Re: Can wireless reliability be enhanced?

[nobody@xxxxxxxxxxxx (Dave Houston)]

"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> wrote:

>"Dave Houston" <nobody@xxxxxxxxxxxx> wrote in message
>
>> Is there an FCC ID number on the device? Sometimes there are schematics in
>> the papers filed with the FCC.
>
>FWIW, my very similar looking unit from RatShack says: B4S61-2609R.

The "B4S" is X-10's ID. There are no attachments to the B4S61-2609R FCC
filing. (About 5 years ago, most of the attachments to X-10's FCC files were
removed. I was surprised to find the CM15A filing had a schematic attached.)

The problem with many of X-10's devices is that they use a transformerless
power supply and use the hot side of the mains as electronic ground. This is
the reason they isolate the antenna on the TM751 and RR501 by using the
plastic of the case as the dielectric in a "capacitor" that couples the
antenna to the RF input circuitry.

For battery powered devices, for those like the MR26 which is powered from
the PC serial port, and for those like the CM15A that have isolated power
supplies, it's generally safe to replace the antenna with a coax connector
and then connect an amplified antenna to the connector. For other devices
without isolation, this could put 120V on the coax shield creating a hazard.

It is possible to isolate the antenna connector by using a 1:1 isolation
transformer between the coax connector and the RF input circuit. The
transformer must be inside the case and the primary and secondary must be
isolated (many 75:300-ohm baluns are not isolated). I have used a small Toko
transformer (B7T-456DS-1012) available at Digikey. MiniCircuits also has
some SMD isolation transformers that will work. There will be an insertion
loss from the transformer but the amplifier more than makes up for it.
Without an amplifier the insertion loss may be enough to make adding a more
efficient antenna pointless.

     http://www.minicircuits.com/

At this point anyone who doesn't understand the information I've given
should forget about trying to change their antenna lest they end up floating
on a cloud playing a harp.