Re: Need help with PLC noise problems in a Manhattan (New York City) apartment

[ddl@danlan.*com (Dan Lanciani)]

In article <43a21592.5985976@xxxxxxxxxxxxx>, nobody@xxxxxxxxxxxx (Dave Houston) writes:

| I'm also a bit puzzled by how the 6825 works. It would really help to see a
| schematic.

I don't believe there is a 6825, but the 6285 (which I think is the one
being discussed) is very simple.  It has two 1uF capacitors (each with
a small protective(?) series resistor), one from each line to neutral.

|The effects of a signal sink are somewhat localized because of
|the impedance of the wiring itself but I don't quite understand how a 6825
|can attenuate alien signals without also attenuating legitimate signals
|trying to go from 2B to 2C.

It can't.

Something I always thought would be neat (and I proposed this to ACT) is
a repeater that bridges a low-impedance onto the line during the transmission
of a "0" (rather than doing nothing).  This would provide an active solution
to noise problems.  When my last CR230 failed with the dead high-voltage power
supply it managed to block transmissions rather than repeat them, so it might
not even require significant changes to the design.  (I.e., a good coupling
network for 120kHz probably also makes a good sink if shorted rather than
driven.)

				Dan Lanciani
				ddl@danlan.*com