: *Antenna Coversion Kit for the 2004 "V"..



austin
02-12-06, 10:02 PM
Hi,

Wouldn't it would be nice not having to deal with that 1980's cellphone antenna on the rear window of the 2004 "V"... That is, of course, if your not fond of it.

I would think this is just a matter of getting the 2005/2006 antenna and doing a little splicing or adapting to the OnStar and XM boxes.

Has anyone looked into doing this?

wildwhl
02-12-06, 10:08 PM
Might try a search. There was some research done but I don't recall the results.

ctsvett
02-12-06, 11:33 PM
I looked into it once... Few problems:

1. The 05 antenna is actually Smaller and therefore, unless you do it early in the life of the car, there may be visible discoloration of the paint (since the part under the 04 will be out of the sun).
2. You need to make a jumper cable from the current 04 location to the roof (I didnt look enough to find these connectors)
3. I dont subscribe to onstar, so I removed the antenna and stopped trying to do this..

Reed

wildwhl
02-13-06, 12:30 AM
cancelled Onstar and XM...so which ant. should I remove (both - not possible) but the on glass shorty ant. is history - anyone want it?

WW

tedcmiller
02-13-06, 08:16 AM
The part of the later model combined OnStar and XM radio antenna that is used for OnStar cellular is designed for the digital-only cellular transceiver. The early model antenna is for the analog-only cellular transceiver. In addition to the footprint problems described above, there might be an impedance mismatch between the old analog transceiver and the new digital antenna that could cause degraded performance on cellular.

In Feb. of 2008, the FCC will no longer require carriers to continued to support their existing analog cellular service. The carriers will drop analog service like a hot potato. All analog-only tranceivers, like those in 2004 and early 2005 CTS-Vs, will turn into useless pumpkins. GM offers an upgrade to digital for $300 or a 3-year contract. The creator of this thread has elected to solve his problem by cancelling OnStar. Anyone wanting to get rid of the analog antenna on the back window, but continue the in-car cell phone service, should investigate the upgrade. I, personnally, have no problem with the analog antenna and have not looked at the upgrade, so I don't know if the upgrade replaces the analog antenna or simply matches to it. Obviously, if the upgrade continues to use the old antenna, those who don't like its appearance will not have their problem solved by the upgrade. However, the upgrade does eliminate the possibility of your in-car cell phone turning into a pumpkin in Feb. 2008.

ssmith100
02-13-06, 08:39 AM
You can remove the outside part of the antenna on the rear glass and Onstar will still work fine. I did this for about a month. I nicked part of the glass while removing late one evening:alchi: and with my windows tinted so dark I decided to put it back on. My mast is only about 2 inches long though. I actually kinda like it.

Shane

austin
02-13-06, 09:05 AM
>GM offers an upgrade to digital for $300 or a 3-year contract.

Found this for the Escalade, it mentions a replacement mast, not a complete antenna though, i'm sure their is a way to get the factory 2005 one to work after the digital OnStar box is installed..

http://www.truckforums.com/m_529/mpage_1/tm.htm#535

Geno
02-13-06, 11:41 AM
The part of the later model combined OnStar and XM radio antenna that is used for OnStar cellular is designed for the digital-only cellular transceiver. The early model antenna is for the analog-only cellular transceiver. In addition to the footprint problems described above, there might be an impedance mismatch between the old analog transceiver and the new digital antenna that could cause degraded performance on cellular.

In Feb. of 2008, the FCC will no longer require carriers to continued to support their existing analog cellular service. Obviously, if the upgrade continues to use the old antenna, those who don't like its appearance will not have their problem solved by the upgrade. However, the upgrade does eliminate the possibility of your in-car cell phone turning into a pumpkin in Feb. 2008.

I went so far as to get all the technical documentation and had the dealer order a kit. I did not do the conversion in the end because the digital cell still uses a rear window antenna, though it is changed out with another. I wanted the single roof mount antenna but that is not an option with the conversion kit.:mad:

ctsvett
02-13-06, 02:03 PM
Just to clarify (and back geno)...

WHen they do the conversion (if you pay for 3 years), they WILL NOT give you the combined antenna. They will just change the antenna to a shorter antenna.

The 05 does not automatically have the digital setup and the combined antenna WILL work with the "analog" onstar...

Reed

austin
02-13-06, 02:32 PM
>the combined antenna WILL work with the "analog" onstar...

As a plug in out of the box or modified?

tedcmiller
02-15-06, 07:51 AM
The analog cell phone will "work" up to a point with the new digital antenna (roof mount or a shorter glass mount) or no external antenna antenna at all. However, performance will be significantly degraded in every case with the worst case being no external antenna at all. Maximum efficiency when transmitting (and receiving to a lesser extent) at microwave frequencies is highly dependent on a proper impedance match between the antenna and the transceiver. The impedance of the antenna is dependent on the length of the antenna, the inductance of any loading coils used in the circuit, the ground plane provided by the vehicle, and the surrounding environment. The length factor is the reason for the digital antenna being shorter than the analog antenna. For maximum efficiency (i.e., lowest SWR possible) the antenna length should be an integral fraction (1/2, 1/4, 1/8, etc.) of the wavelength of the signal. Digital cell phone service operates at a higher frequency, has a shorter wavelength, and, therefore, works best with a shorter antenna than analog.

Years ago, transmitter output circuits could be destroyed by excessively high SWRs (e.g., trying to transmit with no antenna connected). Most modern transmitter circuits have protection built in to prevent this. So, while you will not ruin your cell phone transceiver by operating it with the wrong (or no) antenna, its performance will definitely be impacted.