X10 Community Forum
🔌General Home Automation => Automating Your House => Topic started by: ronsonol on May 19, 2021, 10:12:39 PM
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I hope someone has ideas for me as I am at a loss for direction.
I have a cm15A that for many years had not great range. Trying to add some additional coverage I attempted the f connector mod.
1. I snipped the existing wire leaving a length that I soldered to the center of the f connector and attached a small telescoping antenna.
I grounded the f connector to the vss point. Did not work, so then I grounded it to the ground point on the receiver. Also didn't work.
2. I removed the f connector and soldered a length of wire to existing length left from original antenna to make it 9 1/4", and it still didn't work.
3. Last thing I did was solder a new 9 1/4" wire directly to the board at the antenna point. Didn't work.
Now to say it doesn't work isn't quite accurate, the cm15a occasionally picked up the signal but only if the palm remote is is basically right on top of the wire. I went from around 10-15 feet range down to 1".
I've checked the rf board, no bridging of points at ground and antenna. It gets 5v to the first pin. The RF pin is showing around 2v, and will occasionally jump up to 3.4v or down to 1.4v when I press keys on the remote, but rarely does it work even with the remote nearly right on top of the unit.
I appreciate any guidance you have.
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Is your CM15A the older designed model with a RF receiver and transmitter set of daughter boards soldered to it. Or one of the later models with the RF section all on the main board and has a surface mounted controller chip?
The older one is in the FCC Database and one of the files is the schematic of the original version and internal photos. That may give you some help.
https://apps.fcc.gov/oetcf/eas/reports/GenericSearch.cfm
Grantee B4S
Product Code CM15
In the details choice
Any possibility you have some sort of RF interference killing the reception?
There is also a good set of information here. https://www.laser.com/dhouston/ImproveCM15A.html
On the RF mod and ho we added 4 small capacitors to the main board for better operation. It is also the older designed model.
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Hello, thanks for the reply. I have the older model with independent RF boards. I don't think it would be interference as it was working before I got my hands on it.
Thanks for the information I will check it out.
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I looked at the picture of the RF board and a couple things stand out to me.
In the picture by antenna is soldered to the point at the left red arrow. And there does not seem to be the continuity to the components below as this picture would indicate being soldered directly to those components. Also, the round solder point at the bottom with red arrow on right. I don't have a solder blob there, but I did find a small piece that may have been knocked off. Any idea is this is necessary, is it meant to bridge the round point just beside it?
RF board from database site mentioned above
(https://i.imgur.com/hY7ZFcW.jpg)
Below is my RF Board.
(https://i.imgur.com/06A4Md2.jpg)
The Blue marking indicates where I have continuity on the multi meter from the antenna wire.
It stops going any further beyond the blue marking. The red lines indicated continuity between all those points.
(https://i.imgur.com/UjAGqMP.jpg)
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I can't help with this, but I would like to point out that comparing the picture to your component won't help a whole lot. It's pretty clear to me that your daughter board is different than the one from the FCC. I would NOT attempt to make changes to the components to match the FCC picture when you don't have the same version.
FWIW, I always try to take pictures of things before I modify/fix them in case things don't work. I then have a reference to what used to work or at least what it looked like before I touched it. There are a lot of SMD resistors etc on that daughterboard and it would be fairly easy to melt solder on one which could allow it to slide to contact another solder blob. Depending on what it's job was supposed to be, that could render things non-functional and/or permanently break things.
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Thanks for the reply and yes I understand.
Thing is though, my first 3 attempts to add a new antenna didn't even involve touching the RF board. Only as a last resort did I solder a new wire to it, and I don't think there is any damage. Just don't understand how the signal travels into the chip, if the continuity stops at the top cap.
Thanks again,
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RF is magic. I'm an ME so the only thing I know for sure is when you let the magic smoke out, electronics dont work anymore.
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bkenobi Has found a difference in hardware versions.
The FCC database is the original version.
The one you have is a set of revised daughter boards with what looks like surface mounted parts. So do not use the database photos as a guide as it does not match your receiver board.
The solder blob was probably stuck on the board and not connecting things together. I would discard it and not try and find anything not properly connected.
