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nklb
Premium
join:2000-11-17
Ann Arbor, MI
kudos:2

[DISH] Dish box causing 2.4GHz interference

Click for full size
~5 mins of spectrum
I was recently attempting to help a friend troubleshoot a 2.4ghz wifi issue. Sometimes there was so much interference that the SSID could not be seen when in the same room as the access point, and on any channel the connection would periodically just drop.

I brought over a spectrum analyzer, and was able to track it down to the Dish network box that connects to the TV in their main room.

Any idea why it would need to be putting out so much noise all over the 2.4GHz spectrum? It has two peaks, but also seems to put out light noise over the whole spectrum. (With it off I do not see all the noise you see here; I didn't happen to grab a screenshot with the receiver off, but suffice it to say it was far less noisy across the entire range)

The receiver used two separate channels, one that seemed to stay on 2.438 and the other kept channel hopping, making no wifi channel safe to use for long.


ilikeme
I live in a van down by the river.
Premium
join:2002-08-27
Sugar Land, TX
kudos:1
RF remote controls?


nklb
Premium
join:2000-11-17
Ann Arbor, MI
kudos:2
There is one remote control that says UHF on it (the other just says IR) however it is a simple battery powered device, and holding it up to my spectrum analyzer I didn't see anything anomalous like this, even when pressing buttons.

The signal is definitely coming from the dish box itself.

videonex

join:2001-07-22
reply to nklb
Is the box using wi-fi to connect to the internet for updates, etc? It would have a dongle plugged in to the USB port on rear.


nklb
Premium
join:2000-11-17
Ann Arbor, MI
kudos:2
said by videonex:

Is the box using wi-fi to connect to the internet for updates, etc? It would have a dongle plugged in to the USB port on rear.

I'm not sure about that, but the interference is not wifi. Wifi has a distinctive curved appearance on a chart like this; not a sharp spike. (Also, wifi has mechanisms to allow multiple networks to coexist on the same channel.)

This looks more like what I see when I turn on a microwave oven.

videonex

join:2001-07-22
said by nklb:

I'm not sure about that, but the interference is not wifi. Wifi has a distinctive curved appearance on a chart like this; not a sharp spike. (Also, wifi has mechanisms to allow multiple networks to coexist on the same channel.)

This looks more like what I see when I turn on a microwave oven.

I hear you. Just a thought.

I have some cordless phones that use that band and they kill my wi-fi whenever they ring or are used. Looking for any kind of answer that might make sense.


ilikeme
I live in a van down by the river.
Premium
join:2002-08-27
Sugar Land, TX
kudos:1
reply to nklb
Could also be bad shielding on the line from the dish or something internal. I think the signals it picks up from the satellite in space are somewhere near that range, but not 100% sure.


nklb
Premium
join:2000-11-17
Ann Arbor, MI
kudos:2
said by ilikeme:

Could also be bad shielding on the line from the dish or something internal. I think the signals it picks up from the satellite in space are somewhere near that range, but not 100% sure.

Certainly a possibility, although the way the one keeps channel hopping makes me think it is intentionally put out by the device for some reason.


Vchat20
Landing is the REAL challenge
Premium
join:2003-09-16
Columbus, OH
reply to nklb
Specifically which model box do you have? This could help tremendously in terms of figuring what internal features could exhibit this issue.


nklb
Premium
join:2000-11-17
Ann Arbor, MI
kudos:2
said by Vchat20:

Specifically which model box do you have? This could help tremendously in terms of figuring what internal features could exhibit this issue.

I requested the information from my friend, and the model is Vip722k


guhuna
5149.5
Premium
join:2001-03-31
Port Costa, CA
Reviews:
·PHONE POWER
Hmm, I've got a 922, 722k, 722 and a spare 622 and don't have this issue. Now that doesn't mean it doesn't exist but I've never seen one cause this type of problem. The box talks to the LNB on 950-2150MHz.
If you guys really think its the box you can get it replaced, just call them up and tell them it fails up power up. Usually you'll get a replacement within 3 days. Its worth a shot and wont cost you a dime.


treeman
Premium
join:2000-07-15
Mcgaheysville, VA
reply to nklb
• DISH CommTM Technology† will allow phone and audio data to be sent throughout a home over existing power wiring. Requires only one phone line connection among all DISH Comm-enabled receivers in a home.


pende_tim
Premium
join:2004-01-04
Andover, NJ
kudos:1
Reviews:
·Comcast
reply to nklb
Turning off the receiver does little to shut down the electronics inside a Dish or D* TV receiver.

You have to unplug it from the 110VAC. Try unplugging all the receivers and any other power associated with the Dish and see what happens. Then power them up individually to find out the culprit.

Since you have access to a SA, I am sure you are smart enough to know the drill...

Tim
--
The difference between genius and stupidity is that genius has its limits.