Re: X-10 RF home automation being overwhelmed by M2 OFF, C2 OFF and Gxx DIM signals

[jamesgangnc <jamesgangnc@xxxxxxxxx>]

On Aug 30, 10:57=A0am, bud-- <remove.budn...@xxxxxxx> wrote:
> On 8/29/2011 8:48 PM, The Daring Dufas wrote:
>
>
>
>
>
> > On 8/29/2011 3:01 PM, Robert Green wrote:
> >> "The Daring Dufas"<the-daring-du...@xxxxxxxxxx> wrote in message
> >>news:j3gi0g$89e$1@xxxxxxxxxxxxxxxx
>
> >> <stuff snipped>
>
> >>> Back in the late 1980's I was working and living in the country of
> >>> Californiastan when the community I was in at the time started having
> >>> problems with their electric garage doors opening and closing as if
> >>> possessed by some evil door opener. It turned out that the US Navy
> >>> was testing the big search radars on some ships in the bay. Those big
> >>> powerful radars were producing an RF harmonic signal that was just ri=
ght
> >>> to screw with the RF remote controls for a lot of openers. :-)
>
> >> Yes, I was aware of them. Lutron's Radio RA system had to add a second=
 RF
> >> channel in NYC because of interference from a source that wasn't going
> >> away.
> >> Read: government.
>
> >> We just had a round of that a few years ago near DC at Andrews AFB and
> >> others in Denver had the same problem. I know that two military resear=
ch
> >> labs nearby (I live between the two on almost a perfect straight line =
are
> >> tasked with IED jammer development so I wouldn't be surprised if the
> >> signal
> >> correlated with elevated threat levels. The DC area is as the Pentagon
> >> says
> >> "target rich environment."
>
> >> But in reality I think Dave is probably onto the real source: The loca=
l
> >> power company has just instituted a program where they hook a
> >> receiver/relay
> >> between your AC and the powerline. In brownouts, they can shut your AC
> >> off
> >> remotely. I was going to apply for it because we don't use our CAC
> >> anymore
> >> and have switched to window ACs, but that seemed to be cheating so I
> >> decided
> >> not to.
>
> >> The "blips" started appearing a month or two ago, when summer began. T=
hey
> >> are not there today, with the temps in the cool, dry 70's (the benefit
> >> of a
> >> hurricane - wonderful, cool, clean air for a day or afterwards). Now I
> >> have
> >> to download some temperature data and try to correlate that with the
> >> times
> >> the bogies appear in my Homevision log file (records all externally
> >> generated commands to log file). The days of endless bogies generate h=
uge
> >> log files, 100 to 1000 times the normal size.
>
> >> --
> >> Bobby G.
>
> > I'm an old broadcast engineer/two way radio tech and I had to track dow=
n
> > RF interference all the time. My friend who worked for the local
> > power company as an electrical engineer in charge of their
> > communications told me that back in the 1970's they were tracking down
> > a lot of RF interference caused by doorbell transformers. I have an
> > idea that today's proliferation of "Wall Warts" could be responsible
> > for a lot of RF and power line borne interference. It's something to
> > consider.
>
> Doorbell transformers sound really bizarre as a source of RF. Somebody
> at a.h.r tracked down a source that says it is from contacts that
> disconnect the transformer when the current is too high for a class 2
> (limited energy) transformer. (Or something like that.) Contacts would
> repeatedly open (with arcing) and close.
>
> My guess is that class 2 AC-out wall warts are "impedance protected",
> which most doorbell transformers probably are now. At too high a current
> the voltage just droops.
>
> My guess is that DC wall warts are the same, or the DC side has a
> current limit circuit. Are they switch-mode these days? Wouldn't think
> switch-mode would be worse than other switch-mode power supplies found
> all over the place.- Hide quoted text -
>
> - Show quoted text -

The transistion from transformer to switched has mostly happened but
there are a lot of existing transformer ones floating around still in
use. I like the switched ones because most work on anything from 100
to 240vac.  Sure makes travel easier.