The latest photos of the present version. Has the RF receiver and transmitter on the main board [screened PCB0051A in my photos] with surface mounted chips.
Is the receiver antenna wire the grey one in your versions receiver photo?
Was the receiving antenna wire inside the antenna tube or is it connected to a metal plate and the antenna is a separate assembly.
It is coupled with chip capacitors and maybe terminated by a resistor. With surface mounted parts. I would not suspect there would be continuity from the antenna to the receiver chip itself. As a functioning capacitor will read open with a meter and passes RF signals to the receiver chips antenna input and blocking DC voltages from the receivers input.
I will look at your photos and see if anything pops out.
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It is coupled with chip capacitors and maybe terminated by a resistor. With surface mounted parts. I would not suspect there would be continuity from the antenna to the receiver chip itself.
All the RF receivers I've seen couple the antenna through a capacitor.
The RX3310A datasheet shows schematics for typical applications.https://pdf1.alldatasheet.com/datasheet-pdf/view/1246343/PTC/RX3310A.html (https://pdf1.alldatasheet.com/datasheet-pdf/view/1246343/PTC/RX3310A.html)
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Yes, the second/third picture is my rf board.
The grey wire in the picture is the current wire attached as the antenna. I've tried a couple types of wire, and this grey wire I stole from the rf transmitter.
The Original wire was inside the antenna tube, but after the failed f connector mod attempt, it no longer is.
Thanks,
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Look at the photos Blue Lines you used to indicate continuity. Make sure their isn't a solder blob or thin splash to the run around the top edge of the board.
Since you had the issue as soon as you moved the original antenna wire. I had wondered if moving it caused the antenna input on the receiver board and it touched something it was not meant to be connected.
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I checked where the blue lines are, and there is no bridging of any sort to order areas. The only connections are made with those points that are all linked to the same trace.
Thanks.
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Just don't understand how the signal travels into the chip, if the continuity stops at the top cap.
Your meter will not show continuity through a capacitor as a capacitor does not pass DC but only AC.
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I am not too sure if the receiver board with the 20 pin RX3310A chip shown in the FCC Database ever made it to production.
I have an early CM15A Date Code 04J41. It has a 18 pin RX3310A chip on it and looks very much like the photos you posted.
Mine has a silk screened H11245A 18 on the back side with a coil.
I just checked my latest CM15A Date Code 08B09. It also has a H11245A receiver board.
I will look at mine and see if anything pops out.
Since your first change was only connect the original antenna wire to the F connector. Maybe moving the wire caused the connection on the receiver to move and touch something or you somehow zapped the RX3310A chip and it is no longer functioning correctly.
If you are also doing things like timers and macros. On the power line. Are they still working and it is only the RF having a problem?
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Hi, thanks again for the reply I really appreciate the help. Everything else functions normally. It is only RF reception that has issues.
I connected to Active Home, cleared memory and uploaded again with no improvements. If I get the remote right up close to the antenna, almost touching, the RF reception does often work. I can see that activity in the activity monitor and the corresponding device receive the signal over power line.
On the back of my board is =11245A 32, with the coil you mentioned.
I've done all the testing I can, resistors have the value in ohms they should. Incoming 5.5v gets stepped down through two resistors. First to about 5.1v through 100ohm, and then to about 2 to 2.2v through 100k ohms before going to the chip. That cap the antenna travels through tests fine as far as I can tell, one leg to ground and the other not. Further down the path the other caps and inductor test fine before heading into pin 14. The data output pin does make it to the chip P10792M on the mainboard at 2.2v.
Since I was careful with what I was doing before touching the board (remove from hot glue the length wound up inside and clipping old wire only) I can't help but think something was special about the original wire or the fact it was in the plastic tube, but to me it just looked like simple aluminum stranded wire.
Also, on one of the data sheets I pulled up it says min input voltage is 2.4 volts, and max of 6v. This might be the issue as I am only seeing between 2 to 2.2v. The 5v pin measure 5.5v, but after it travels through the resistors in series it drops to about 2.2.
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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.
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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.
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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?
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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.
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The transceiver House Codes in AHP didn't get disabled some how?
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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.
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Thanks for the information.
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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.
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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.
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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.
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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.
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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
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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.
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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
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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.