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...
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
> 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
> Thanks. :-)