirelessly to their PCs.

 

Someone will hack it soon enough and post a thread on how to wirelessly connect via Bluetooth. :laughing:

 

That would be excellent, electrically are they similar interfaces?

 

GO$Rs

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Just because that antenna type is made for Bluetooth doesn't mean that is what they are using. More than likely it's just a GPS band antenna. The white part is the antenna for sure, the silver square component with circle enclosed next to it is a test port antenna connection for service/test/alignment work.

 

Linear polarization would mean 3dB loss just from polarization mismatch over the circularly polarized helix and patch antennas. Dielectric antennas are also not known for high performance.

 

The main application for these antennas is mobile phones which have integrated GPS, because of their small size and cheap cost. Seems like a poor choice for a premium GPS navigation unit.

 

Wonder who will be first to desolder that antenna and connect a quadrifilar helix along with the necessary plastic case surgery.

Edited by Gamma68
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Not Bluetooth (ANT) but yes that would make a lot of sense, I forgot about the ANT wireless piece.
Dollars to Donuts, it is Bluetooth. Just that Garmin doesn't want to admit it. Just think of all the trouble calls they'd get if people tried to connect wirelessly to their PCs.

 

Someone will hack it soon enough and post a thread on how to wirelessly connect via Bluetooth.

That would be excellent, electrically are they similar interfaces?

I don't understand your question.

 

My Bluetooth conjecture is based on three things:

- Cost, Bluetooth components are widely available, low cost and pre-engineered.

- Range, the stated range of the wireless handshake is exactly Bluetooth

- Didjerrydo's pdf shows a combination GPS and Bluetooth antenna

 

This is simply a: If it looks like a duck, walks like a duck, . . . you know the rest.

 

Garmin has never said Bluetooth because of support, they've intentionally limited the handshake to GPS-to-GPS, not GPS to PC.

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Hmmm, now that I think of things....

 

The Forerunner 405 uses a small usb reciever to exercise info to the PC. It may be worth asking Garmin to make that avalable on the Colorado and Oregon series and make it work wtih the GPS data transer.

 

It would be nice not to have to hook up a cable to get maps, geocache information, track data etc. in and out of the units

 

And it would be one less hole in the case....

 

Hmmm time to send a note to Garmin.

 

Cheers all!!!

Edited by Branky
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Hmmm, now that I think of things....

<snip>

It may be worth asking Garmin to make that avalable on the Colorado and Oregon series and make it work wtih the GPS data transer.

 

It would be nice not to have to hook up a cable to get maps, geocache information, track data etc. in and out of the units

<snip>

Hmmm time to send a note to Garmin.

 

Cheers all!!!

I talked to the 'Garmin Team'(such as what showed up, they left the Mac guys home, in Seattle no less, what were they thinkin'?)

when they were in Seattle for the initial "Meet & Greet" at the Colorado launch. I asked this same question at that time, Their

response was to the effect; No, not going to do it, think USB 1 is slow, our implementation wasn't designed with that amount of

data through-put capability.

Not a direct quote, but that's how I interpreted the response I got.

I agree it would have been a sweet option, especially from case integrity/waterproof, and convenience standpoints, but alas, it'll

probably never happen.

 

Norm

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http://www.thisisant.com/index.php?section=24

[broadcast, Acknowledge and Burst Message

ANT allows three types of message transactions providing flexibility for different usage scenarios. When newer data is of more importance and occasional loss of a message is not critical, broadcast messaging is a reasonable choice; otherwise acknowledged messages can be used. For each ANT channel, the minimum message can be as low as 0.5Hz. For individual ANT device, the combined ANT channel message rate is around 200Hz. The third type is burst messaging which looks after the requirement of bulk data transmission and can be as fast as 20kbps of true data throughput]

 

Slower than an old-school phone modem.

 

Norm

Edited by RRLover
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