Interferance from digital ballast?

I have a 400w digital ballast and whilst researching another topic tonight I came across a thread involving interference from digital ballasts. My internet (2mtrs away in next room) has been playing up since I got the ballast , but I went out to the car (8 mtrs away) and all the am stations work with no interference, so I guess the question is the interference limited to a short space? And am I being overly paranoid?

No you are not being paranoid. If it is interfering with yours then it may with a neighbors as well. That is when the utility companies send out signal vans to find the source of interference. ISPs do this routinely and many on RIU have posted on this.

Now, as a musician who uses lots of electronics, you can do something to help mitigate. On eBay there are people selling sheets of copper. Build any kind of enclosure than can hold these copper sheets. Even a cardboard box lined with it. Those who claim copper cannot shield from EMI/RFI know nothing. MRI units are enclosed in copper - the entire room it is in - just for this reason.

Your ballast is friendly to X mHz and is basically broadcasting on that wave length. Broadcasting what comes through to your ear as static.

ok thanks, is there a way to block the interference, or do I need to get a magnetic ballast.

Uhm... dude... ballasts don't fuck with your internet. My router was plugged into the same fucking power strip as my 1000w Mag ballast.

You're trippin.

And pardon my french.

BTW - for those who cannot reason much - your enclosure must be totally copper lined. EMI/RFI is like water in that it can find a chink in the armor and escape. And multiple layers of copper, separated by cardboard, are even more effective at blocking unwanted signals.

Krondizzel said:

Uhm... dude... ballasts don't fuck with your internet. My router was plugged into the same fucking power strip as my 1000w Mag ballast.

You're trippin.

And pardon my french.

Click to expand...

Actually he isn't with the digital ballasts. It depends on the frequency each ballast emits.

And ALL transformers emit EMI/RFI. It seems the new digital ballasts simply occupy bandwidth they are not wanted in. So even old magnetic transformers like I use can do this.

Krondizzel said:

Uhm... dude... ballasts don't fuck with your internet. My router was plugged into the same fucking power strip as my 1000w Mag ballast.

You're trippin.

And pardon my french.

Click to expand...

haha, I HOPE I'm just trippin bro.

steveng said:

haha, I HOPE I'm just trippin bro.

Click to expand...

Well... I don't second guess Harley much so I suppose it is possible. I haven't had a single problem though and I use both mag and digital ballasts.

The ONLY reason I believe this is there are SO many complaints by growers who have had the knock on their door by a cable TV guy who is asking about possible trouble or looking for the source of it. A search on Google brings back tons of results on this - nearly 100% by pot growers. Here on RIU we have posters who very recently have had that knock. It ain't by chance, fellows! And it is NOT all the newer digitals it seems. Maybe someone should start a thread asking about the knock and what model/brand ballast they use. And it's the cable companies that provide internet service in bundles I guess. And they locate these troublesome signals by traingulation and can pretty much narrow down the coordinates of where the source is coming from.

As an aside this friend of mine (long in prison now for obvious reasons) had a radio jammer from WWII. You would crank this critter and it played hob with radio and TV signals. We would sit in his garage and crank this thing for 10-15 minutes (and that was a task let me tell you) then go outside and watch the rubberneckers looking at the telephone poles and asking each other why their TV or radio was screaming. We got caught (rather he and Jeff did) when the vans located the source during one of this 15-minute runs. The jammer went away with the FCC man.

Interesting. It's a frequency conflict with the cable company?

Krondizzel said:

Interesting. It's a frequency conflict with the cable company?

Click to expand...

Actually it appears its a bandwidth problem when the digital ballast is near the same wavelength as somebodys WiFi router. And the cable companies seem to get involved if they supplied the router. They choose their routers based on occupied bandwidths, expecting little to no interference from signal sending objects or apparatus. To send signals you are required to have a license and be identified and your transmitter location registered with transmitter readings verified by a 1st class FCC engineer. Whew.

So equipment is chosen for regions by utilizing bandwidths reserved for such purposes. Now it seems some digital ballasts emit EMI/RFI in wavelengths that cross or interfere with other low-amplitude signals. It seems this is when the growers cross paths with the WiFi users next door. And this interference is that low amplitude, hence the effectiveness of signal shielding. I know with solid state amps and pedals and effects we get all sorts of shit from neighboring businesses if there are sensitive electronics in close range. A PC shop next to bar.

Well... damn... Thanks Harley.

One last bit of proof (if it is). Fluorescent light fixtures suck ass in bars. The 60-cycle interference is picked up, as RFI, by almost any solid state (and even some tube amps) and comes through your pristine speakers as a buzz or hiss. We hate it and hate fluoros near the stage for that reason. We insist they be powered off during play.

Ok, thanks for all the replies guys. So as I said the net connection was losing bars and playing up and then several tv stations went all funny (broken/pixelated ). Obviously needing to do something I did some more research and I learnt that wrapping the ballast power cord in foil will (can?) reduce rf interference by 50% so I did that. Then I positioned the ballast box in a container wrapped in foil with a bit of scrunched up foil placed touching the ballast box inside. Now, there is no more interference on either tv, computer or am radio. Also, the digital ballast in question is a relatively cheap no name chinese item so I'm not surprised I'm experiencing some problems! However, my dwc plants are growing very well so all is good at the minute.

A nice tin foil hat will finish off your ensemble. Glad you killed the source.

You're going to have problems when you buy the chepeast priced items that you can find on the internet. Why not buy decent quality products instead? How much did you pay for the el cheapo 400W ballast that you have?

Not just utilities, if it's bad enough.. they will also get the FCC involved.. and they can demand inspection of hardware with warrant. (if in the US) Believe me, when they're looking for amateur radio EMI/F and they find a grow operation, your headache went from normal to 'oh shit this is gonna hurt'.

"Abstract—The design of electromagnetic (EM) interference filters
for converter systems is usually based onmeasurements with a
prototype during the final stages of the design process. Predicting
the conducted EM noise spectrum of a converter by simulation in
an early stage has the potential to save time/cost and to investigate
different noise reduction methods, which could, for example, influence
the layout or the design of the control integrated circuit.
Therefore, the main sources of conducted differential-mode (DM)
and common-mode (CM) noise of electronic ballasts for fluorescent
lamps are identified in this paper. For each source, the noise spectrum
is calculated and a noise propagationmodel is presented. The
influence of the line impedance stabilizing network (LISN) and the
test receiver is also included. Based on the presented models, noise
spectrums are calculated and validated by measurements.
Index Terms—Electromagnetic interference (EMI), electronic
ballast, EMI prediction, EMI simulation, fluorescent lamp."

I have the entire 10-page PDF for those who think this phenomenon is not real. It's a research paper from an engineering firm regarding EMI by digital fluorescent ballasts. It specifically addresses the change in use from EM to digital and the source problems of EMI with these ballasts. Obviously not all ballasts are the same and a list of the worst offending systems would be interesting.