TV Interference with new Icecaps-Help

[fio1022]

Yup

[stugray]

Are you using power strips with built in surge protectors on either the tank or the TVs?

STu

[hahnmeister]

FWIW, in dealing with others that have had this problem, it has been an RF problem like I mentioned before, not something that is being transmitted through the power lines. You can either figure out a way to sheild the ballast, or using a powered antenna seems to do the trick.

At one point, I thought it might be the ballast transmitting through the circuit as well, but when someone solved it with a powered antenna, I figured it was just RF.

Think about it... Icecap will even admit that within a certain distance (something like 15-20ft) these ballasts will cause TV static. Now, if it was something going through the house wiring, you could be more than 20' away, but if on the same circuit, you would still have the problem. Being that its a distance related problem, it has to be RF frequencies, not something coming through the wiring.

Power cleaners, surge protectors w/ power cleaners, ferrite loops, etc... will have little effect. Better sheilded coax cables might though, esp if you have satellite or cable. OTOH, you can sheild the cables all you want, but if you use rabbit-ears, it wont do you any good. You would need a powered antenna, or to sheild the ballast.

The thing is, RF can seem like its coming through the power lines, and may even get picked up in the S-video, and RCA video jacks... even composite. These wires, if not sheilded well, can act as antennae. A ferrite loop works better to cancel out internally occuring static, but if its from the outside, it does little if anything, and can actually make things worse (remember, an AM antenna is a ferrite coil) by acting as an antenna depending on the signals. The RF signals can easily get into a TV or VCR and make it seem like its the power because non-broadcast media will still get static. This is just from poorly sheilded components in the equipment. FWIW, there are computer chips that can pick up digital errors from RF 'spikes', so its easy to imagine the internals on some modern components picking up RF as well. I have Logitech computer speakers that will pick up CB radio if I leave them on after shutting down the computer. Motorolla 68HC11 processors that were used for engine timing in 1979/80 Corvettes later found their way into brake controls for 18-wheeler rigs... and when a police squad would drive by and 'squak', the resulting RF blast would fry a transistor in the chip and the brakes would not work.

Try this: move the ballast beyond 20' from the TV, on the same circuit, and see if it persists. If it stops, then its not in the power lines, its in the air. From past experiences with IC ballasts (and the two I have), this tends to be the case.

Another option would be to house the ballast in something like a thick aluminum&copper casing that would block the signals. I havent messed around with it too much, but it might be as simple as wrapping the ballast in a few layers of foil.

[BeanAnimal]

Hahn....

I have to disagree with you on this... You kind of all over the map with your explanations and terminology. Not trying to pick a fight, but you know how I am about details.

Yes poor shielding can be a problem, as can high energy RF. I can talk over the local MALLS PA system or fry your car radio with a suitable high gain CB amp just by keying the mike within 20 yards of said equipment.

There are a few things to consider here.

1) RF interference emissions through the case being picked up by the shield on the TV cable. (this is party what you are talking about). We can fix this in several ways. Methods (as already mentioned) would be to move the ballasts or other wires so that they do NOT inject signal into house wiring. We cna use ground isolation to drain the signal to ground and keep it from coupling with the TV equipment. Note that the ferrite loops and power cleaners are still needed. If the signal is strong enough to JUMP to the cable shield it is also strong enough to jump to the power supply feed. We want to filter it before it travels back to the power distribution point.

2) RF or HF tranmission through the power supplies being picked up by the power cables. Self explanatory. We want to filer the power supply line feeding the unit.

Saying that a ferrite loop will make matters worse is somewhat silly. If the unit is emitting that much RFI, then the using the ferrite beads/loops is a must to keep that same signal from being inject into the supply source.

You are correct in infering that once a signal is injected, it is hard to filter out. This is almost impossible if the injected signal is within the pass band of the GOOD signal.

Also, wrapping something in tinfoil is not going to help. The case is already METAL. You are on the right track... but the "cage" needs to be isolated from the equipment. You are thinking of a "Faraday Cage"... But alas, IceCap and others must meet minimum standards for RFI and part of the design is that metal case acting as a Faraday shield. Placing the ballasts in a metal container will help, but the vent holes must be smaller than the wavelength of the transmission... in this case that may be rather hard.

That leaves us with trying to keep vulnerable sources away from the ballast, and cross them at right angles to the transmission path.

The steps for isolation and correction are fairly straight forward. In this case, lifting the ground on the entire cable TV system will likely fix the problem (and introduce a safety issue). Lifting the ground would be my next logical step.

CATV ground isolation transformers can be used at the equipment side while leaving the headend ground (for safety).


http://www.siber-sonic.com/electronics/GLoopFix.html

Off to work... Enjoy the day folks.

