Digital Radio Central - Sponsored by TSS Radio
  DRC Home Page DRC Forums Contact Us  
 
SIRIUS Backstage Forum
 
 
 
  Sirius Satellite Radio XM Satellite Radio iTunes/iPod Slacker Pandora  
 
 
FAQ Members List Calendar Search Today's Posts Mark Forums Read  
Go Back   SIRIUS Backstage Forum > >
Visit Digital Radio Central

Notices

Install Garage & Help Desk You've got the radio, now which cable goes where? Got questions about factory installed radios in your car? Ask any installation or help questions here and someone will get to you soon.

 
 
Thread Tools Display Modes
 
 
Old 01-06-2007, 09:48 PM   #1
twister
Channel Surfer
 
Join Date: Jan 06, 2007
Posts: 14
twister is on a distinguished road
Default Problems w/Sirius reception in my car

My first post here, and I hope you guys can let me know if this is *typical* behavior. My setup is VaisTech SLS Sirius kit and Sirius receiver integrated with touch screen audio controls in my GS350. This year Lexus cut their ties with Sirius (very upset about that ) and they hardwired XM antenna into sharkfin, therefore I have to use external antenna (that little 1"x1" puck). Anyway, after a few trials I found I can ONLY get a reception with antenna placed OUTSIDE on the trunk (actually top of the side fender on the metal surface). BTW, I'm in Central Jersey, close to the shore half way in-between NYC and Philly (if geographic location matters in here?).

What I found is that anytime I'm under the bridge, I loose connection for a brief period. I guess this is understandable since I don't have a satellite in site? But, anytime I'm going down the road with trees along the side, connection becomes very choppy. This is a winter time, and trees are without leafs. Is this normal? What's going to happen during the summer time when trees are green? Is there a different antenna I should look into? I read from another forum someone got XM antenna from Best Buy or Circuit City and they have excellent reception. Is this possible? I thought they operate at different frequencies and optimized accordingly. From what I hear, XM has repeaters so their radio works of both satellite and terrestrial antennas and they don't have to worry about obstacles like this. How about Sirius, is it only satellite or do they have repeaters as well?

Anything you can help me with, I greatly appreciate. Cause, I’m not sure if this is a general problem with Sirius reception at this moment (I have read a few people having dropouts as well) or is this a problem with my receiver/antenna?
twister is offline  
 
 
Old 01-06-2007, 10:00 PM   #2
VDCHawk
Top Dog Member
Problems w/Sirius reception in my car
 
VDCHawk's Avatar
 
Join Date: Jan 16, 2006
Location: Parsippany, NJ
Posts: 1,374
VDCHawk will become famous soon enoughVDCHawk will become famous soon enough
Default

There have been users that used the factory XM antenna for Sirius service.

Both Sirius and XM have ground repeaters. In theory XM is MORE likely to get blocked because of the low angle of the both of the XM fixed satelllites. Because the Sirius birds move in the sky, and are at a much higher angle, they are less likely to be blocked.

Both services suffer from urban canyons. You will not be able to get satellite signal between large buildings. This is why both have ground repeaters in the urban areas.
__________________
2 SL100s, Home and Car docks
Internet stream on Samsung SCH-i760

Verizon FiOS, Fiber-Faster-Cheaper Now with TV (Multi-Room DVR rocks)
Problems w/Sirius reception in my car
See why you should be folding@home http://www.teamshort-media.com/videos/foldflash2.html
VDCHawk is offline  
 
 
Old 01-06-2007, 10:26 PM   #3
twister
Channel Surfer
 
Join Date: Jan 06, 2007
Posts: 14
twister is on a distinguished road
Default

VDCHawk, I assume up North in Parsippany you get a good reception in a car? What antenna do you use? I'm down South around Freehold area, no tall building in here, just lots of trees along the small roads.

So, do you think I can connect XM antenna (its already prewired into my factory sharkfin antenna) for Sirius connection? I also read across other forums people experiencing some reception problems in the last few weeks. Is this common?
twister is offline  
 
 
Old 01-07-2007, 12:01 AM   #4
brianrwebb
Rocket Scientist
 
brianrwebb's Avatar
 
Join Date: Jan 15, 2005
Location: So.Cal.
Posts: 984
brianrwebb is on a distinguished road
Default

Twister, you could use your OEM XM roof-mounted antenna, except that Lexus has terminated the Single Lead XM coax with a proprietary connector, making adaption via a cable adapter impractical due to the costs involved buying a compatible RF harness from Lexus, before modifying it for a Sirius tuner.

this is the OEM XM Lexus Proprietary SAT Lead termination:





if you lived here in So.CA, i could easily modify the existing SAT lead and create an extension coax for connection up front where i assume you have the Sirius tuner connected to the VAIS Tech device.

