On Tue, 22 Sep 2009, Paul wrote:
> For the past six months I've been putting up with S9 noise on 17 & 15
> meters. On the 7800 scope it's just solid green, no pattern in it.
> Doesn't look like it's going to fix itself so took portable SW receiver
> out and found the source - where the underground phone lines come up to
> a terminal box where the lines to the houses connect, there is a good
> signal, loud with the receiver antenna collapsed.
>
> An Embarq tech was here today cleaning the batteries in the remote
> switch (and fiber to wire interface) - with the doors open there are
> several areas in the switch that are really noisy, but not too bad when
> the doors are closed.
>
> I'm guessing that noise is being coupled to the underground cable - any
> ideas of what to tell them to do to fix this? Maybe a bad ground, or
> put toroids on the cables?
>
> Thanks
>
> Paul W2LE
Based on the description I am guessing this is a full on powered remote,
the ones my employer uses are commonly 8ft wide, 6ft tall and 4ft deep
with locking doors on all sides. They can also be much smaller or larger.
(Small might be 2 deep cycle batteries and a single 512 line combined
voice/DSL over fiber backhaul endpoint, large might be that and more for
thousands of line with a build in generator)
An a minimum there will be an AC power feed into a battery charger, this
could be a classic transformer based "rectifier" (-48VDC supply/float
charger), or more likely a newer unit that is actually a switching
PS/charger. There will be a -48VDC batt bank, prolly hi-cap deep cycle
AGM.
>From there the possibilities are many as to what is in there, commonly
found these days are VOIP or classic fiber circuit backhaul voice
platforms, ethernet switches, DSLAMs, SONET terminals, or devices that
combine more than one of these functions. Most of these would be FCC
class A devices and contain switching power supplies.
I would file a complaint with the company, and be prepared to explain the
issue many times. Don't be surprised if you need to fall back on
registered letters copied to both the company and the FCC.
I would also note that this is *not* an easy situation for them, it could
be any one of many devices (or even multiple devices), and debugging by
powerdown could be an issue... This type of cabinet could service a whole
subdivision for voice/DSL (up to 5,000 subscribers is not a stretch here),
but there could also be transport equipment present acting as wider area
transport for tens of thousands of customers.
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