[hahnmeister]

Im just saying what I know works in this case. Your broad application of knowlege, although true, isnt needed for this. I have seen what the problems tend to be (I have been where you are now, and tried the various methods, and found out what works). At that, I dont think we really disagree on anything...

Your first point, well, I dont think I have to go into, because from past experience, the interference isnt coming through the wiring. If this were the case, the ballast could be more than 20-30' away, and still cause problems because all that would matter would be the wiring. Im tellin' ya, the most common solution for this is a power antenna (perhaps for cable, a signal booster?). Your second point as well... well... I just dont think its needed because I dont think its anything but RF in the air.

And yes, ferrite loops can make the problem worse. Ferrite loops are also antennas.

As for the metal box, icecaps do meet the minimum, but you might be shocked as to how lax that standard is. Even computer cases 'pass' despite giving off loads. You dont even need vent holes on an icecap.

As for the rest... try moving the ballast while plugged in to a more distant location... and see what happens. From what I have seen, its purely in the air, not the wires.

[a1amap]

Originally posted by fio1022
Could you explain this.I'm pretty green when it comes to electronics.I know the basics.Never heard of a ferrite filter.

Here is an example of one http://www.radioshack.com/product/in...entPage=search

[BeanAnimal]

Hahn... if it is in the air, then it is in the wires The fact that it is on ALL of the TVs would indicate that the shield is likely picking up the signal and injecting it into the tuners.

In any case a very quick and methodical look at the situation will yield the answer.

As for the ferrite loops making things worse... sorry Hahn, but that is a stretch. We are talking about 1 or two turns of wire on a small core. Please don't make me get out the math to show you why they work like they do, and why an antenna has more turns and a larger loop or a rod. We can talk all day long about inductors and why and how they work. Adding a ferrite bead or small loop to a power cord is not going to make the problem worse If it DOES, then we have much larger problems!

[BeanAnimal]

http://64.70.157.146/archive/keithar...chniques3.html

That will get you started... Remember our concern is what would be in-band to the TV tuner and eliminating it before it reaches the inputs.

[hahnmeister]

Its not such a stretch... its not likely that it would make it worse, but I doubt that the loop would do much anyways to improve things considering the range of signals that are causing the problem. Thats really why there is just more of a chance of making things worse... its not so much the likelyhood of picking up new signals, but the likelyhood of not doing much for the interreffence. Been there, tried that.

There is actually a thread that was here only a couple months ago that I was part of... same problem. A signal booster/power antenna was all that was needed. Either that, or move the ballast away. At that, I dont think there is much in the way of noise coming through the power still. Normally I would agree Bean... if its in the air, its in the wires, but even the crudest of home electronics have filters that should be enough to deal with these problems that dirty up the components. There is a larger possibility that something in the components is not sheilded well enough, and this could be it. This is likely. I have noticed with my Icecaps that as soon as I go beyond 20' from the TV, the problems stop. I also dont have problems with the DVD or VCR making noise... but I am using high-end stuff that has sheilding in it. I tried some of those crappy RCA connectors, and sure enough, I saw some banding. Otherwise, I use higher-end sheilded cables to go from the VCR/DVD/TV. I dont have cable (no time), so my only method of testing is with the digital and analog antenna. A powered antenna goes a long way here. I would imagine, for cable/sat TV, a signal booster might be the best method.

But really, if it were coming through the power lines, then the whole distance thing wouldnt be true. You could have the ballast and TV on the same wiring at opposite ends of the house, and you would still have problems as long as they were on the same circuit. I havent found this to be the case.

[BeanAnimal]

Hahn lets make this simple.

Your CABLE TV TUNER has band pass filters in it to eliminate unwanted (out of band) signals. If the BALLAST is producing interference IN BAND, then the on board filters WILL DO NOTHING to attenuate the signal. What don't you get about that? We use the ferrite loops and other techniques to eliminate the IN BAND interference before it gets injected.

The key point... The ONLY way to stop those problem signals is to eliminate them before the get injected into the POWER or SIGNAL path.

That is why filtering the BALLAST power supply is so important. That is why isolating or filtering the ground is so important (when problems like this crop up). The foil and braid on the coax is allowing the signal to be injected into the equipment. We need to stop the signal from being injected into the COAX and POWER cords hahn. What is so complicated about that?

Distance STILL plays a role. Wire (power or coax) has a resistance and a capacitance. The ballast EMI, RFI that is injected must travel down those wires. The longer the run, the more the signal is attenuated and the less of a problem it is. The further the BALLAST is away from the signal path, the less of a problem it is.

Is the BALLAST itself capable of emitting interference over the air and injecting it directly into the TV equipment? Of course. That my friend is NOT the only problem. You keep talking about "been there tried that" but given you "explanations" of the science here... Well frankly, your off base. Of course better shielded cables may help. The problem is the quality of the ground and the preseesne or absence of ground loops and other 60 cycle noise.

