Rfi question

[Complete Noob]

Looking to upgrade lights soon and I was lookin at hps

My first question is does a double ended unit give off less rfi compared to traditional single ended fixtures?

Second question involving ceiling height. I can pretty much put the light 7” high in the air. It this high enough for a 1000w, or will I have problems burning any reasonably size large plant?

Another thing I wondered is about rfi testing are there any videos or testing already done on major name brand ballast that I can find online?


I have been looking online for the longest on specific info dealing with rfi and all I can find are people paranoid with no real answers

 

[Complete Noob]

This one I’m leaning towards


https://growace.com/yield-lab-profe...MIxbHktZrS4QIVkVuGCh1WSASBEAQYBCABEgLm5fD_BwE

The powerhouse 1000 watt double ended Yield Lab lamp is run off an electronic ballast with an adjustable wattage range, enabling growers to change from 600 watts to 750, 1000 or even up 1150 watts! This customization means that the ballast is compatible with a wide range of double ended grow lamps. This light fixture has also been designed so that the bulb and the ballast are situated close to each other, minimizing the electromagnetic and radio frequency interference which can occur with other grow light fixtures.






They claim to base the design and features off of the gavita pro 1000w de. I also see the gavita is on sale everywhere right now for $330. What do you guys think

 

[PurplePotion]

Hey Noob. You’re in the same boat as me. So far I can confirm that my ION 315W Cmh and Nanolux DE Chill pass my AM radio test. Neither have any interference unless you stick the antenna within a few inches of the bulb, and even then it’s a very very very faint hum/noise. I can confirm that an older 1k digital se hps ballast FAILED my AM radio test horribly.. this is actually what started my research, discovery and nightmare that is RFI. As soon as the light kicked on the radio started screaming some god awful electronic noise. Unmistakable and literally took over the entire radio frequency band (not gonna name brand names as I’m highly confident no reasonable person would purchase it these day but I had a friend who offered it up so i tried it).

I also have 7’ ceilings. Confident I will be ok with the 1k nanolux de chill with properly training. I think I’m gonna try a gavita this round and see if I can’t get it to work with the low ceilings, if not I am leaning towards replacing the remaining 3 se 1k hps with nanolux de chills.

Rfi is real, but I’ve come to find that there are a handful of lights out there that are properly shielded, etc, and it only takes 1 bad apple to give you nightmares lol. Make sure all your wiring is up to snuff, especially ground loops (there should be none or as few as possible). This will aid in not further transmitting any rfi. I also believe that the “all-in-one” units are the least problematic in terms of rfi. The long wires used to run to your hoods and ballast do no favors in terms of rfi. If you are going to be using remote ballasts be sure to keep all of your ballast and lamp wiring as short as possible. Going to be testing some Rf filters soon as well.

If I were you I would give the Nanolux De Chill a shot. It’s going to be your best bet at utilizing 1k DE with these ceiling heights. Will help reduce a/c needs also.

 

[f-e]

Newer kit generally has a lower switching frequency, moving the harmonics down the bands. This means less of the higher frequency noise.

A typical switching regulator is around 100khz, putting it's fundimental frequency right in the radio band. It's first, and likely strongest harmonic is 200khz. Still in the radio band. It's much higher orders that are buggering up modern digital systems. If we use a 40khz pwm drive, it's first harmonic is 80khz. It's running out of power before we are as high up the radio spectrum. This is all a bit analogue though. Digital systems generally don't have a carrier wave. They just stream data, and the frequency is more related to timing. So other digital systems in tune harmonically, will keep knocking out data. With cable altering this in relation to capacity, you can trip it up at certain times, but not others. Making it hard to spot what's going on.

I simply won't use digital ballasts of that size, 12/12. Anybody with an AM radio that complains of noise 12/12 is almost saying what the noise is.

The idea of shorter cables, being a smaller aerial, seems sound. Aerials don't simply get better as they get bigger though. It's more about the aerial being measured in multiples of the wavelength they are transmitting. 6" of wire is about perfect for wiping out mobile phones. There is also mutual oscillation, where similar lengths resonate together. I can't deny that keeping the cable from driver to lamp in a shielded box is good though. If that were possible. Yet I don't see shielded cables used. Because ultimately the lamp will be exposed, and it's the element between live and ground. The real antenna. Driven at high frequency.

I like my lamp at mains frequency. Just like my aging bathroom extractor. My washing machine. The National grid distribution network, and nearly every installation connected to it. Mains frequency noise is everywhere, and everything is built it resist that particular hum. There is nothing random about it that could catch me out. Just normal.



