XM Signal Strength

I moved to the East Bay about 14 months ago, and have found more dead spots than I ever had in the DC area.

Nothing has changed.. XM's birds haven't moved and they are still sending the same signal to XM receivers.

Try swapping the antennas. Maybe buy a new antenna and try it out on one or both of your cars.

Are or were you driving in an area that is equipped with any terrestrial repeaters? Because the way the system works is that the receiver will switch to a repeater if available without you being aware. If a repeater(s) were out of service, you could be defaulting back to satellite reception, which would explain decreased signal strength.

I have not noticed any changed in my XM........

+1. fastl hit it right on the mark.

Cheers,
Eemrek

FWIW, I'm in the East Bay too and the dead spots are painful. Is there a way to figure out where the repeaters are as they aren't where I live (Walnut Creek). Frankly, XM has been better than Sirius (I had both), but since the merge both are pretty hard to listen to these days due to drops. Specifically, I now get drops from small overpasses on the I-680 coming up the corridor at 75MPH (less than maybe a second under the bridge).

Does someone have a map of the repeaters? Is there a way to request repeater coverage?

I'm in the same part of the East Bay that you are, teamills, and there are many more dead spots than in the DC area. I would never lose the signal going underneath highways in suburban MD -- but I lost the signal every time I go under 680 out here.

...Does someone have a map of the repeaters? Is there a way to request repeater coverage?...

Well, I used to have a copy of the Boston repeater database complete with URL link, but I can't figure out where I stashed it! Anyway, if you go poke around the xmfan.com website, you should be able to find a link to the FCC website database location.

But have they throttled back on power for some reason? Maybe to save power or extend the life of the sat equipment? Over the past year I have noticed more dropouts, even when there are just trees over the road. This is a road I drive on every day, with different cars, that never used to have problems. I'm far enough out of town to not be receiving any terrestrial repeaters (I do know where they claim to be.)

I wouldn't expect S/XM to own up to something by themselves. They'd much rather raise rates or otherwise screw customers.

I don't have any proof to back this up but I'd swear the same thing.

I think I get more dropouts today (outside of terrestrial repeater areas) than I did 3-4 years ago.

Like I said - no proof. Just seems to drop out when there's just the bit of something in the way when before it'd have to be something fairly major like a mountain or really thick tree cover, etc.

Hi,

I'm having the same problem as many of you are describing here but with my "stationary" "at home" setup... constant reception of signal "dropouts" (the stations, come and go, for lack of a better description.)

I followed all of XM's "technical" suggestions" from getting periodic "signal boosts or refreshes" to purchasing a replacement Onyx XM radio/reciever but no solution to the problem.
I've had this same setup (same antennae, same location on my house etc. for about four years with no problems until recently).This problem only seemed to surface over the past month or so. So, I'm wondering what has changed to enable such "lousy" reception ?

It would be wonderful if someone with more knowledge and experience on this board than I would sound in on this frustrating situation. (Obviously XM is either incapable or unwilling to offer a solution.)

I love XM's programming and the variety of their channels but, right about now terrestrial radio is starting to sound pretty good again.

Hi,

In relation to the previous posts re: XM signal strength........

Someone recently suggested to me that one of the reasons for signal strength "drop-out" and "fluctuations" in my XM "home" stallation might be an interference issue.

Specifically, there are neighbors in the general vicinity with Satellite dishes and their own XM Satellite Radio installations and it has been suggested that these other satellite sources might be the cause of some of these signal "dropouts"and interference.

The only strange part is (as previously mentioned) that up until about a month ago there were no problems with drop-outs and reception and my at home installation has remained the same throughout the four years or so....same antenna location, no new construction in the area etc.

The other "odd" thing with this issue is that some of XM's stations come in with with reletively decent signal strength while with others my XM tuner seems to b constantly "aquiring a signal"

Perhaps I need to relocate my antenna ?



Does any of this make any sense ? Thoughts and opinions would be greatly appreciated.

Your best bet for home use of XM/Sirius is to use a Sonos player. They use the internet so you have to increase your subscription but the quality is great and no worry about antenna direction and reliablity.

So, at the risk of being redundant let me see if I'm drawing the right conclusions about my XM signal "issue"....

A.) It is definitely more than possible that other satellite installations in our nieghborhood (i.e. Satellite TV dishes and other XM anitennas) might be causing my XM signal to more than periodically "drop out" ?

B.) (This is a strictly "non-technical" observation) XM's signal can be so "delicate" and undependable at times that the above-mentioned poor signal can almost be a daily fact of life ?

XM has no system of "shielding" other, neighboring satellite signals to provide a subscriber with at least an adequate listening experience ?

C.)The only way of solving this problem is to invest an additional $300.00 or so in a Sonos player ?

