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🛡Home Security => Home Security General => Topic started by: Jeff M on March 06, 2011, 08:20:49 PM

Title: SC1200 RF Antenna
Post by: Jeff M on March 06, 2011, 08:20:49 PM
I recently relocated my SC1200 console and one of my door sensors stopped working.  Since there were two outside walls between the sensor and console, I figured the signal strength of the sensor was not strong enough to penetrate the walls.  I verified this by moving the console closer and the sensor started working again.  As an experiment, I stretched out the AC power cord of the console instead of having it bunched up.  The door sensor that was having problems started working reliably again.  Perhaps I discovered the obvious, but the SC1200 seems to use the power cord as an antenna, and extending it instead of having it bunched up greatly extends the reception range.  Probably not an earthshaking discovery, but I'm an X10 newbe and this is exciting for me!
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 07, 2011, 06:11:03 AM
Sounds like a good find to me.  >!
Helpful from me.

One of these days. I may open mine up and take a look inside.
That is after I commit to keeping it. After I open anything. It gets a sticker saying opened and I would never return it as it was opened.

I did open my Radio Shack 49-1000MC console.
The antenna wire is wrapped around inside the case and the receiver board is the same as the one in the updated TM751's.

Maybe when you stretched out the power cable. It coupled the RF signals into the case mounted receiver antenna.
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 08, 2011, 07:36:41 AM
The SC1200A has the same receiver board in it as the 49-1000MC.
The antenna wire. Like the 49-1000MC. Is in a channel in the case around the edge.

I dinged the SC1200As case so it is all mine now.  ::)
Title: Re: SC1200 RF Antenna
Post by: lviper on March 08, 2011, 09:33:02 AM
I dinged the SC1200As case so it is all mine now.  ::)

Scratch and Dent Sale???
Title: Re: SC1200 RF Antenna
Post by: Jeff M on March 08, 2011, 11:05:21 AM
So in theory, the antenna wire can be routed outside of the case, and extended.  Your thoughts?
Title: Re: SC1200 RF Antenna
Post by: tom j on March 08, 2011, 06:14:24 PM
I recently relocated my SC1200 console and one of my door sensors stopped working.  Since there were two outside walls between the sensor and console, I figured the signal strength of the sensor was not strong enough to penetrate the walls.  I verified this by moving the console closer and the sensor started working again.  As an experiment, I stretched out the AC power cord of the console instead of having it bunched up.  The door sensor that was having problems started working reliably again.  Perhaps I discovered the obvious, but the SC1200 seems to use the power cord as an antenna, and extending it instead of having it bunched up greatly extends the reception range.  Probably not an earthshaking discovery, but I'm an X10 newbe and this is exciting for me!


Definitely worth a helpful to me. Yep here's to ya!   >!    #:)

Tom j.
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 09, 2011, 06:19:32 AM
I have been thinking about the antenna.

It runs around the edge of the top case. Across the front, around the side and back around the back edge of the top case.

I believe the top and bottom case parts. When assembled hold the wire in the channel between them. So the wire is running where the case half seams are.

When it is sitting on a shelf or table. It is on the horizontal plane.
When mounted on a wall. It is on the vertical plane.

Rusty RF theory here.
When on the table in the horizontal plane. It would be more sensitive to signals in the vertical plane.
When on the wall in the vertical plane. It would be more sensitive to signals in the horizontal plane.

So wall or table mounting could make a difference in reception of sensors and remotes.

Jeff M; I had not given much thought to extending the antenna externally.
It uses a low voltage power supply. So I don't think there would be any shock hazards.
Physically not sure how it could be done.

Attached file is the RS 49-1000 but close to the SC1200A.
Title: Re: SC1200 RF Antenna
Post by: Jeff M on March 09, 2011, 11:57:28 AM
Thanks for the input.  If I did move the antenna outside of the console, I would probably just remove the wire from the channel in the case, then let it fall away from the case.  Possible tape it vertically to the wall.  Since extending the power cord away from the console seems to help reception, doing the same with the internal antenna might help also.  Just guessing that the internal antenna is 1/4 wave since there isn't room for much length.  Wondering if extending it outside the case, and lengthening it to 1/2 wave might help.  Currently all sensors are being seen by the console, but curious to experiment. 
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 09, 2011, 12:54:04 PM
I just had another thought on the extending the power supply cable.
One of the four wires in it is the common. Maybe you are extending the boards ground plane.

If you decide to move the antenna wire external.
The bottom cover does not come off when the five screws are removed.
There are a few catches holding it on. That is how I damaged my case. Popping the catches.  :'

All the electronics are mounted on the top cabinet piece except the siren sounder. Its assembly is clipped to the bottom cabinet piece with a pair of wires to the main board.

When you put it back together. Make sure the positive battery terminal soldered to the board. Goes back into the slot in the battery holder on the bottom. Guess you know how I found that one.  ;D
Title: Re: SC1200 RF Antenna
Post by: Jeff M on March 09, 2011, 02:17:33 PM
Thanks for encouraging me to leave the case intact, at least until the warranty period is up.  Any idea why a rf repeater is no longer available?
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 09, 2011, 06:27:06 PM
No idea why the RF Repeater is gone, but it has been for a fairly long time.

Good decision on not opening the SC1200A. If it works don't mess with it.
Title: Re: SC1200 RF Antenna
Post by: tom j on March 09, 2011, 09:23:06 PM
No idea why the RF Repeater is gone, but it has been for a fairly long time.

Good decision on not opening the SC1200A. If it works don't mess with it.

They didn't work. Completely screwed up my macro's by repeating them and took me weeks to trace it to the repeater, that's just one  I couldn't begin to name the other problems I had with mine Good Riddance! Just my opinion.


Tom j
Title: Re: SC1200 RF Antenna
Post by: Brian H on March 10, 2011, 06:10:18 AM
Thank you for the repeater problems information.
Now we know why it was discontinued.