[no subject]

>| It might be that it
>| would register on the latter but not the former. It's hard to say because he
>| really didn't provide much detail about the actual frequency and amplitude.
>
>The actual frequency was just over 200kHz, perhaps 205kHz.  That's as close
>as I can estimate looking at a scope.  The amplitude was quite low (maybe
>50mV--I don't remember), affecting only two-wire wall switches in their
>off state.
>
>To confirm the frequency response of the Elk meter at more reasonable amplitude
>I used an old remote control box which conveniently generates a steady 197kHz
>carrier at several volts.  Again the Elk read nothing but all X10 operation
>on the line was inhibited.  (I.e., this is an even better jammer than the
>200khz signal generator I had used before. :)
>
>Finally, I reprogrammed an RR501 (using my own firmware) to use 192kHz
>carrier for normal X10 transmission.  Its transmissions were accepted
>by every normal X10 receiver I tried (including a CM11a).
>
>As I've said, the cycle-counting technique used in many X10 receivers helps
>only with noise of lower frequencies and the analog filters don't have that
>sharp a cutoff.  Test tools are doing you no favor by implementing a band
>filter narrower than that of the actual receivers.

Anything greater than ~74kHz should meet the 48 cycles within the 650µS
window.

Obviously, the designers of the various test gear didn't look into this. I
cannot find any bandwidth specs for the Monterey but the manual says noise
greater than 110kHz might register as a false "1".

>Last time I posted about this you said you had ordered a signal generator so
>you could test the frequency responses for yourself.  What did you find?

I haven't done anything with it yet. It's still on my list but I can't
predict when or if I'll get to it. I have new health issues that are taking
priority.