I can show you banding, 60 cycle bars, EMI and/or RFI problems using fully shielded equipment with mega dollar cabling.

Can we burry this silly arguement before it gets out of hand?

[fio1022]

All I can say is I ordered the loops and I'm crossing my fingers.Can't relocate ballasts.Even if I could,anywhere i put them would be within 20 ft of a tv.Small house...
Don't these ballast need to be
somewhat close to bulbs?

[oldschooldino]

First to fio1022, I don't currently have this problem, but will be upgrading my lights soon. Good luck, I hope you all get it sorted out. Second, to hahnmeister and beananimal: I love reading threads where you guys "discuss" things. It's always informative and entertaining, even though the "discussion" usually goes over my head very quickly

[hahnmeister]

Bean, rather than questioning why I dont get something in that tone you take, stop and remember, the whole point I was making was that I dont think these signals are coming from interference IN BAND like you say. Why cant you get that?

At one time, I thought it might be IN BAND as well, but I was wrong. You asked "Is the BALLAST itself capable of emitting interference over the air and injecting it directly into the TV equipment? Of course." and then went on to say that this is not the only problem. But Im telling you, it IS THE ONLY PROBLEM. Im not off base. I dont care about what you want to argue. I had a similar problem, and known others that have as well, and the solution was a simple powered antenna. What, do I need to take pictures of my stupid ballast and antenna to prove this to you or something. Im telling you 'been there, done that' because I have had the problem, and I know how to solve it... as well as others. I tried a loop and then a power cleaner, and they did jack. Im not 'off base' here. Do you have an icecap ballast? Have you had to deal with this problem ever? Did you solve it?

[hahnmeister]

Hey, I have the ultimate solution!!! Ditch the icecaps and use M80 ballasts! Thats what I ended up doing a while ago on another tank.

Also, I forgot to mention... quad shielded coax seems to solve the problem for people as well. This doesnt help if you are using RCA/component/S-video cables, or if your actual components are poorly sheilded.

Otherwise, a Shielding Plate/Box for the offending device. I used a power cleaner once on mine... didnt solve the problem.

[stugray]

Lets put the whole conversation in perspective for the ones that care to follow along:

Electromagnetic Interference / Electromagnetic compatibility usually takes the acronym of EMI/EMC.

An EMI/EMC engineer concerns himself with BOTH Compatibility & Interference.

When one designs and electronic component, it must meet requirements imposed by the FCC for a number of 'attributes' of the devce.

The device SHALL OUTPUT less than a specified amount of energy by radiation and by conduction. These are the Radiation Emissions and the Conducted Emissions ( known as RE & CE ).

These devices also:SHALL NOT be affected by a certain amount of energy by radiated or conducted means. These are Radiated Susceptibility & Conducted susceptibility ( known as RS & CS ).

The devices like our TVs, DVDs, and Home entertainment Amps have been tested to meet FCC requirements for RS, CS, RE, & CE.

If we place one device into our homes, and it causes problems with all of our other devices, then it:

1 - Never met the FCC requirements in the first place, and the design is flawed.

OR

2 - The device has had a failure ( probably in the Power Input filtering circuit ) and is now considered defective.

So... since I have had an Icecap 660 less than 5 feet from my home entertainment center with no issues, I can only conculde that it is a problem with the setup, and NOT a problem with the design of the Icecap.

With that being said, the problem must be:

1 - the User has a unique problem with his entertainment unit ( unshielded wires, faulty input filtering, or bad grounds )

OR

2 - His particular Icecap has a problem.

Some of the suggestions above can be used to diagnose the problem and some are purely conjecture. Now that we have proper terminology in place we can discuss the problem more efficeintly.

You want to determine if the problem is coming through the power lines, or being transmitted?
Use an UPS, or generator on the receiver box ( even an extension cord to the neighbors house would work, provided he doesnt have the same symptoms ). It would be ??? if you could run a TV on an UPS unless you got a big one.

Stu

[BeanAnimal]

Originally posted by hahnmeister
the whole point I was making was that I dont think these signals are coming from interference IN BAND like you say. Why cant you get that?

Hahn, if it is injected into the amplifier and displayed in the screen, then it is IN BAND. It is either in the power circuit or the video display input. Pretty simple, but something you are not seeing. It "gets into" the equipment or the wiring be either conduction or radiation. You are not understanding that the RADIATION will (can) affect the cabling and force it to act as a conduit for the interference.

Part of the fix (as you understand) is to MOVE the equipment and BOOST the desired signal in relation to the undesired signal. This hahn is what we would call signal to noise. Boost the SNR and hope that the problem is hidden.

