Gobi rack -- XM/GPS antenna -- need advice

[GeorgeSSSS]

I may be wrong on some of this, but I need some advice/opinions. I have an 05 H2.

My understanding is that the little stubbie antenna at the left front of the truck handles XM and GPS. The person who installed my GOBI stealth rack positioned it so that the stubbie antenna is behind and under the front wind faring and the rack has a horizontal support directly above the antenna. GPS works perfectly all the time. XM loses signal sometimes when we are next to a tall building or tree -- -- that never happened before. Onstar & cell phone seems OK, but I haven't done much with those circuits yet.

Question: Is the rack positioned too far forward? The installer is a local body shop who is a good guy and he'll make whatever adjustments I request.

BTW: Thanks to everyone who recommended the GOBI stealth rack. It is an outstanding piece of gear.

Thanks,

George SSSS

[GeorgeSSSS]

I may be wrong on some of this, but I need some advice/opinions. I have an 05 H2.

My understanding is that the little stubbie antenna at the left front of the truck handles XM and GPS. The person who installed my GOBI stealth rack positioned it so that the stubbie antenna is behind and under the front wind faring and the rack has a horizontal support directly above the antenna. GPS works perfectly all the time. XM loses signal sometimes when we are next to a tall building or tree -- -- that never happened before. Onstar & cell phone seems OK, but I haven't done much with those circuits yet.

Question: Is the rack positioned too far forward? The installer is a local body shop who is a good guy and he'll make whatever adjustments I request.

BTW: Thanks to everyone who recommended the GOBI stealth rack. It is an outstanding piece of gear.

Thanks,

George SSSS

[HGW]

George--shipbldr has the same loss of XM with the GOBI---maybe you should PM him. I did not look at it when I had his H2.

[rodster]

George,

Based on your description, it seems your installer did a good job of positioning the rack. If you slide the rack aft to position the fairing behind the antenna base, the light bar will obstruct your sunroof by a good three or four inches. Any further forward and the aft end of the rack's sunroof opening will obstruct.

I installed my rack shortly after getting the truck and I don't remember what XM performance was like then. I know that when I'm near large power lines XM fades. I'd never considered that the Gobi fairing is blocking enough signal to cause XM to fade when it might not normally do so but your suspicion does make sense.

I've considered removing the fairing for re-powder coating. If that happens, I'll be sure and experiment with the XM signal and report back.

Rod

[shipbldr]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HummersGoneWild:
George--shipbldr has the same loss of XM with the GOBI---maybe you should PM him. I did not look at it when I had his H2. </div></BLOCKQUOTE>

Still having the same problem.

Been too overloaded with other stuff to care. I will resolve it though... and report back with an answer...

Charles

[HUMMERcustoms.com/TAZ]

I think the GPS is in the onstar box up under the dash. that is why some fo the stuff works.
I have not had problems with rakcs but, I just built one of light bars that will be up by the ant. in the front so i may develope trouble.

TAZ

[timgco]

Hey George, I have a couple of questions for you.
1: Did your installer possibly bend or hit that antenna when doing the install?

2: Does the fairing have the GPS/ XM Antenna cutout? There arer two style fairings (one with a cutout for 05/06 models and one without the cutout for 03/04).

I have experimented with this and have found that witout the rack on, if I moved the antenna base back and forth, I get interupted reception. I than took a teflon coated cooking pan and placed it over the antenna and still got reception without interuption. I have talked with a couple of people about this issue and have found the XM receiver to have issues in both cases. I am not saying this is your case, but I would check into that also.

[GeorgeSSSS]

Thanks for the comments. Here's what I can add to the data base:

For the 3 months I had the H2 before installing the Gobi Rack, XM reception was perfect everywhere -- -- it never faded; not once, not ever. Now, it goes "in and out" regularly. Sometimes, it goes totally dead. This takes place on roads where it was formerly perfect. Also, it always cuts out in the same places on the various roads near my home.

Tim: I'm not visualizing your description of moving the XM antenna base back and forth. How did you do it?

Thanks guys. We'll get it cured.

Best regards,

George

[rodster]

George -- I remember recently when you asked about XM reception with Gobi and I remember answering that I had no problem. At that time it didn't occur to me that reception fade was related to the rack. I feel I owe you an apology for not thinking this through more thoroughly. I'm sorry, George.

I searched the forum for " Gobi XM " and found a few threads of interest. This is apparently not a new problem and based on what I read, the fairing is the most likely culprit.

I'll remove mine tomorrow and take it for a test drive.

[rodster]

Well maybe it wasn't you that asked the question, George. I found the thread I was thinking of and the question was posted by someone else.

Regardless, I'm still sorry -- a sorry sack of middle-age bad memory!

Check out this thread.

I'll report back tomorrow after the fairing-less test drive.

[GeorgeSSSS]

Guys: Thanks a million. Your posts spurred me to sit up on the rack and take a GOOD look. The faring and horizontal support covering the antenna are thick plastic (insulation, I believe). The antenna is also blocked from the sky at various angles by the heavy bars of the rack and the PIAA lights. It's a miracle we are getting any sound at all.

I came to the conclusion that relocating the antenna ahead of the faring is the answer. The thread Rodster referred me to definitely confirmed my thinking. I'm going to leave the old antenna in place because it seals up the roof. My installer is a body shop that does insurance repair work. I'll ask him to order another OEM Onstar antenna and locate it ahead of the faring.

All things considered, I'm happy with the GOBI rack. It is very strong. I was out driving at 75 mph today with no appreciable wind noise. Installing a new XM antenna ahead of the faring is just a cost of the overall rack/lights project.

I'll put up a post with the results from the new antenna installation for anyone who is interestes.

Thanks again for helping me get to the bottom of this. No doubt about it. This is the best source of H2 information.

George SSSS

[4churchill]

let me know how it works out, i just realized i have my fairing installed behind the antenna and it will be blocking where my lights fit...stupid me

[rodster]

This morning I removed the Gobi fairing then went for a drive through two areas where XM always cuts out.

Good news: With the fairing off there was zero XM signal loss. While in the known bad areas, I pointed the nose of the truck in every direction to see if the rack itself or any part of it would interfere. Again, zero signal loss.

I then took the truck on the highway at speeds up to 70. IMO, without the fairing there is no discernable difference in noise level.

Best of all (and I reserve the right to change my mind on this), with the factory wind deflector installed and the Gobi fairing off, the truck looks better.

The XM antenna is situated fully in front of the rack with the tip slightly touching the rack.

[GeorgeSSSS]

Rodster: Very very interesting. I was going to put an antenna ahead of the faring, but I think I might like your idea better. At it's definitely cheaper and more simple. Thanks for the info.

I think I'm going to cut off some of the faring on the left side to expose the XM antenna and relocate the horizontal support from that side. If there is no wind wistle at 75 mph, that will be my solution. I'll post a report when I get it done.

Best regards,

George SSSS