: FAQ - Signal Leakage Between CATV and OTA
2006-01-13, 02:15 PM
If anyone is contemplating running a combination of Cable TV and OTA to the same TVs or receivers, there are specific safeguards you must take to isolate the two signals from eachother. This is not a casual concern, its very important that you do it correctly!
Likewise if you are getting Cable TV channels on your OTA tuner, a neighbour may have a signal leakage problem.
Satellite and OTA into the same TVs or receivers are not a problem.
2006-01-14, 06:24 PM
Would you care to elaborate Stampeder? I have a few friends who have purchased new TV's with integrated ATSC tuners, who also use analog cable (too cheap to spring for HD terminals). What precautions should one take? TIA!
2006-01-14, 06:46 PM
Gladly! Here is the situation: you have two signal sources that are feeding your TV using essentially the same frequency ranges. OTA antennas feed VHF Low, FM Radio, VHF High, and UHF to your TV, but so do CATV systems, albeit with their own sub-channel maps over the same frequencies. They do not get along with eachother.
This frequency overlap is due to historic reasons because in the 1950s-60s there were no Set Top Boxes yet for cable channel tuning, so the CATV providers had to overlap the regular 13 VHF channels and later the UHF channels with their own signals in order to feed your TV. This is why CATV gear is so heavily shielded to this day - there is a direct conflict with OTA. If we could redo CATV all over again I'd advocate assigning a third range of frequencies apart from TV and Satellite.
So, if you simply connect the antenna and the CATV with a splitter you will cause signal leakage of the CATV signals through your antenna and vice-versa, which will cause garble and interference not only for yourself but for your neighbours too. Connections like that are ILLEGAL. Industry Canada and CATV providers constantly check for signal leakage and will come down really hard on you if you let it happen. The leakage problem does not happen with Satellite because its incoming signals are way off in another part of the frequency spectrum from TV.
What is the solution then? An A-B input switch is one method, or if your TV has 2 coax inputs you could test to see if they are discrete (separated inside to prevent leakage). Some people run the OTA lead right into the TV and the CATV lead into the VCR and then over Composite or SVHS into the TV. There are a few solutions like that if you think about it. I think there might be remote control capable A-B CATV/Antenna coax switches out there too.
Check out previous posts in the OTA Forum by HDTV101 and others about this issue.
2006-01-16, 05:24 PM
The easiest way to check for leakage between 2 sources is to disconnect the regular TV's CATV and OTA inputs and put a portable TV with rabbit ears right beside it. On the portable TV do a full channel scan of both TV and CATV and make note of which channels you receive and also which other ones are really garbled.
Next, hook up the regular TV's inputs again and turn it on as well as any set top boxes needed, then on the portable TV do a full channel scan of both TV and CATV. If you are now receiving more channels than the with the first scans on the portable TV (even if they are garbled but strong signals) then you have leakage. If not, your TV is properly isolating the inputs.
Another thing you can do if you're not sure is check your TV's manual or contact the manufacturer to find out if they're isolated.
macker, let us know the make/model of your TV and what you find out. :)
2006-01-16, 05:43 PM
Be aware that if you use an RF Modulator to connect a DVD player, VCR, XBox, or other electronic gear to your TV because it only has a coax (RF) input, you must not put your RF Modulator and your OTA connection on a splitter feeding into the TV. If you do, you will cause signal leakage that will mess up everything you try to view and maybe that of your neighbours too. Industry Canada might even fine you when they triangulate in on your location.
2006-01-16, 10:23 PM
They probably don't care as much about interferance with OTA as with other services. Cable channels use frequencies other than TV, including aeronautical band, etc.
2006-01-25, 07:27 AM
I got a letter the other day that said I had Signal Leakage from my Rogers digital and had to call to book an appoinment from some company name Trinity, free of charge.
The person said the reason was caused was by the black wire, which my mom didn't say anything about cause it was from an illegal satellite we had. Of course it's not connected anymore but the dish is still up. Anyways supposedly it's responsible all of the sudden for the 'signal leakage'.
They said to call Rogers and get an appointment to clean up the cables. im apprehensive of making an appointment, as my past hacking days may find me in trouble. I noticed today 3 channels all of the sudden arent working[15,16,17] just black screen.
what do you recommend?
2006-01-25, 11:01 AM
Clean up the mess and call them.
I got the same letter about five years ago. Someone came to my house to check was was causing the leakage. He ended up replacing a splitter at no cost.
2007-06-14, 12:18 PM
Today I received a hand-delivered notice from Rogers that they have "determined that the television cable located inside your home is causing signal leakage".
They go on to threaten that "if we do not hear from you within the next two days, Rogers may be required to temporarily degrade your cable television signal".
Can anyone explain this to me? Are they trying to get in my house to see whether my cable is split? Do they not want me to use my own DVR?
They may taker out your spliitters if they do, replace them with better quality ones and they will not notice leakage, Industry Canada audit them for leakage so they have to go out and look for any point that leaks out signal.
2007-06-15, 12:37 PM
I received the same letter re: leakage (a great line from the film "Casino" comes to mind, "leakage my ba@#s")
They said that Industry Canada forces Rogers to monitor leakage as it may affect police/medical transmissions or something.
I called back the contracted company (not Rogers) and the receptionist was very nice. She said that since I called, they would not shut down my cable service. I made an appointment with a technician to come by.
This guy shows up and disconnects one of my cables cause it showed "leakage" from outside, even before ringing my doorbell. Then he comes in and wants to checks all my outlets. I said to him that they all have a signal so it must be the last outlet in my basement as it is not hooked up to anything.
You know what the problem was. The metal connector of the cable was touching the side of the metal receptacle box (there was no cover plate yet).
All I had to do was pull the cable out a bit.
Make sure you watch the guy like a hawk when he comes by.
2007-06-17, 10:58 AM
3.2 Leakage Control :
2007-09-28, 10:54 AM
Last week I had a note placed on my door from a Rogers subcontractor saying they had detected "signal leakage" originating from my residence, and stressing the need to repair it, free of charge.
I understand the need for this and it's importance so I will be calling. I am a legitimates subscriber to Rogers Cable and have nothing to hide as far as their line is concerned or the number of outlets.
But my delimma - I have a "Free to Air" system set up in my home running to four outlets and using two FTA receivers - essentially that gives portability of the receivers throughout the home.
Now my question - the Roger's sub will be coming to my home to look for signal leakage, should I yank out all the FTA equipment before his visit?
Signal Piracy is not condoned on this site.
If you aren't doing anything illegal then you have no reason to "yank" out the equipment.