VO-BB - 20 YEARS OLD!

[JTVG]

Sorry for the long post.

The strangest thing happened today. I'm about 5 minutes into a phone patch and all of a sudden, audio interference. (Hear mp3) At first I thought it was another phone conversation bleeding in, but it appears to be a local AM radio station (880, WRFD). To try to get rid of this, producer hangs up to call me back. But before he does. I engage the phone patch just to see if the audio was still there. I hear the customary dial tone and yes, the interference on top of it. Again, I drop the line. A second later the producer rings in, I hit "on" and the problem audio is gone. But five minutes later, it comes back. We drop the line, he calls back, no interference. It's like a reset. We did this four or five times. I just tried it myself (calling in with my cell) and same deal, about 5 minutes in, a loud pop and then interference.

DETAILS:
Phone cable is wye'd coming from the jack using an adapter. One line breaks off for the fax machine, other goes to the Genter Digital Hybrid 2. Unplugging the line to the fax, either at the adapter or the fax machine kills the interference. Well, it's still there but so quiet it would never be an issue. You can hear on the mp3 how it "pops" in and then I unplug that line to the fax. We have a digital phone line (AT&T Uverse) if that matters at all.

This has never been an issue before this week. We had electrical circuits added last week and some rewiring done so if I had to guess at a cause... however, the fact that it's always clear for 5 minutes when someone calls in and then the problem starts has me completely puzzled. Equipment around the Gentner has been turned off and on to no success, including the fax machine.

Ever come across anything like this before?
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Joe Szymanski
http://www.joethevoiceguy.com

[CurtZHP]

Go to Radio Shack and look for ferrite cores. Buy several. Place them on the phone cords. That might help. If it's coming from a local radio station, by all means call the station and ask for their Chief Engineer. They should be more than happy to help. At least they had better be! I work in engineering at an FM station, and I can attest to the fact that when someone calls us about our signal showing up in places where it oughtn't, we jump.

Actually, come to think of it, call the station before you buy anything from Radio Shack. If the problem is RF interference from the radio station, they may be obligated to pay for any fixes. (Don't panic. Ferrites are cheap.)

[CurtZHP]

How old is the Gentner? The fact that the problem shows up after a given amount of "on" time could mean that a filter or power supply capacitor in there is starting to show its age.

[Hart]

Joe,

If I was a betting man I'd say it has something to do with that new wiring and a poor ground somewhere. Can you plug the Gentner into a different power circuit and see if it makes a difference?

I was going to suggest the same things curt has on the ferrite cores too so there's a start.

Also double check and make sure you aren't using any unbalanced cables to connect anything. I had a similar problem once upon a time after I had moved a tuner. Why moving it two feet made an AM station bleed into my telos unit I have no idea. Anyway I swapped from an unbalanced 1/4 cable to a balanced one and it fixed it.

On your phone lines - do you have to use those filters like you'd put on with DSL? If so it could be that it's going bad. That happens pretty often. EDIT: PS I've never heard of THAT happening because a filter went bad but it's something else to check.

It is puzzling that it comes in after 5 minutes. Weird. Anyway hope something helps.
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Hart Voice Overs Blog
Brian Hart Productions

[JTVG]

Thanks for the suggestions, guys. No filter has been needed for UVerse as far as I know. I believe the cables are balanced, at least they show a tip-ring-sleeve configurement and not just tip-sleeve. Replacing them would be difficult since they are wired into the unit thanks to the radio station I got it from. On that note, this unit is ancient. Not sure how old, but my guess would 80s to early 90s. Here's a pic of one.

I'm thinking I'll try the ferrite cores first. It's nice that I can simply unplug the fax for a quick fix but it would be great to find a cure.
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Joe Szymanski
http://www.joethevoiceguy.com

[kgenus]

I'd put my money on the cure being that station's overworked, underpaid engineer.
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Genus

[schrecster]

so do you think your equipment is acting like an antenna and picking up the radio signal, or is the problem in your phone line at the central office or between the central office and your demarc? by that I mean is the problem with the phone company. I have always found that cross talk problems are in the phone company's equipment.

