Ekie xenon sound interference

[Phillip Campey]

Today I took my xenon projector to Peter at the projector trust in Halifax to have it repaired. When I use the magnetic sound there is what I can only describe as radio interference. Typically when we tested it it worked perfectly and made me look stupid, no buzzing, just clear sound. Got it home to test it and the interference is still there. Has anyone had something similar and how can I solve it?

[Nantawat Kittiwarakul]

Maybe of not much help, but is it properly grounded?

[Steve Klare]

Hi Phillip,

It's possible that in the location you are using it, there is some source of electromagnetic interference that the mag head is picking up that doesn't exist at the The Projector Trust.

I'll give you an example I ran into a couple of months ago. There was something interesting about one of my Elmo S8 machines and I decided to look at it with the flashlight on my cellphone. I happened to have the sound on the projector turned up and when I got within maybe two feet, the head picked up a buzz that got worse as I brought the phone closer to the head. (I've been extra careful about laying down my phone near magnetic sound films ever since!)

Another one is there is a ceiling light fixture in the room where my projector table sits. With the audio turned up the lights can be fully on or fully off: no problem. If I use the dimmer for the ceiling fixture? "bzzzzzzzzzz" though the speaker.

We also have lights on a motion sensor out front of our house. If we step out of the car and walk up the front walk, the lights gradually light up so you can see where you are walking. I had no problem with this until I changed the porch lights from incandescents to LEDs. Ever since then if this is turned on and movie audio is turned up, once again: -"bzzzzzzzzzz".

Maybe a good first step is to plug your machine in someplace else and see if the problem stays with the machine or stays in the original place.

[Phillip Campey]

I have tried it in different parts of the house and it still makes the sound, it’s definitely interference of some sort. I’ve ordered a sheeted audio cable and will see if that will sort the problem.

[Steve Klare]

Are you sending the output to an amplifier?

[Phillip Campey]

Hi Steve, no, I’m just going straight from the projector to a large JBL speaker.

[Steve Klare]

The idea that you are having a mag-sound only problem means to me there is a pulsating magnetic field close by. The fact that you are having it everywhere at home makes it sound like you have the pulsating fields everywhere too! (What are your neighbors up to?!!)

-but seriously, do you have any other mag-sound machines at home too? If you do and they don't have this problem, then this is starting to become a puzzle!

[Phillip Campey]

Hi Steve, I have 2 normal 16mm Ekies with mag sound and a Bauer with Mag sound and they are all perfectly fine so I don't know why the xenon is picking up interference?

[Steve Klare]

It’s not unheard of for a Xenon machine to get pickup off its own lamp power supply, but a change in location shouldn’t make any difference.

Unless:

There's this idea called susceptibility where some disturbance on the AC input voltage winds up on the output too. One of the jobs of a power supply is to prevent this.

Example: I have a projection table that has an outlet strip underneath. It's meant for projectors and mixers and disc players (etc.), but it sits next to a table and it's tempting to plug in when doing some kind of work.

Yesterday I was editing a film. I had my editor/viewer on the table and naturally I plugged into the outlet strip. When i finished up, I watched it on a projector. As I ran the film I got "tick!........tick!............tick!.......... tick !............" through the audio. I briefly panicked ("print or machine?!"), but then I unplugged the editor viewer and the audio was fine after that.

There's a certain laptop that I can't leave plugged in while I'm watching films for similar reasons. If I stream video through it, film projector volumes must be set to zero.

Maybe your Xenon power supply has susceptibility issues and there's something else plugged in at home it disagrees with and the noise coming out of it is coupling onto your magnetic sound.

Really good suspects are devices with switching power supplies like computers. One of the problems we run into here is these machines were designed before switchers were really a thing and sometimes they aren't prepared to deal with the noise switching power supplies put on the power lines they are plugged into.

Something with a brushed motor can cause trouble too, especially as the brushes become worn.

If this is the case, the machine should quiet down if you plug in someplace else than home.

[Phillip Campey]

Eureka, thanks for steering me in the right direction Steve and Peter at PP trust, It's the security camera hard drive that is causing it, I switch it off and the noise disappeared. Thanks you for all your help.

[Steve Klare]

So we've reached a time when a projector can be defeated by a camera!

(-strange days!)

[Steve Lee]

It's quite scary when you think about everything we now have in our homes. Everything from wifi, mobile phones, LED lights etc, all giving out frequencies and radiation. In which all of this does not' want to mix with anything analog.
I have a very similar problem to this one.
I love listening to music played back on reel to reel tape. I have many tape copies taken directly from studio masters, I had my deck recapped and calibrated a couple of years ago. So I know it's as good as it is going to get.
Until I switch the lights on.
This is when the buzzing and cracking starts. I have tried everything, from mains filters to surge protectors, nothing will stop it untill I switch the lights off.
I am now confined to sitting in the dark in order to listen to some music. What has this world come to?.

[Brian Fretwell]

Sit in the dark or go back to candles?

[Steve Klare]

There's a lot to be said for sitting in the dark with good music on: either with a glass of wine, or a...close friend, or even both!

[Rob Young]

Reminds me of a time many moons ago when I would run the latest Derann Disney films at my parents house over Christmas. The stereo sound from my Elmo ST1200HD would be booming through the amp in Dolby Surround when, just now and again, and without rhyme or reason there would be a loud "pop" through the speakers.

Over several years of film shows it would do this randomly. Never did it at our place. I put it down to some kind of weird static. Then one year they bought a new oven. Yes, I know...???!!! The random "popping" was all gone...I thought it through and I'm certain it was the old oven thermostat turning the oven heater element on and off being somehow amplified through the mains in the house, with Elmo picking it up!!!