If you're just trying to get signals into your house:
- get an outdoor antenna (Pixel makes a good one - about $100)
- get an XM Repeater (you may have to dig but you should be able to find one)
- plug it all in an enjoy - As long as you place the antenna somewhere facing South you should be OK.

This is the current setup I have and it works quite well.

Earlier I thought we were talking about mobile signal strength.

No need to buy Sonos.

Thanks Brda for your help and suggestions.

I already have an outdoor antenna supplied with my original XM reciever.

May I ask the purpose of a "repeater"? And where is it installed.... on the antenna line between my XM reciever and the outdoor antenna or is it part of the outdoor antenna configuration?

(I contacted XM for about the tenth time and they suggested that the outdoor antenna was at fault and shound be replaced. Luckily I have a brand-new replacement.)

Thanks,
Bob

just bought a new vehicle w/factory xm.my wife has xm in her car and i had $60 xm onyx on my last car.i now have drpouts in in places i or my wife still doesn't,and looooong dropouts in places i only had short ones.i believe its antenna,dealer says "gee,never heard of that".2012 hyundai santa fe.

Let's see if I can clear-up some confusion. Let's go back to basics...

XM and Sirius work on S-Band frequencies. These frequencies don't require exact pointing, which is why you can have a small antenna on your car and not require the antenna to point in one direction. These frequencies are in the 2.2-2.3 GHz range.

DBS (small satellite) uses Ku-Band and Ka-Band (DirecTV only) frequencies which are in the 12+ GHz range. The LNBs convert the signal coming from the dish to a lower frequency in the L-Band range (1-2GHz) before the signal comes in the coax into your house. At no time (unless you get Internet over your small dish) does the small satellite TV dish transmit any signal and the frequencies with the small dish do not overlap any frequencies used by satellite radio. So, unless your are running the antenna wire right through a small dish or even parallel to the small dish'es coax, this is not going to interfere with your satellite radio signal.

There are terrestrial repeaters used in the S-Band as well. As part of satellite radio's agreements with terrestrial broadcasters (AM / FM), satelliite radio agreed to limit the number of terrestrial repeaters used. The two (now one) satellite companies didn't always follow these rules and the terrestrial broadcasters complained. The FCC proposed rules and the number of repeaters was reduced. Here's one of the rule changes being proposed back in 2007,

http://www.orbitcast.com/archives/fc...n-tuesday.html

So, a reduction in the number of repeaters near you is a possibility for a true signal strength reduction. You would now be picking up a repeater that is further away.

However, I'm guessing you are using signal strength in a generic way. Basically what you are getting are more drop-outs. If so, there is a second explanation.

Satellite radios all had 10 second buffers when the service was first offered. Go under an overpass and the radio's buffer would already have the next XX seconds of programming and your radio kept playing without interruption. It's great except that meant the signal had to contain 10 seconds of programming at any given time but that was the only way to overcome blockages while driving where repeaters were not present. I borrowed this explanation from another forum from 2005 on how the XM buffers work (Sirius is different but similar),

"Each satellite puts out a direct feed and a delayed feed. Your receiver samples up to five feeds, a direct and a delayed feed from each of the two active birds plus a terrestrial repeater and while each of the five signals are coming and going, fading in and out, derives an audio output from the five received signals that is close to 100% solid."

Over the years as the number of channels have proliferated but the bandwidth has remained constant, satellite radio has had to find more ways of cramming more channels into the signal. One way has been less bits per channel, but another way has been to reduce this buffer down. I'm hearing about a 2 second buffer now. So passing under an overpass for more than 2 seconds results in loss of signal momentarily. This would also be true with moist tree leaves (really good blockers for S-Band) but not for rain which S-Band goes right through. I suspect the reason for the lower amount of buffer time is mostly to save bits when compressing since the current and delayed signals would be more similar but I don't have any technical documentation to back that up.

So combine some wet leaves with a reduced amount of buffer, and you would get more dropouts.

The only way to stop this would be if Sirius/XM starts adding more buffer back to their signal. We used to be able to drive under any overpass without a repeater and not lose signal. Now about half of the time the signal drops for a second or two. One effect of the merger was that both Sirius and XM broadcasts had to add a large number of channels to each channel lineup and this means less bandwidth per channel, including the buffer size.

A third possibility is that the antennas have gotten smaller and smaller. This is done by using more and more power to the antenna to boost the signal. This is another situation where the lack of buffer combined with a greater chance of a signal drop-out due to the smaller antenna makes for more interrupted channels. A smaller antenna may mean more of a chance of programming loss.


And, yes, placing your antenna outside facing south is the best way to get maximum signal strength. S-Band is omnidirectional, so exact pointing does not increase signal strength. For XM, these are geostationary satellites (unlike Sirius) which is why south facing is important.

