Electrical question?

[planejane]

My Vortech MP10 is causing interference on my TV's ( 2 different ones on different circuts), makes white diagonal lines across the screen. I have comcast cable , and it only happens on the lower numbered channels. I've email:hmm2:ed Echotec and Steve's reply was he never heard of such a thing. I'm sure it's the pump because it stops when the pump is unplugged. :idea:

 

[EvilMel]

bizarre

 

[planejane]

bizarre

And annoying!

 

[trbike24]

Hey Janie, this is Trent from Aquatic Marine. I was talking to Mark about it and he said it was an electrical harmonic imbalance. If you want to gives us a call, he will help you.

 

[planejane]

Thanks trent.

 

[cee]

Questions:
1)Are the TVs on the same circuit breaker as the pump?
2)Do you use a converter box or does the cable go straight into the TV? If a converter box, is it on the same circuit as the TV?
3)Does the amount of interference change with the pump speed or is it constant?
4)Is the interference present even when the pump is off if it is plugged into the circuit (this question may reveal the fact that I've never owned a Vortech)?
5)How close is the pump to the TV(s)?
Your answers will help diagnose the problem.

 

[planejane]

Questions:
1)Are the TVs on the same circuit breaker as the pump?
2)Do you use a converter box or does the cable go straight into the TV? If a converter box, is it on the same circuit as the TV?
3)Does the amount of interference change with the pump speed or is it constant?
4)Is the interference present even when the pump is off if it is plugged into the circuit (this question may reveal the fact that I've never owned a Vortech)?
5)How close is the pump to the TV(s)?
Your answers will help diagnose the problem.

Dave,

1) NO
2) No converter box
3) No, it's constant
4) Yep, your lack of Vortecese is showing! Theres not On/Off switch. You can unplug the driver from it's power supply box, the interference goes away doing this (leaving thepower supply plugged in).
5) One Tv is 3 feet away the other is in another room 25ish feet away.

Thanks

 

[NanoKeepr]

There was a recent issue of the same TV interference from an MP10 on another forum. It was resolved by exchanging the unit for another MP10 and no more interference! One of the folks in the forum thought the explanation might be "probably the rectifer in the power supply. They usually work fine but if one of the diodes are not working, they tend put out RFI."

 

[planejane]

There was a recent issue of the same TV interference from an MP10 on another forum. It was resolved by exchanging the unit for another MP10 and no more interference! One of the folks in the forum thought the explanation might be "probably the rectifer in the power supply. They usually work fine but if one of the diodes are not working, they tend put out RFI."

That's interesting, because Steve from Echotec said NO one else has ever had this problem and insists it's a fault of my house wires and to go to radio shack and see if they have some sort of filter to put on the TV.

 

[Runner]

It sounds like the rectifier on your AC to DC converter (I assume the Vortech is low voltage DC?) is causing a noise problem. Certain filters on the TV circuit would help isolate the TV from this problem. But I'd bet the real problem is one of two things: either the rectifier has a bad diode (or broken wire on one of the diodes) as mentioned above, or there is something wrong with the ground/neutral in your main panelboard. If it was the latter, though, you'd likely get a similar problem every time you turn on your computer or washing machine. If you weren't clear on the other side of town, I'd offer to make a quick stop by to check out the electrical.

 

[cee]

I'd guess the converter is generating high frequency noise that is showing up on the video signal since she's only seeing it on the low (= low frequency) channels. I don't think an unbalanced rectifier would cause a big enough line dip at the low wattage that her power supply is putting out. Only way to know for sure is put a scope on her AC line and look.

 

[Runner]

Makes sense, but the most likely thing that could be causing this is something bad in the rectifier circuitry -- perhaps even a capacitor gone bad and making the waveform get all screwy. I would think that would affect pump performance more than the harmonic content or noise on the line side. If it was a problem on the TV side, I would think the PC would be having a negative impact as well.

Easiest way (that doesn't involve an electrician and $$$) to narrow down this problem further is to borrow a Vortech from somebody and see if it replicates the problem.

 

[cee]

Cable modulates a few megahertz around the carrier frequency which starts around 55 megahertz. The converter probably operates around a few megahertz, hence my assessment.