Please understand that I'm touching more bases here than a fast food guy has any business knowing. Some will be wrong, but it opens up a few subjects for discussion, that might otherwise never get aired. Shoot away

 

[PurplePotion]

Glad you chimed in f-e. You are way more knowledgeable on all of this, and like you and I have discussed, if I’m unable to make my footprint nearly silent, I’ll be going with the mags.. just soooo hard to not be tempted by 1k DE lamps. Maybe it’s all just built up hype I have in my head but I’m determined to try (not stupid though and will not be running any sort of lights that cause noticeable interference for myself or anyone else). The DE Chill has been my only splurge hehe. The other lights are on ‘consignment’ per-se, so I’m not so hesitant to test those

Again.. so far I’m pretty happy with the DE Chill. Going to try to get some more accurate testing done and will report back in time.

P.s. f-e has several super valid points about magnetic ballasts. And just to establish, in simplistic terms I think our goal with these digital ballasts is to obtain a noise ‘signature’ that is unable to be detected outside of the immediate vicinity (very very very weak, so that it is below the threshold that affect other bands of communication). Rfi is an animal that Must be tamed !!!

 

[Complete Noob]

Newer kit generally has a lower switching frequency, moving the harmonics down the bands. This means less of the higher frequency noise.

A typical switching regulator is around 100khz, putting it's fundimental frequency right in the radio band. It's first, and likely strongest harmonic is 200khz. Still in the radio band. It's much higher orders that are buggering up modern digital systems. If we use a 40khz pwm drive, it's first harmonic is 80khz. It's running out of power before we are as high up the radio spectrum. This is all a bit analogue though. Digital systems generally don't have a carrier wave. They just stream data, and the frequency is more related to timing. So other digital systems in tune harmonically, will keep knocking out data. With cable altering this in relation to capacity, you can trip it up at certain times, but not others. Making it hard to spot what's going on.

I simply won't use digital ballasts of that size, 12/12. Anybody with an AM radio that complains of noise 12/12 is almost saying what the noise is.

The idea of shorter cables, being a smaller aerial, seems sound. Aerials don't simply get better as they get bigger though. It's more about the aerial being measured in multiples of the wavelength they are transmitting. 6" of wire is about perfect for wiping out mobile phones. There is also mutual oscillation, where similar lengths resonate together. I can't deny that keeping the cable from driver to lamp in a shielded box is good though. If that were possible. Yet I don't see shielded cables used. Because ultimately the lamp will be exposed, and it's the element between live and ground. The real antenna. Driven at high frequency.

I like my lamp at mains frequency. Just like my aging bathroom extractor. My washing machine. The National grid distribution network, and nearly every installation connected to it. Mains frequency noise is everywhere, and everything is built it resist that particular hum. There is nothing random about it that could catch me out. Just normal.



Please understand that I'm touching more bases here than a fast food guy has any business knowing. Some will be wrong, but it opens up a few subjects for discussion, that might otherwise never get aired. Shoot away

Hi what is the biggest light a noob like me should consider utilizing in regards to the issue at hand? I am considering purchasing the same light but dialed down to 600w

 

[Complete Noob]

Hey Noob. You’re in the same boat as me. So far I can confirm that my ION 315W Cmh and Nanolux DE Chill pass my AM radio test. Neither have any interference unless you stick the antenna within a few inches of the bulb, and even then it’s a very very very faint hum/noise. I can confirm that an older 1k digital se hps ballast FAILED my AM radio test horribly.. this is actually what started my research, discovery and nightmare that is RFI. As soon as the light kicked on the radio started screaming some god awful electronic noise. Unmistakable and literally took over the entire radio frequency band (not gonna name brand names as I’m highly confident no reasonable person would purchase it these day but I had a friend who offered it up so i tried it).

I also have 7’ ceilings. Confident I will be ok with the 1k nanolux de chill with properly training. I think I’m gonna try a gavita this round and see if I can’t get it to work with the low ceilings, if not I am leaning towards replacing the remaining 3 se 1k hps with nanolux de chills.

Rfi is real, but I’ve come to find that there are a handful of lights out there that are properly shielded, etc, and it only takes 1 bad apple to give you nightmares lol. Make sure all your wiring is up to snuff, especially ground loops (there should be none or as few as possible). This will aid in not further transmitting any rfi. I also believe that the “all-in-one” units are the least problematic in terms of rfi. The long wires used to run to your hoods and ballast do no favors in terms of rfi. If you are going to be using remote ballasts be sure to keep all of your ballast and lamp wiring as short as possible. Going to be testing some Rf filters soon as well.

If I were you I would give the Nanolux De Chill a shot. It’s going to be your best bet at utilizing 1k DE with these ceiling heights. Will help reduce a/c needs also.

Thank you I will be looking at that light today. As I stated above I will be probably looking for a 1000w and just dial it down. I will be purchasing this week

 

[PurplePotion]

http://w0qe.com/RF_Interference/grow_light_electronic_ballasts.html

This is the BEST info I have found on creating your own A/C and Lamp side filters. Super informative. Anything else you find on the web will be a watered down version of this. I finally found this after searching for months -_-