Also make sure when calling Sirius/XM customer service that you ask where the customer service rep is located. I've found that when you get the Phillipeans that your odds of getting a correct answer have gone way way down. Don't assume their customer service reps have ever even heard a Sirius/XM broadcast.

Great post.

Thank You ALK3997,

So, the "buffering" problem you described would be one explantion why "some" XM channels come in at varying signal strengths at different times of the day? I guess I'm thinking in sort of "terrestrial radio" mindset, because I assumed that if one XM channel had good signal strength, then all of the channels should have same, "across the board".

Before the XM/Serious merger, these problems did not seem to exist.

thanks alk3997.the info about my radio having a shorter buffer time explains why maybe my wifes does abetter job than mine.thanks again.

I'm not sure I can answer your signal strength question without knowing how you are measuing signal strength. If it is by the four bars on the signal strength display, those are really measures of signal quality (the number of bit errors in the signal). So that could be caused by everything from wet leaves to the sensitivity of the radio compared to another radio.

Satellites work by transponders (even those in the S-Band) and each of the transponders has a different output power (although they are supposed to be similar). So, you may see different output power on different channels.

And, yes, they crammed more channels into the fixed bandwidth when the merger occurred. Less bits per channel. More opportunity for interference to cause a larger problem.

Well, I've been wondering what the heck was going on!. I live in a very rural area and sometimes when things are really growing I can have a signal drop off. But lately I've been noticing it happening far too often. This is on my old XM Roady that I've had for about 6 or 7 years. I use it for my house radio now.

From another site I learned some time ago how to check for the best signal, it's probably been discussed here before but I will go over it again and this only applies to XM radios. With the radio off press 2-0-7 and the XM button or enter button. This turns the radio on and if you go to the third display you will see a selection that will show you how many burs you are receiving. On the left is signal from the South satellite which I believe is for the Eastern half of the U.S. On the other side I know it's for the West but I forget where the satellite is located. I have no idea what the middle signal is for.

Now the way I have my antenna situated (indoors) right now is completely flat. The signal being received is from the Southern satellite. I'm getting burs of 0.1, to about 2. That's a pretty good signal, you shouldn't lose reception until it goes beyond 5 burs.

But what I'm also seeing is the burs jumping suddenly to up in the 60's and 80's. Then it drops back to a 0.2 or well below 3. I couldn't figure it out, leaves are falling I should be getting a real clear signal by now.

So this shorter buffer could very well be why I'm getting these weird signals I'm seeing. Thanks for the information. It sucks because it's annoying though.

Wow surprised this thread is still alive.

Anyway I'm now in a similar boat as many, signal issues. However my issue is even odder and not mentioned, I only have no signal on channels 79 and lower, 80 and above works fine. From what I've read that is other channel point in which the transponder used on the bird is different. Now that said I've never had this issue in the many many years of service and my antenna hasn't moved an inch. This leads me to think they are doing some monkeying with the power on one of the transponders, it's rather annoying, though not surprising as the company has taken a major nose dive in quality since the merger.

If that was the case, my radio would not have those channels, too. I would try a reset on the radio (if that is an option). If that doesn't fix the problem, I'd next have a rehit sent (call SiriusXM and selection option for reauthorization). If that didn't work, I'd start suspecting a problem with the radio. It is never normal for a signal to go completely out for extended periods of time (> a few seconds) unless under a covering (wet tree leaves are a covering).

That really sounds like a radio problem of some type (including an authorization problem).

No that's not the case. If I hang the antenna out a window it's fine, but when I put it back inside in the spot it's been for years then the signal on only lower channels drops to 0, higher channels work fine and I get about 75% signal. This is why I'm thinking that they have been messing around with the power and or moving channels around on the birds/transponders, less power = less indoor signal.

I'm late to the game here, Had XM on my 06 Cobalts, and the stations sounded pretty good, we never had drop outs, even in my garage we had signal, but now we have a 2012 Equinox, and it sounds like crap, like a 32kb MP3 almost, and drops out regularly, I'm guessing this is because of the merger and needing to fit more channels over the same bandwith? If so, I will not be "Renewing" my subscription. (It's no longer advertised as CD quality radio)

Maybe not. If the change in sound quality happened when you changed vehicles, it is likely the new vehicle with the audio problem. The content of the XM transmission didn't change just because you got a new vehicle.

It may be that your Equinox uses an XM tuner that isn't as good as your Cobalt's. For the drop-outs, it is likely that your new vehicle's antenna is higher from the ground and therefore more of the garage is blocking the signal. It may also be a smaller antenna than the Cobalt's.

So, while I wish I could magically improve the XM audio quality and make it closer to CD, I think in this case it may be your new vehicle causing the problem. Unfortunately, the only way to know completely would be to compare the two vehicles side-by-side.

unfortunately, I don't want to pay $200 bucks for the adapters needed for XM in the cobalt with the new radio or the xm fee to check if it still sounds better. Thanks though.