here is a picture, from an IS350 Lexus owner, who had a Mark Levison sound system, which, if you can still find it within the Lexus dealer network, is still compatible with the now dis-continued OEM Lexus Sirius Tuner, no longer manufactured, who modified his existing lead with a RA SMB for connection to that Sirius tuner:



all you really need to do is find a person with RF Connector experience who has some speacialized tooling and connectors, and your use of the XM antenna on the Sirius tuner would be possible.
__________________
Complete OEM XM Honda Tuner Locations with embedded links to HON-SC1 installations per vehicle model- PDF format:
http://www.keepandshare.com/doc/view.php?id=482275&da=y

OEM XM Acura Tuner Locations with embedded links to HON-SC1 installations:
http://www.keepandshare.com/doc/view.php?id=522731&da=y

brianrwebb@ca.rr.com
brianrwebb is offline  
 
 
Old 01-07-2007, 09:07 AM   #5
twister
Channel Surfer
 
Join Date: Jan 06, 2007
Posts: 14
twister is on a distinguished road
Default

Brian, thank you very much for your detailed reply!!!

This is a very good info. So, I assume antenna is just "an antenna" without any active filter components or anything like that since XM vs Sirius use different frequency band? Would it make more sense to just cut a piece of cable with a connector from my current Sirius antenna (that 1x1 puck), than cut off the connector from my existing built-in XM antenna and splice Sirius connector to this cable? I assume its just a regular wire with a shielding harness or something like that?
twister is offline  
 
 
Old 01-07-2007, 09:47 AM   #6
HomieG
Sirius Star
 
HomieG's Avatar
 
Join Date: Feb 06, 2006
Location: Somewhere in the USA
Posts: 1,431
HomieG is on a distinguished road
Default

Quote:
Originally Posted by twister
Brian, thank you very much for your detailed reply!!!

This is a very good info. So, I assume antenna is just "an antenna" without any active filter components or anything like that since XM vs Sirius use different frequency band? Would it make more sense to just cut a piece of cable with a connector from my current Sirius antenna (that 1x1 puck), than cut off the connector from my existing built-in XM antenna and splice Sirius connector to this cable? I assume its just a regular wire with a shielding harness or something like that?
The antennas are indeed active (have an LNA), but any sort of active filtering is the result of using a supposedly optimized-for-XM antenna, for Sirius use. XM and Sirius bands are essentially ajacent to each other. While using an XM antenna for Sirius may not, in theory, be an optimal situation, it's pretty close to that, and definitely worth a try with a factory installed situation like you have. Assuming that your XM antenna will work when powered via a Sirius radio, again, I'd definitely try it.

I would avoid splicing the coax cables. That will cause an impedance bump in the cable, and likely end up in a poorly optimized situation. Using adapter cables and the proper connectors like Brian recommends will help you avoid that, so long as the right tools are used to make proper connections.
__________________
- Homie
Lifetime Sirius Subscriber

Originally Posted by atlwxman: "I love Sirius...but in my car, not in my portfolio."

Originally Posted by Andrew-NYC: "...Just make a radio that gets both services, and there will be no need for the merger!"


Current Sirius radios:
Brix Streamer Replay
XACT "Visor"
XACT XTR8 Replay
HomieG is offline  
 
 
Old 01-07-2007, 12:28 PM   #7
twister
Channel Surfer
 
Join Date: Jan 06, 2007
Posts: 14
twister is on a distinguished road
Default

Hmm, you really think impedance mismatch (isn’t this 75 ohm coax?) will be that significant in splicing considering such a slow rate of transmission? Either way, I guess the real answer is in trial-and-error. Unfortunately, this is not in my hands. My dealership warned me that I will void my warranty if the install going to be by myself or unauthorized shop. My SLS module was put in by "their" authorized shop. All I can do is just to complain why I'm getting a choppy reception while others don't.

I'm a little concerned with that active filter. Even with adjacent band, if filter is not wide enough it will filter out the main carrier frequency, in theory.
twister is offline  
 
 
Old 01-07-2007, 04:43 PM   #8
HomieG
Sirius Star
 
HomieG's Avatar
 
Join Date: Feb 06, 2006
Location: Somewhere in the USA
Posts: 1,431
HomieG is on a distinguished road
Default

Quote:
Originally Posted by twister
Hmm, you really think impedance mismatch (isn’t this 75 ohm coax?) will be that significant in splicing considering such a slow rate of transmission? Either way, I guess the real answer is in trial-and-error. Unfortunately, this is not in my hands. My dealership warned me that I will void my warranty if the install going to be by myself or unauthorized shop. My SLS module was put in by "their" authorized shop. All I can do is just to complain why I'm getting a choppy reception while others don't.

