 |
 |
I wonder if it's a command or telemetry carrier inserted to run the HVAC? Would have to be a pretty hefty carrier, methinks. If so, a Line Conditioner may not be of help. But you also mentioned the "stringing of some sort of digital cable". It might be time to involve the I-T folks... Regards, Mark Durenberger -------------------------------------------------- From: "Martin Fisher" <[log in to unmask]> Sent: Tuesday, August 30, 2011 1:07 PM To: <[log in to unmask]> Subject: [ARSCLIST] FW: Another AC outlet noise problem > Hi gang, > > FYI, the following is cross posted to two list serves. > > A mysterious squeal appeared in the transfer chain here in the audio lab > about two months ago. It's a tone centered around 10,330 hz and seems to > be coming in on the AC power lines for a good portion of the building. > This has been determined by taking a piece of equipment (in this case a > Soundesign 8 track deck with integrated amplifier and a pair of > headphones) and plugging into several outlets in the building. The tech > power outlets for the recording studios are clean as well as some outlets > on the 2nd floor but many of the 1st floor outlets have the offending tone > present. > > I've tried isolation transformers and low cost IsoBar type line > conditioners with absolutely no luck. The tone appeared at approximately > the same time of a revamping of the air conditioning system for the > building and stringing of lines for some sort of digital cable. One of > the campus electricians did some switching around of breakers and various > things but nothing has helped. Before I go out and get a high end line > conditioner to try out I thought I'd tap the collective wisdom of two of > the best informed list serves. Any ideas?? I'm sure I've not provided > the best description in the world so I'll try to answer any questions that > arise. > > Thanks. :-) > > Martin