A typical X-10 310 Megahertz receiver such as the MR26a's reception can greatly be improved with a custom antenna rather than the stock pig-tail wire. This how-to will show you how to make a one-quarter wave ground plane antenna tailored for the MR26a's frequency of 310 Megahertz.
First step is to modify your MR26a or other receiver so it can accept an external coax connection. This is performed by installing a bulkhead "F" or other connector (such as "BNC") on the end of the pigtail connection. An elaborate tutorial is already in place for this task at this location (scroll down to the "Modify the MR26" line).
If you have another type of receiver you will need to modify it so it can accept an F or other means for connecting a coax cable to it.
To make this antenna you will need the following items (some are shown below):
Chassis Mount UHF SO-239 Coax Connector (Radio Shack item # 278-201)
F to SO-239 Adapter (Radio Shack item #278-258C)
1/16" thick Brass Rod (approximately five feet length)
#4 Ring Crimp Lugs
4-40 Screws, lock washer, and nuts (four sets)
Solder Iron and Solder
Hacksaw (What would be a HA project without one of these)
We will need to calculate the one-quarter wavelength for 310 megahertz. The formula WAVELENGTH EQUALLS THE SPEED OF LIGHT DIVIDED BY THE FREQUENCY is used to calculate the total Wavelength, this will then be divided by four to determine the "one-quarter' wavelength.
Speed of Light = 1.180 E10 inches/sec
Wavelength = 310 E6 hertz
So plugging these numbers into the above formula yields:
Wavelength = 1.180 E10 / 310 E6, which equals an overal wavelength of 38.07 inches. We must then divide this number by four to obtain the one quarter wavelength distance (38.07 / 4) of 9.5 inches.
Assembling the Antenna:
First take the brass rods and cut to five each 9.5 inch lengths. Sand one end (this will be the solder end).
Solder one rod into the center of the chassis mount connector as shown.
Then insert one end of the brass rod into the #4 ring crimp lug and solder in place as shown:
Do this for FOUR of the rods (one end only).
Attach the assembled crimp lug/rods to the chassis connector's holes using the 4-40 hardware. Insure a secure/tight fit onto the connector. Bend the lug/rods to a 45 degree angle "away" from the center top rod as shown.
Repeat this assembly for the other three rods.
The antenna is now ready for mounting. Mount "upside down" in a location such as an attic and insure the coax cable does not go "thru" the antenna as shown.
Use a coax cable such as RG6/U and F connectors, connect to the MR26a. I'm running approximately 50 feet of coax between my MR26a and antenna with no problems (in my new home, picture above was in my old home. Also note I said NOT to run the coax through the antenna, i.e not the way the above photo shows).
Test out your new increase coverage.
Well, thats it. You just completed this project that increased your x-10 receiver coverage for less than ten bucks in parts.
Edited by BraveSirRobbin, 15 May 2005 - 08:26 PM.