Re: XTB - the Future of X10 has arrived!

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message

> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:
>
<stuff snipped>

> It could even mean 2004. I believe the CM11A was introduced in 1997
although
> it may have been in beta testing a year earlier. Where did you park your
> tardis in 1985?

My bad!  I used my X-10 database instead of going back up the stairs to the
attic to look at the actual CM11A.  The real date code is 7C11.  One day I
decided to enter all my X-10 gear into a database and had a tendency to
overuse "set carry on" to deal with repeating data.  As near as I can tell,
it got swapped with an RR501's date code and revision number.  The CM11A has
no revision number or if it did, it's fallen off.  I bought the 4 button
belt-clip transmitter kits that came packaged with the RR501 precursor from
Egghead in 1985.

> >When testing the XTB I plugged in various transmitters to a power strip
in
> >my PC room.  Then, for each one in turn, I read the output at the far end
of
> >the house.  To my surprise, while the TM751 was outputting from .42 to 48
> >millivolts the CM11A clocked in at .58 to .62 millivolts.  Now I realize
> >that there could be a number of factors that attenuate each transceiver's
> >output differently but it really surprised me to see since I recall
having
> >measured it before and seeing an output that was half that of the RR501's
> >that I been using.  I am certain I've seen lots of tables that indicate
the
> >CM11A's relatively anemic output yet that's not what I am seeing in the
real
> >world.
>
> Since you really can't measure the maximum output, you can't draw
> conclusions. Different transmitters may also react differently to loading.

I'm beginning to think that might be part of what I am seeing - different
performance based on the power line characteristics.

>I  have measured several CM11As (or HD11As) as well as several other
> transmitters using both a scope and one of the pre-ELK ESM1 meters which
was
> calibrated for 10Vpp fullscale. The CM11A, CM15A, 30001 (Stanley Homelink
> tramsceiver), and HCPRF (Leviton All Housecode Transceiver) output 5-6Vpp
> while every other transmitter I've tested is in the 10Vpp neighborhood.

The good news is that apparently the XTB is a "great equalizer" when it
comes to variable input voltages.  When I plugged each unit (the CM11A, the
HCPRF and the TM751), in turn, to the power strip plugged into the XTB the
output at the other end was the same for each transmitter, which IIRC, was
.25 volts.

> It's easy to recalibrate the ESM1. Open it up and you'll see a
> potentiometer. Using an RR501 or TM751 in the same powerstrip, adjust it
for
> fullscale. You should then see about halfscale with a CM11A.

I may try that but the reality is that I'm more interested in real world
performance in my house.  To that end I was surprised that the CM11A signal
would end up being stronger at the end of a long run.  I would have expected
attentuation to occur uniformly over the same circuit pathway.

> >I also realize it could be just a fluke of the Monterey's measuring
> >circuitry as well.  The numbers are too small to make sense of with the
> >ESM1.  When the new XTB's arrive, I'm going to try to do as formal a
> >comparison as I can without an o'scope and may finally come 'round to
buying
> >the USB o'scope you had suggested a while back.  I've regained interest
in a
> >lot of X-10 gear that I had to abandon because the signals just wouldn't
> >reach everywhere no matter how much filtering I did.
>
> I haven't tried to keep up with this but I think this was the best
> reasonably priced USB scope a year or so back.
>
>      http://www.usb-instruments.com/oscillo_stingray.html

Yeah - that's the one.  Whether I'll be able to learn to use it to analyze
X-10 signals is another matter entirely.  Right now, though, I've got an
overly full plate.

> >Do you think the CE limits are safety based or are they just in place to
> >limit interference to nearby buildings?  I'm assuming interference is
more
> >important in Europe than the US because European population density is so
> >much higher.
>
> I spent nearly 20 years in the machine tool industry, importing capital
> equipment from Europe (and elsewhere). In those pre-CEdays many of the
> "safety" regulations in various European countries were intended to
protect
> local manufacturers from foreign competitors. I suspect there's still an
> element of that in most CE rules with frequencies and limits set to
maximize
> inconvenience for US and Asian companies.
>
> European power limits for wireless transmitters (e.g. Palmpad) are many,
> many times greater than FCC limits so I doubt population density is a
> controlling factor.
>
>      http://www.radiometrix.co.uk/apps/apnt102.htm
>
> Remember, also, that Europe uses 230V instead of 120V.
>

Good point about the RF range.  Peculiar they'd limit the output but it's
probably at the point where there's little chance of the signal propagating
to another house.

--
Bobby G.