Elk ESM1...sensitivity?

Guy Lavoie

Active Member
I had one of those "hmmm" moments the other day: I was troubleshooting a weak X10 signal problem around my PC/lab area and at one point I had my ESM1 signal meter plugged in alongside a PSC-05 that wasn't connected to anything. I was sending X10 from another part of the house and couldn't see any indication of a signal on the ESM1...yet the LED on the PSC-05 was blinking twice, indicating that it was receiving a valid X10 signal pair.

I thought that the ESM1's lowest LED bar would indicate a very weak signal that some X10 receivers might miss, but instead it appears that the PSC-05 can reliably receive a signal that is too weak for any indication on the ESM1. Has anyone else ever noticed this? The ESM1 has been very useful and I don't think that its defective or anything, but I am a bit surprised. Or have I discovered a magic PSC-05? :D
Well, the only "mod" I did is the capacitor mod, which concerns signal transmission for the most part. Other then that', its stock. I have several of these, so I should try out a few more...
Guy Lavoie said:
Well, the only "mod" I did is the capacitor mod, which concerns signal transmission for the most part.
Is this mod really worth the effort Guy? Have you noticed an increase in signal strength?
Yes, definately. This mod came about as a result of not being able to send X10 reliably when I first got my Ocelot. I could see that the Ocelot was retrying the transmission a total of 5 times before giving up. I could also see that the PSC-05's LED would dim slightly when it was transmitting (or trying to). Its after examining the TW-523's schematic and hearing about the previous "solution" of cutting out the LED to save power that I came up with the idea of trying a larger capacitor to replace C12. I found that I could physically fit a 470uF cap in the place of the 100uF that was there. It worked really well after that so I mentioned it on the Futurestandard ADI mailing list and CHA newsgroup, and many other people have since used this mod with good results themselves.
Hey, I might try it. I believe I did this on a TW523 and didn't notice much change, but can't really remember the details (man, I'm getting old!).

Thanks again. :D