The neighbor's electrician came over and after a few minutes of problems
due to a loose SMA connector on my TH-F6, we found there are two problem
lights: one an S3 and one S9+20. Neither was the light I first
suspected, but both were indeed lights.
S9+20 was an SMPS in the ceiling powering a single 12V Halogen light on
a Lutron dimmer. The dimmer is not the problem, and jumpering around it
showed no change. The SMPS is in a metal j-box but is ungrounded and
is run with 2-wire in and sits very near the hot water pipe and several
other conduits, so I asssume that's why the pipes are radiating.
The electrician checked the grounding and bonding of the pipes outside
and said all was to code. He said that in our city, they do not want
the gas line bonded. We verified no other equipment was making RFI
(pool pump, heater, dishwasher, etc.).
The good news is that the electrician plans to replace the in-ceiling
SMPS with a transformer. I showed him a similar LV lighting system I
have (no dimmer though) and how it was 100% quiet with a transformer.
He seemed to think that the "electronic transformer" was superior
because it was quieter, though presumably that's acoustic noise, so
watch out for this tendency if you encounter this situation. He did say
that he used only Lutron dimmers.
The S3 noise is a bank of individually-controlled Juno track lights on
120VAC rails, each an MR16 or MR12 with an internal SMPS. We haven't
digured out a plan for them yet. He seemed to think fixing this problem
was optional, so I showed the electrician (not the homeowner) the ARRL
collection of FCC letters on lighting systems, and told him his first
stop should be the manufacturer. He said he would check with a
colleague who does hi-end audio systems and has some experience for
One last: about 30 minutes after I left, we had the biggest earthquake
in 18 years. I headed back next door with the same HT, now listening to
USGS and individual reports from around the Bay Area instead of a
horrible buzzing sound, and the neighbor said, "I'm sure glad we have
you next door!"
I will report back if the mitigation measures don't work, or if I need
help on them, but other than that, I think we're done here.
On Tue, 30 Oct 2007 3:28 pm, Leigh L Klotz, Jr. wrote:
> Thank you Jim and all.
> The bad news is the neighbor called to say she had not turned off the
> nightlight this morning, so it must be something else. So we are in
> 5% case. Then her electrician called and I am meeting him in about 3
> hours. He thinks it is the heater and is ready to look at bonding. I
> will bring the info from
> Jim K9YC.
> RFI mailing list
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