HID Light + Cable modem = Some sort of interference

Long story short, if my grow light is on then everybody on my block has tiny rabid hamsters crawling out of their internet cord to feast upon the delicate bits of their anatomy.  Or at least that's the way my ISP is describing it because they're unable to handle some interference my light is apparently putting out.
 
I assume I just need to string the coax & cat5 cables so they don't go anywhere near the light, but the ISP sent somebody out for a few minutes, unplugged the light, and said that was the solution.  I'll rewire some things and reconnect it when I get home tonight but thought I'd check with you guys as well.  Do any of you have any sort of electrical knowledge that could shed some more light on the situation than "electrical device + long ass antennas = bad"?
 
Anything in particular to watch out for, any sort of filters that could be installed, etc?  I have an understanding of these things while they remain within the wire, but it all gets pretty handwavey once you get outside the wire.
 
Interesting.
 
My coax is about 1' from the HID light and I don't have any issues. About 5' away from the ballast. The Cat 5 is in the other room though so it isn't even close. .
 
What type of HID ballast do you have?  The budget systems from Apollo and iPower are famous for RF interference issues, so bad that re-routing cables won't fix the issue unless you have a large house and can completely separate it from any electronics.  A good friend and fellow grower of mine had an Apollo unit in his garage and it would screw with his tv remotes, cell phone coverage, and especially his internet service.  He sold the ballast and bought a unit from galaxy...never had another issue.  There are tons of stories on "other" forums that go into great detail about these issues. 
 
That could be a number a things. A good surge suppressor will filter out noise caused by defective capacitors in a ballast power supply. 
It's also not uncommon for a faulty rf  device to back feed through the neutral wiring (which acts as a antenna). A loose connection or floating/ no ground to your light is another possibility.  There's other possibliities....at least you narrowed it down  
 
600W HPS Digital Ballast, Bulb
600W HPS Digital Ballast, Bulb and Economy Reflector Combo- 120/
 
Cost about $210 plus shipping.
 
That's a copy/paste from the email I got when I ordered it.  Not sure if that gives you anything to go on, I don't recall anything more specific and can't look at it until I get home in a few hours.
 
That sounds like ingress onto this network which was then causing noise onto the network which was then returning to the amp and knocking off neighbours around you.
 
usually causing by slack f's or rf connections especially at modems or cable STB. I have never had it before from a set of grow lights in terms of noise but I have had similar stuff like energy saving, LEDS and certain grow light interfering with wireless signal due to them broadcasting a frequency which causes interference to receivers such as laptops etc.
 
so I wouldn't be surprised if it could cause ingress onto a cable network, but usually when everything in the house is tightened up the noise stops.
 
your lucky your not a customer with the company I work for as we would of cut your services!
 
I don't know how strong of an magnetic interference a ballast would emit to be able to affect the neighbourhood but I would assume the problem is not wires running parallel but the problem is much more likely a ground loop issue.
 
As above, the ballast could have poor grounding and is transmitting noise. Its kind of similar to a car how when there is poor grounding to the audio system, electrical noise from the alternator can be transmit via the wiring, amplified by the head unit and emitted by the sound system.
 
I had a ground loop issue at home where if I had my desk lamp on while my sound system was on, the home theater subwoofer in the other room would hummmmmmm. If you have a cd player connect it to the same power outlet as the ballast and then use a set of headphones in your cd player to see if you get any noise when the HID light is on and gone when its off. 
 
Electrical noise has no barriers, if it affects your modem, it can travel down the signal any which way it likes. Ultimately the signals which come through the cable modem(at least down in Australia) are extremely high frequency, they could be jumbled by any noise. Poor f connections will also result in an increase SNR which can amplify noise. There are far too many variables. Sure the HID is causing interference but you aren't the only person in the world running a HID with a cable modem...
 
Sounds like a grounding issue to me. I would start by checking the wall socket you plug the light into, is it 2 wire or 3? has the ground (bare copper wire) been run to the box or socket or is it daisy chained with a marrette? Be sure to lock out that circuit in your braker box before removal
 
Bit of an update.
 
The outlet the light was plugged into didn't have a proper ground.  Traced it back, and whoever wired it up was apparently confused by this funny looking third wire so they just snipped it off at the junction box....  Anyway, sorted out the ground issue only to discover that was a red herring.  Interference remains after proper grounding.
 
Did some searching around and apparently the pot growers are more familiar with the issue.  These cheap ballasts are apparently known for just spewing a crapton of interference out and the coax is perfect at soaking it up and sending it to ISPs.  I've removed the coax from that half of the house, turned the light back on full time, and I'm waiting for the ISP to let me know if there's still interference coming from the house.
 
If so, my next step is to build some sort of Faraday cage around the ballast.  Wrapping foil along the length of the cord to the light is the final possible step.  Beyond that, I think I'll just need to unplug the light and replace it for next year.
 
Apparently you can check for interference rather easily with a portable AM radio, but I don't actually own one.  The pot growers say you can find the houses with cheap lights by driving down the street and triangulating the interference.
 
Wulf said:
Bit of an update.
 
The outlet the light was plugged into didn't have a proper ground.  Traced it back, and whoever wired it up was apparently confused by this funny looking third wire so they just snipped it off at the junction box....  Anyway, sorted out the ground issue only to discover that was a red herring.  Interference remains after proper grounding.
 
Did some searching around and apparently the pot growers are more familiar with the issue.  These cheap ballasts are apparently known for just spewing a crapton of interference out and the coax is perfect at soaking it up and sending it to ISPs.  I've removed the coax from that half of the house, turned the light back on full time, and I'm waiting for the ISP to let me know if there's still interference coming from the house.
 
If so, my next step is to build some sort of Faraday cage around the ballast.  Wrapping foil along the length of the cord to the light is the final possible step.  Beyond that, I think I'll just need to unplug the light and replace it for next year.
 
Apparently you can check for interference rather easily with a portable AM radio, but I don't actually own one.  The pot growers say you can find the houses with cheap lights by driving down the street and triangulating the interference.
Is it Rogers Cable there? Ask them the last time they did a flyover to check for leakage. Coax by design is to shield interference from the outside, and to keep the signal on the inside from escaping. It is either bad coax, bad fitting, bad splitter, loose fitting or bad device (TV or cable box). That is it. Doesn't sound like they have very clean coax plant. If your interference in getting in, I guarantee you their signal is getting out. They could be fined here in the USA by the FCC for this. This is why they do flyovers with a small plane and sniff for signal leakage. Easy way to Cover a large area and triangulate. (I used to do cable installs.)
 
I've heard the same, Apollo and iPower digital ballasts can produce RF interference for 1/2 of your neighborhood. I'll bet that clone ballasts that come out of the same factories will have the same effect.
 
And in those same discussion threads, i've heard that Lumatek digital ballasts do not have that issue. I don't know if old fashioned magnetic ballasts (like the HTG ballasts) have that problem, i don't recall hearing of any.
 
It never seemed like the cable companies had much patience with the offenders, i'd look into correcting the problem before they contact you again, or cut off your service.
 
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