mmckenna
I ♥ Ø
We hear a lot of people talk about the consumer grade CB antennas. We see a lot of people (me included) strongly recommend the Larsen NMO-27 antenna.
There are good reasons for both types, but here's some actual proof of what you get.
This is a 20 year old (at least) Larsen NMO-27 on a permanent mount NMO on the roof of a 2011 Ford F-150 crew cab. The NMO mount is near the back of the cab roof. Not the ideal position, but the center of the cab is reserved for my work radio antennas.
Plots were generated by an Agilent N9342C spectrum analyzer with a built in tracking generator.
First plot shows the 26.000MHz to 28.000MHz range.
Marker 1 is set to CB channel 1 26.965MHz
Marker 2 is set to CB channel 19 27.185MHz - center of the CB band.
Marker 3 is set to CB channel 40 27.405MHz
SWR readings are:
Channel 1 = 1.33:1
Channel 19 = 1.05:1
Channel 40 = 1.33:1
Second plot show just the CB band. 26.965MHz to 27.405MHz range.
Markers are set as above. 1 on Channel 1. 2 on Channel 19. 3 on channel 40.
SWR numbers are a bit different due to narrowing the sweep gives me better control of their placement.
I don't have any 3/8x24 mounts or any of the consumer grade antennas to compare. But at least here's proof that these are excellent antennas when set up correctly.
There are good reasons for both types, but here's some actual proof of what you get.
This is a 20 year old (at least) Larsen NMO-27 on a permanent mount NMO on the roof of a 2011 Ford F-150 crew cab. The NMO mount is near the back of the cab roof. Not the ideal position, but the center of the cab is reserved for my work radio antennas.
Plots were generated by an Agilent N9342C spectrum analyzer with a built in tracking generator.
First plot shows the 26.000MHz to 28.000MHz range.
Marker 1 is set to CB channel 1 26.965MHz
Marker 2 is set to CB channel 19 27.185MHz - center of the CB band.
Marker 3 is set to CB channel 40 27.405MHz
SWR readings are:
Channel 1 = 1.33:1
Channel 19 = 1.05:1
Channel 40 = 1.33:1
Second plot show just the CB band. 26.965MHz to 27.405MHz range.
Markers are set as above. 1 on Channel 1. 2 on Channel 19. 3 on channel 40.
SWR numbers are a bit different due to narrowing the sweep gives me better control of their placement.
I don't have any 3/8x24 mounts or any of the consumer grade antennas to compare. But at least here's proof that these are excellent antennas when set up correctly.