You would think any of the studio equipment you have would be shielded and protected from acting like an antenna and picking up interference.

you may want to call your local provider and open a ticket with them and have them test the line. also if you tell them what you are using the telephone lines for and that you need a nice clean signal, they may be able to provide you with a pair that is less noisy and has a better signal. who knows, the phone company may have done some regrooming inside their office and you have been moved to a different circuit all together and this new circuit is noisy.

[JTVG]

I suppose that's also possible. I could troubleshoot this another 2 or 3 ways but just haven't had the time. The next test would probably be plugging the phone directly into the wall jack and bypassing the patch box to make sure it isn't a line problem. I also need to check it again with the fax line plugged in to see if it was some strange atmospheric thing yesterday. And a call to the Chief Engineer at the station is probably a good thing if the problem persists.

Thanks!
_________________
Joe Szymanski
http://www.joethevoiceguy.com

[JTVG]

Update:
The problem doesn't seem to be the Gentner. I plugged my handset into the Y adapter coming off of the wall and heard a little bit of the interference audio. Not as loud as before though. Didn't seem to hear it when I bypassed the adapter and plugged straight into the wall. Maybe that adapter or something related to the fax line or fax machine is the culprit, combined with the new wiring.

Funny, I just hooked everything back up properly now and there is no interference at all. Maybe I messed with it enough to get the troubles out.
_________________
Joe Szymanski
http://www.joethevoiceguy.com

[CurtZHP]

New electrical wiring doesn't seem likely to me if it's picking up a radio station. The most common AC wiring problem is poor or no grounding which would most likely manifest itself as hum. Something in the system (and it looks like either the splitter or the fax) is acting as an antenna.

Does the fax machine have a phone handset? Can you plug in just the fax machine and listen for interference?

[JTVG]

I think we can now rule out the fax too. Just now, the interference popped in at about 8 or 9 minutes into the call and unplugging the fax from the adapter did nothing, surprisingly. I'm testing a bypass of the adapter and going directly into the wall jack now with the Gentner.

UPDATE:
15 minutes in and interference just popped in. Hmm. Only way to test now is to plug the cordless system directly into wall jack and bypass the phone patch.

UPDATE 2:
I'm hearing very quiet interference right off the bat right now with the cordless handbase directly plugged into the wall. So, the line itself is the problem I guess. I called the wrong AT&T number to get a ticket and it popped in loud again but it didn't during the 2nd call.

AT&T is set to come out tomorrow morning. They said they can put a filter on the line, among other things and they did register a little bit of packet loss during the test.
_________________
Joe Szymanski
http://www.joethevoiceguy.com

[Gregory Best]

I had fun when they relocated KCBQ (50kw AM) to piggy back on some towers I can see from the top of my road. Couldn't hear phone conversations. Cox cable our digital phone provider brought some filters that reduced the sound, but it was still noticably there. We have a cordless 4-line business phone system.

Called the Chief Eng. who mailed me some good filters that killed the signal's interferrence. He offered to come out and help and was really interested when I told him of my days in radio and now in VO.

[edited for typo]
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Gregory Best

greg@gregorybest.com

[CurtZHP]

Fact is engineers are required to investigate (and if necessary, fix) any interference complaints. That's the responsibility of the licensee.

[JTVG]

This is getting tough to figure out. Tech was here, said he tapped in at the phone box and heard the problem, disconnected an old drop that was not being used that he claimed was acting as an antennae and that according to him, fixed the problem. He also installed some filters. I listened briefly on my handset and didn't hear anything so figured we were good. 10 minutes after, when testing the Gentner, it was back again. It even popped in loud during my phone call to the tech who had just left a few minutes prior so he heard but didn't have any insight other than to say the problem is on the inside wiring somewhere because he didn't hear it at the phone box outside any more.

So, I tried bypassing the Gentner and going right into the adapter that has the fax line also connected. Still there. Disconnect the fax line. Gone. Ok, must be the fax line again. Can't be the Gentner. No interference when the adapter is bypassed and the Gentner is plugged directly to the wall jack.

I have a call into someone at WRFD who will hopefully put me in touch with their Chief Engineer who freelances for the station. Maybe he'll have some insight.
_________________
Joe Szymanski
http://www.joethevoiceguy.com