Hooking up an unused OnStar Antenna to Sprint U720 Device...

joelkirzner · EVDO Fledgling Joined: 11 Dec 2006 Posts: 12

Can anyone help me on this...

I just purchased a 2002 Chevy Impala that has the OnStar system built in. The service is disconnected, but there is an external antenna sticking out the back window.

Could I somehow hack the wire that comes into the car from that antenna and hook it up to the external antenna jack on the U720?

Are there adapter cables I can pick up at like Radio Shack to create the correct male/female end piece to hook into the U720?

Would this increase my reception at all?

Would I better off just buying a specialized external antenna for the Sprint device and use that instead, since the hole in the glass is already there?

Thanks!
Joel

preppykid · EVDO User Joined: 06 Apr 2008 Posts: 81

joelkirzner · EVDO Fledgling Joined: 11 Dec 2006 Posts: 12

You know, I don't even know how these external antennas through the glass window even work.

Is there an actual hole in the glass, or does it pass the signal through glass wirelessly?

Now, do you think that the antenna portion is "tuned" into a specfic frequency then?

Thanks,
Joel

preppykid · EVDO User Joined: 06 Apr 2008 Posts: 81

rickey318 · Posted: Mon May 12, 2008 4:54 pm Post subject:

This was a question that was made easy. There is noway to make a onstar antenna work with EVDO or WiFi without knowing how to change the frequency and get this to plug into your EVDO Card. If you do found a way please let me know. That way you can have an great Antenna for surfing on the go!!! Very Happy

joelkirzner · EVDO Fledgling Joined: 11 Dec 2006 Posts: 12

Hahaha! That's awesome. That just made my day. Don't knock the Taurus... remember, they discontinued them and then reinstated them as the ford taurus X!

Thanks for your help!

theguero · Posted: Mon May 12, 2008 5:36 pm Post subject:

I will answer a couple of questions here.

First, the way glass mount antennas work is through capacitive coupling. A tuned piece of metal on each side of the glass tuned to the frequency and the glass acts as the dielectric. It works very well.

Now in 2002 OnStar was 800 MHz analog only. So you will not have luck using that antenna for your EVDO.

I bought the tri mode antenna that GM starting using on 2005 model vehicles to install on my Ford Escape. It has GPS, XM, and Cell / PCS (800 MHZ / 1900 MHZ). It works... But as a cell antenna, the glass mount Andrew antenna I bought kicks its ass. So I am only using the GPS and XM portion of the OnStar antenna. The antenna is made by a company call RecepTec http://www.lairdtech.com/pages/products/RecepTec-Cell-Phone.asp.

So if you are looking for a good mobile antenna, go with a good dual band glass mount.
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joelkirzner · EVDO Fledgling Joined: 11 Dec 2006 Posts: 12

Thanks!

That helps a bunch!

Joel

cherokee · EVDO User Joined: 23 Mar 2006 Posts: 59

How hard was it to hook into the antenna's? I have a 08 chevy and do not care about the free onstar I have for a year I would rather use there antenna for my evdo and gps. Do I just need a special connecter or do I have to splice in? Thanks for your help.

Jeff
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Peace

Jeff

theguero · Posted: Thu May 15, 2008 7:13 pm Post subject:

These antennas have either 2 or 3 SMB connectors (depending if the car has XM).

I had custom coax cables made at Pasternack Enterprises with SMB connectors on each end. If you want to know what an SMB connector looks like, it is just like the ones that XM and Sirius tuners use. They usually have a colored plastic housing around the connector so they will lock in place. You don't have to use the plastic housing. The acutual connector is just the metal part inside.

I may have a picture if I can find it... Let me look through my old backup hard drive.
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cherokee · EVDO User Joined: 23 Mar 2006 Posts: 59

No xm here. are the connector's by the antenna or where ever the onstar box is? If by the box I will have to find out where they are on the hhr.
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Peace

Jeff

theguero · Posted: Thu May 15, 2008 9:42 pm Post subject:

There is a blue and purple connector on your antenna. The blue is GPS and the purple is the cell/pcs.

These connections are pigtails on the bottom of the antenna.

Now I would highly recommend a good glass mount antenna for your EVDO. That antenna is more for looks and not so much for good performance.

Plus I don't know if you have Verizon Wireless. If you do, I would recommend activating that OnStar as a phone line for $10. It is a hell of a nice hands free phone.
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