I'm a little concerned with that active filter. Even with adjacent band, if filter is not wide enough it will filter out the main carrier frequency, in theory.
I am pretty sure that the coax is 50-ohm. The rate of transmission is not the issue. The issue is the strength of the satellite signal at the receiver input. A poor signal will cut out a lot. There is a reason that RF connectors are used. Most good ones are constant impedance such that the loss throgh them is minimied. Yes, I do think a splice without constant impedance connectors, will give you less than optimimal results. But like you said, it's worth a try.

You know, the mag-mount antennas don't look too bad on cars. I've got two high-end German cars, and have them on both. Trick on them is to keep the surfaces between the antennas and the car as clean as possible. I remove mine frequently, clean the bottom of the antenna and the area where its mounted on the car, and wax that area too. Been doing this for years with amateur radio antennas, and the cars still look fine with no paint mars under the antenna magnetic mounts. Of course if I had a car with an XM antenna in it and wanted to try it on Sirius, I'd do that first.

Keep us up to speed on what you end up doing.
__________________
- Homie
Lifetime Sirius Subscriber

Originally Posted by atlwxman: "I love Sirius...but in my car, not in my portfolio."

Originally Posted by Andrew-NYC: "...Just make a radio that gets both services, and there will be no need for the merger!"


Current Sirius radios:
Brix Streamer Replay
XACT "Visor"
XACT XTR8 Replay
HomieG is offline  
 
 
Old 03-23-2008, 06:54 PM   #9
bennybenz
Just Tuned In
 
Join Date: Oct 20, 2004
Posts: 4
bennybenz is on a distinguished road
Default

Today I took a Sirius antenna I had and cut into it. It's just coax, so I separated the signal from ground. I did the same for the Shark-fin connector in my trunk. Cut it and separated the signal wire from ground. I soldered the Sirius cable to the Shark-fin cable and even did a continuity test to make sure that I had a solid low-impedance connection. All checked out OK, but when I tried using it with my Sirius Stiletto, the reception was awful. I had maybe one bar, and the signal kept dropping out. It wasn't even very reliable in a wide-open space without any trees or buildings nearby.

If I replug in the hockey puck antenna, immediately it improves. I'm glad I didn't cough up $60 for the Vaistech adapter (http://www.vaistech.com/ecart/agora.cgi?product=10), because clearly the shark-fin antenna doesn't seem to do very well with Sirius receivers. I'd like to think I'm wrong, but I don't see what I could be doing wrong. Am I missing something?


I'm pretty disappointed by this.
bennybenz is offline  
 
 
Old 03-24-2008, 01:40 AM   #10
moolman
Just Tuned In
 
Join Date: Feb 29, 2008
Posts: 2
moolman is on a distinguished road
Default

Well, I use the Vaistech cable to attach my OEM Sirius reciever to the shark fin on my GS350 and it has improved reception. A specific spot is behind my building when I was installing the cable. I would switch back and forth and the shark fin would get no drops while the hockey puck did. At the same time, my hockey puck is next to the rearview mirror, the OEM position for the Sirius antenna.

I don't have a signal meter on my radio but if you live in Los Angeles, you can come over and plug in your radio using the vaistech cable.
moolman is offline  
 
 
Old 03-24-2008, 12:06 PM   #11
bennybenz
Just Tuned In
 
Join Date: Oct 20, 2004
Posts: 4
bennybenz is on a distinguished road
Default

Perhaps it really amounts to what HomieG said with the impedance. Perhaps the solder job is attenuating the signal too much.

So if I'm to try using the connector heads for a cleaner connection (and hopefully a constant impedance across frequency), I'll need a male and a female and some crimping tool. Can anyone point me in the right direction?

Thanks!
bennybenz is offline  
 
 
 

Go Back   SIRIUS Backstage Forum > >


Digitalradiocentral.com




Similar Threads
Thread Thread Starter Forum Replies Last Post
Terrible Reception Problems in DC/NoVA lukinva Install Garage & Help Desk 1 05-25-2006 11:48 AM
Problems with reception on JVC KT-SR2000 sjuhawks19 Radios & Receivers 8 01-25-2006 10:25 AM
Having car reception problems with Sanyo CRSR-10... mmgirl Install Garage & Help Desk 2 01-18-2006 03:05 AM
Reception Problems - Little help? hyzdufan Install Garage & Help Desk 1 12-17-2004 07:56 AM
RECEPTION PROBLEMS - ABOUT TO GIVE UP mikevirus Install Garage & Help Desk 3 11-25-2004 07:25 PM

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:47 AM.
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
Search Engine Optimisation provided by DragonByte SEO v2.0.39 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
All Content Copyright SIRIUS Backstage. All Rights Reserved. SIRIUS and registered trademarks are the property of SIRIUS Satellite Radio, Inc. The opinions posted on SIRIUS Backstage website and forums are those of the individual posters and/or this website and are not necessarily the opinions or positions of SIRIUS Satellite Radio, Inc.