Re: CM11A hangup: Any better products?

[Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx>]

Hello Dave,

>      http://www.edcheung.com/automa/lm465.gif
>
> Could you use it to explain your procedure?

Ok, it's been a long time but I'll try.

I took a toroid of about 1" OD, 43 material. 77 material is probably
better but I just had that on the desk. I wound about 20 turns bifilar
onto it, insulated wires, about one twist every half inch. The secondary
to a short coax which went into the scope's input, with 499 Ohms in
series with the winding. Primary one side to module ground, the other
side via a 5K resistor in series with a 100pF cap to pin 1 of the 78561.
Could have been the other side of the 33pF cap, I don't remember
exactly. Then I peaked the inductor while sending lots of commands on an
unused code, to avoid clacking the relays too much.

 From an RF engineer's point of view this was horrible. Mismatch galore
but it worked. I just needed a quick and dirty fix because the missus
ain't happy when the X-10 lights are on the fritz.

Don't use a screwdriver for this. Safety is one reason but the core is
also ferrite which is brittle. A metal blade might break a chunk out of
it or crack the whole core. If you don't have a Bernstein screwdriver
this would be the perfect excuse to eat a Haagen-Dasz bar to get the
wooden stick. Almond crunch are the best ;-)

You can't use a scope probe directly. Not just for safety (module GND
could be hot) but its input capacitance can cause de-tuning and you
might end up on the wrong frequency once you disconnect it.

> BTW, there is a schematic of the first version of the SmartHome 1132
> (mentioned earlier in this thread) available at...
>
>      http://home.pacbell.net/lgalvin/pwrlinc.gif
>
> I suspect the X-10 circuitry is still the same on the latest versions.

Thanks. It seems to be an older version since it doesn't have a backup
battery. Also, I read somewhere that they might have a Dallas realtime
chip. I think the new version is called 1132CU.

Regards, Joerg

http://www.analogconsultants.com