Rich wrote:
Interesting combination, maybe I will give that a try on the truck. I thought FME's were similar to PL259's when it comes to performance shortcomings on UHF and above. Either way (at 800mhz) you are probably picking up 1-1.5db with the better cable and another 1-1.5db with the correct connection/shielding at the mount base.
Good point- Im not sure myself about FME loss but know the antenna companies tend to use the connector on their cellular offerings so I kinda went by their lead there.. I did one of the installs with an SMA NMO mount so have the ability to test that if I needed to. And now I'm intrigued!
From the Times Microwave Cable Calculator.. 17feet at 810mc
Cable Assembly Performance LMR240
Cable Run Attenuation: 1.2 dB
Total Cable Assembly Loss: 1.4 dB
Cable Run Efficiency: 75.6 %
Cable Run Time Delay: 20.56 nSec
Cable Assembly Performance RG-58
Cable Run Attenuation: 2.3 dB
Total Cable Assembly Loss: 2.4 dB
Cable Run Efficiency: 58.6 %
Cable Run Time Delay: 26.17 nSec
So according to their calculator only 1db.. But almost 20% more efficient.. And with other factors such as going from big button to small button.. 100% shielding like you mention, and I used a Laird B7603 5/8~ antenna to replace the center "curly" coil wire antennas. Just trying to take out the weak links out of the antenna system.
I think if nothing else this is a good post to point all the guys that complain that they can't hear the next counties 800 system with their 100 feet of rg-58 that they ran up a tree to their antenna of choice. :)