Sources of Interference with FTA Reception

[spongella]

In the past I have heard folks talk about possible radio transmission interference with an FTA signal such as nearness to adjacent satellites and terrestrial interference. I can understand how an adjacent satellite can cause problems if the downlink signal is close to a neighboring satellite.

But what about terrestrial sources of interference? Ok, so the LNB converts the downlink signal to an IF, which can range from about 1Gig to about 2 Gigs, depending on the location. So what would be in that range of terrestrial radio comms (1000 - 2000 MHz) that would interfere? Certainly not the 800 MHz cellular band but there other cellular services operating at higher frequencies that could interfere. Bluetooth and most wireless servers are operating around 2.5 Gigs, so that would not be a problem (I think). I think drones are up around 2.5 Gigs too.

ADSB signals are on 1090 MHz, and there are other services such as GPS, Radar, Aero telemetry, and Radio astronomy that are found in the 1 - 2 Gig range. Then there also might be harmonics of lower frequencies that could possibly interfere.

So what would be some of the common terrestrial sources of interference to an FTA signal that one should be aware of, and are there any ways of minimizing them?

Thanks.

 

[FTA4PA]

Terrestrial mobile and Wimax are big ones (and may get bigger) . Terrestrial mobile: http://www.satelliteguys.us/xen/posts/3610011/ and a member with what turned out to be a Wimax interference issue: http://www.satelliteguys.us/xen/posts/3548188/

 

[waylew]

Radar

 

[FaT Air]

Think in total, there's been a few threads (3?), that turned out to be 3.5Ghz WiMax interference. But using that as a search returns too many to 'nail them down'.
Then the radar bands look to overlap http://www.aewa.org/Library/rf_bands.html

 

[Titanium]

Interference in the IF (intermediate frequency) range (950 - 2150MHz) isn't a problem when using quality coax, connectors and a shielded tuner on the STB.

A few additional RF noise sources not mentioned are microwave ovens, cordless phones, wireless video senders and other devices that may emit out of band signals.

 

[spongella]

Thanks for the info fellas. Never heard of WiMax, but if you think of it an LNB is a down converter and would convert any signals in it's operating range to an IF that could interfere with reception.

Not sure what that interference would look or sound like though.

Looked up the WiMax frequencies - 2.3, 2.5, 3.8 gigs for the USA. 3.8 Gigs would be in the C band downlink signal range, but not sure how much power these WiMax devices put out.