X10 Community Forum

🔌General Home Automation => Automating Your House => User Modified Devices => Topic started by: pseeker on August 17, 2012, 09:50:46 AM

Title: ds10a antenna mod?
Post by: pseeker on August 17, 2012, 09:50:46 AM
Wanted to get the community opinions on extending the range of the DS10A.... Background info, I have sc1200 security with four remaining pesky DS10A out of range even with this sc1200 antenna  mod: http://forums.x10.com/index.php?topic=26293.0 (http://forums.x10.com/index.php?topic=26293.0)

1. Use this mod (site has been translated using google).  http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.domotica.famschenk.eu%2FDS10A_op_433Mhz.html (http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.domotica.famschenk.eu%2FDS10A_op_433Mhz.html)   
2. Instead using a  433 Mhz SAW transmitter board in above link use a 310 Mhz transmitter made from
    a. 315Mhz rf Arduino transmitter from ebay http://www.ebay.com/sch/i.html?_nkw=315mhz+transmitter++rf+Arduino&_sacat=0&_odkw=315mhz+transmitter++rf&_sop=15&_osacat=0 (http://www.ebay.com/sch/i.html?_nkw=315mhz+transmitter++rf+Arduino&_sacat=0&_odkw=315mhz+transmitter++rf&_sop=15&_osacat=0)  or http://us.dinodirect.com/se-315mhz-transmitter-board-module/currency-USD.html (http://us.dinodirect.com/se-315mhz-transmitter-board-module/currency-USD.html)
    b. Solder in 310Mhz SAW from http://www.cdadapter.com/sr310.htm (http://www.cdadapter.com/sr310.htm)
Title: Re: ds10a antenna mod?
Post by: dhouston on August 17, 2012, 03:59:25 PM
It may not help.

That the antenna mod did not solve your problem is a strong indication that it is not fundamentally an issue of range.

The door/window switches, motion sensors, etc. are all LC tuned with very inefficient antennas. The SC1200 has a narrow-band super-heterodyne receiver and it also uses LC tuning. Odds are they are operating on slightly different frequencies.

Have you tried the passive radiators suggested here...
Even if it's only a temporary test, it should be the first step. If it does not help, it is most likely not a range issue since that can give a significant range increase.

As I noted in a similar thread yesterday, I am waiting for delivery of a key component that is a special order and has a 4-5 week lead time. Once I get those components I will build some wide-band super-het receivers that should address the tuning issue.

If you do not want to wait, try using an RM1SG super-regenerative receiver in the SC1200. It has a wider than usual bandwidth, even for super-regens. There's a thread on using it in a CM15A...

Also, it is not 100% clear that the SC1200 antenna is isolated from mains voltage. Lacking such proof (i.e an X10 schematic), I would make certain that any exposed metal from the antenna mod (e.g. wire ends) be insulated as a precaution. I've also designed a galvanically isolated antenna connector. As it uses a 1:1 50-ohm RF isolation transformer, it should work whether an antenna is isolated or not. However, I'm not at all sure it will fit within the SC1200 case. Since I've no need for a security system, I do not want to buy one just to see if the isolator can work with it.
Title: Re: ds10a antenna mod?
Post by: pseeker on August 17, 2012, 05:37:20 PM
The antenna mod SC1200 worked well... along with some passive antenna trick on the DS10A.  However my house has those metal 2x4 studs between walls. So there are few sensors still out of reach.  If figure the 310Mhz SAW mod 310MHZ will allow me to install a "real" antenna