Question is can I install a RR501/TM751 in addition to CM15A to improve the range of remote?
I did see the mods but could not figure out which one is good or bad. Can you please tell which one you did? I also want the CM15A to look nice with the modification in place as it is installed in a prominent place in the house. Is there any kind of frequency matching requirements for the antenna?
I'm going to try it anyway
...Isn't the F connector a double female? rofl
...Brian - it was dark-thirty, but when the threads are on the outside - it's MALE - when the threads are on the inside, it's FEMALE :'Actually I've always heard what you used called a two ended female also.
...What is the purpose of the 4 antennas on the corners?...My antenna theory is weak but I've seen similar constructed antennas for ham radio. I'll try to remember to look it up in the ARRL handbook.
axgupta1 - And to the other gurus here:PJ
http://www.cocoontech.com/index.php?showtopic=126
For the antenna pictured there. What is the purpose of the 4 antennas on the corners? If the bulkhead connector is properly seperating the center conductor from the grounding frame, how can the 4-downrods help reception - passive inductance?
Brian & Steven - You guys are absolutely correct, anf I am wrong. A search for "male f-connector" shows that the "union" that I thought was male, is actually a double femalw (as you said). What's being connected is the center-wire; the 'male' end. I learned something! Thanks!
So, how was everyone's Turkey?
And Dave W, thanks for the Ground plane explaination. So, in my attic where I'm not using a bracket, should I use an 18" piece? (or 36")
Then I stripped it up to 18" of exposed coax cable and with or without a grounding plane=Range of remotes and sensors shot up to to 40'+ in most directions.
That report is enough to get me to try the extra length.
Has anyone found differences in coax? RG-6/UQ?, RG-59? - etc?
Has anyone found differences in coax? RG-6/UQ?, RG-59? - etc?
You may want to do some searching on that. My memory says the 75-Ohm cables are better because the RG-59 can cause some sort of reflective interference. However... a quick search didn't confirm my gray-matter reference.
The frontend receiver of the CM15A is 50 Ohms. 1/4 wavelength antennas (single vertical element referenced to a ground plane) are generally ~50 Ohms as well. For optimal signal transfer between the 2, the cable impedance should be the same. Most people have 75 Ohm cable handy (or easier to get) because it is what most all cable companies use. It is not the best for optimal efficiency, but it will work better than no mod to the CM15A. If you have a very long cable run, I'd recommend keeping the impedance matched.
so will there be any issues using the RG58-50 Ohm with the F-connector?
I know it's weird, but if I hook a 20' cable to my modded CM15a and leave the antenna mounted on the wall, if I then move the CM15a around the room, in certain areas it will NOT receive RF.