The part of the fix that you ARE NOT understanding is dealing with the OTHER part of the problem. We want to remove the IN BAND interference BEFORE it travels into the signal path. This is where the power filters, ferrite loops, isolated grounds, etc come into play. PERIOD.

At one time, I thought it might be IN BAND as well, but I was wrong. You asked "Is the BALLAST itself capable of emitting interference over the air and injecting it directly into the TV equipment? Of course." and then went on to say that this is not the only problem. But Im telling you, it IS THE ONLY PROBLEM. Im not off base.

No hahn, you just don't understand the whole problem. That is what I am trying to show you. You speak with authority on this subject but it is very obvious that you have some fairly significant gaps in understanding and logic.

I dont care about what you want to argue. I had a similar problem, and known others that have as well, and the solution was a simple powered antenna.

Very few of us watch over the air broadcasts hahn Yes raising the SNR may fix some problems, not all problems.

What, do I need to take pictures of my stupid ballast and antenna to prove this to you or something. Im telling you 'been there, done that' because I have had the problem, and I know how to solve it... as well as others.

You may have solved YOUR problem. That still does not mean you understand the real issue and it certainly does not mean that your solution will work in ANY percentage of cases. Your missing some very basic understanding here. I am not being mean, just stating the obvious. And no, I don't care to see a photo of your ballast and amplifier.

I tried a loop and then a power cleaner, and they did jack. Im not 'off base' here. Do you have an icecap ballast? Have you had to deal with this problem ever? Did you solve it?

And there comes the straw arguments. Shall we all own something to be able to talk about them? IceCap Ballast, Arc Welder, Tesla Coil, kilowatt amplifiers, tube amps, tube preamps, huge gensets, huge UPS systems, etc.... you name it hahn, and I play with it. High end audio and home theater are passions of mine and electronics design and construction has been a life long hobby. I work (as part of my business) with voice, data, and multimedia cabling on a daily basis. I spend a LOT of time with engineers in the field. I know a little bit about this subject.

Could you be 100% correct in your method of fixing the problem? Of course. I explained this in the last post as well. That still does not mean that YOUR logic or understanding of the problem are sound. Your a smart guy, but have a tendency to "fill in the gaps" with stuff that just isn't there

[hahnmeister]

I never filled in any gaps, Im just posting what has worked for me and many others. do a search on it here at RC, and you will see its a subject that has been covered many times.

[reznor252]

How about a cable guys opinion? I have to deal with issues like this on a daily basis. First off it is entirely possible to induce noise on your house wiring due to an improper house ground. It is also possible for the ballast to "transmit" the noise directly into the coax but due to the fact it does it on the dvd player this seems to disprove this for now but it could be multiple problems.

fio1022, can you explain what the interference looks like on the tv? Is it a rolling horizontal bar from bottom to top? Is it wavy distortion throughout the who screen? How many cable outlets do you have active in the house? Do you have any issues with lights dimming when ever high current items come on such as an AC unit or your washer/dryer?

If it is being transmitted through the house ground one thing you might want to try is unhooking the ground from the ground block where the cable goes into your house and see if it goes away. This will be where it interfaces with your house via aerial cable or underground cable and usually by the power meter on the side of your house.

[fio1022]

I tried disconnecting ground at block,which is grounded at water pipe with phone, no difference.
It is two faint but distinct horizonal bars that roll up screen.Much more pronounced on lower channels(2,4,5)with roof antenna.Not as strong with sattelite.

[reznor252]

Is your power aerial or underground? It is common to see rolling hum bars in aerial power scenarios due to a floating ground/ bad neutral. Most water pipes are grounded so the excess electrons will pull from that ground source if the house ground cannot supply enough, however, I am at a loss since the hum bars did not go away when you disconnected the ground. One possible way to determine if it is inside wiring or a ground issue you can run an extention cord of appropriate gauge for your application (ballast) to a power outlet across the house to a different breaker and see if the problem still occurs. If it does I would call your electric company to have them check their connections at the weatherhead assuming it is aerial.

[fio1022]

Well I checked the house ground at the water main and it doesn't look all that good.I'll have to change that out.Neutral in panel looks OK and is tight.I'll check meter pan and weatherhead tomorrow.Being that I work for the local utility, it shouldn't be a problem.

[fio1022]

Ferrite loops didn't do a thing.
I contacted IceCap direct and told them my problem.He didn't think the ballast was the problem but I insisted that it was.They wound up sending me one of the new style ballasts to try out and see if it would eliminate problem.It did!I sent back second ballast for replacement and static interference is totally gone.
New ballasts are a much nicer improvement over old.Built in heat sink,power cord and zero interference.

[BeanAnimal]

The rolling horizontal bars were 60 cycle hum bars and due to the power supply in the ballasts injecting the hum into the power system if your home. The root problem may have been the ballasts, but could still be grounding problems at your home