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[Brian H]

Nothing special about the wire in the antenna tube. Looks like maybe #26 or thinner stranded.
To get the proper length for 310MHz signal. Part of the wire not in the 4.5" plastic tube was jumbled up in a random ball in some and later the extra was wrapped around  the case in a more orderly fashion.

[ronsonol]

I checked and the chip is getting 5v at both vcc pins.  The data out is sitting around 2 to 2.2.  I took a 10k smd resistor and swapped out the 100k and no change on RF, except the voltage was sitting around 2.7v on the data pin.  So I put the original 100k back.
Everything else about the unit is working fine.  The RF only picks up if the palm remote is right on top of the wire.
I'm no EE but I've checked the components I could on the board, given it works with the remote right on top it must be a antenna in or gain issue?

I thank everyone of the assistance.

[Noam]

This may be an obvious question, but I didn't see it mentioned in the troubleshooting anywhere:
Have you checked the batteries in the remote?
Have you tried with the different remote?

Is it possible that the problem with your signal strength is with the one being *transmitted* to the CM15A, and not with the *receiving* of that signal?

[ronsonol]

That's a very good point and you are right I did not test that as part of my troubleshooting.  But I was trying multiple remotes.
Just checked battery voltages to be sure and they at 1.5v.

I have a frequency meter and the remotes are solid at 310.00. 

I also have a secondary receiver I put together months ago using a RTL-SDR dongle tuned to 310.00 and rtl-443 program with X10 support running on Linux and homeassistant.  I have this picking up the remote signals as well, passing that to mqqt and then on to home assistant to broadcast that over the powerlines.  It's working well.  Signal pick up is not reaching the entire house, which is where modifying the CM15a came in.

Thanks.

[Brian H]

The transceiver House Codes in AHP didn't get disabled some how?

[ronsonol]

I did look there, and to be safe I cleared everything and uploaded/updated again.  Transceived house codes set to auto, and monitor is set to the one I have the most devices on.   It still sees the RF from remotes, but again only if the remote is right on top of the wire.  Thanks.

[Brian H]

Thanks for the information.

[Tuicemen]

I did look there, and to be safe I cleared everything and uploaded/updated again.  Transceived house codes set to auto, and monitor is set to the one I have the most devices on.   It still sees the RF from remotes, but again only if the remote is right on top of the wire.  Thanks.

You realy shouldn't  set Trancieved house codes to Auto. It should be set to specific and select all house codes. Even if using the AHP software as your main automation control the auto function never worked reliable.

[Brian H]

I would suspect an antenna input issue myself. Bad cap, solder blob short on the RF input terminal or components. Internal RF amp is failed in the chip. I guess the chips RF output to the chips internal mixer or other functions could have an issue. With the components being used.

I have a CM15A with an F Connector. With just the F Jack and internal short wire from the receiver board to the center pin socket. It was about 10 feet and spotty depending on how the remote was pointed farther out. With a HR12A Palm Pad.

My trying shorting the F Jack input was not a successful test.

The RX3310A data sheet Dave pointed out. Is not too detailed on its operation. The older HiMark version of the chip data sheets is not much better. Though I attached it as it has a few extra pages on how it operates.

I have not seen any schematics with voltage readings.
The 2.0 to 2.2 volts on the data pin is what mine is sitting at the processors input. The receiver does not have any squelch functions and the output is a steady stream of static until an RF command is received. Then their is a set of short burst of information and back to static again.

[ronsonol]

Thanks, and yes I suspect a antenna input issue, I cannot find any shorts.  That or something that is failing in the chip. 
Reception has decreased over time hence the desire to improve.

I thought the first cap might be bad, since the antenna signal travels first trough that.  I grabbed one, value unknown, that had the same footprint, and swap it in. The RF didn't work at all, so I put the original back and it was at least back to working close up. 
Another thing I tried was to put down some flux and reflow the solder around the chips 18 pins.  Last night that didn't seem to help, but at least like the cap and resistor swaps for testing didn't make things any worse.

I was testing today and the range has improved actually, from inches away to a up to 4 feet using the palm pad remote.  It is very directional however, only working at that distance from head on and a 1-2 feet below the location of the cm15a.

[dhouston]

Given that you went from around 10-15 feet range down to 1" after your attempted mods it would seem you have damaged the circuitry or the RX3310A chip.

[JeffVolp]

Here in the southwest we have a problem with static electricity.  Years ago I brushed up against the antenna of a RR501 and heard a snap.  After that the RR501 was toast.

Jeff

[dhouston]

Here in the southwest we have a problem with static electricity.  Years ago I brushed up against the antenna of a RR501 and heard a snap.  After that the RR501 was toast.

Wow! The RR501 antenna is capacitively coupled through about 1/8" of plastic.

[JeffVolp]

Here in the southwest we have a problem with static electricity.  Years ago I brushed up against the antenna of a RR501 and heard a snap.  After that the RR501 was toast.

Wow! The RR501 antenna is capacitively coupled through about 1/8" of plastic.

Yeah, I took it apart and saw that.  My guess was just the capacitance coupling of that many KV spike was enough to damage the chip.  Since then I've been careful not to get close to the antennas.

Jeff

[Brian H]

I saw an X10 modification on an RR501 antenna.
They bridged the coupling through the plastic with a small value capacitor.

The TM751 has a similar type coupling.
My last ones. Are not that recent any more. They have a RF daughter board with the RX3310A receiver chip being used.