- First Name
- Kendall
- Joined
- Feb 5, 2018
- Threads
- 8
- Messages
- 337
- Reaction score
- 526
- Location
- Santa Clarita, CA
- Vehicle(s)
- 2018 Rubicon
We think that GMRS will *eventually* start to win out over the stranglehold that CB has had as the long-standing standard for off-road communication. CB entered the scene in the late 50's and grew in popularity in the 70's and 80's. As others have noted it is in the 27MHz frequency and amplitude modulated (AM) which was a less costly method of transmitting. The low frequency, long wavelength, AM signal is very susceptible to interference - perhaps especially solar flare activity (seriously). For us, CB has exactly one (non-trivial) advantage over GMRS and that is its historic popularity... and that's it.
In contrast to CB, GMRS is in the UHF band at 462MHz and is FM. The signal is going to be much clearer in GMRS. GMRS also has much higher (legal) transmit power capabilities - it's common to see 15- 20 watt moblie receivers and up to 40-watts on the higher-cost mobile units. 50-watts is the limit - compared to a scant 4-watts for CB.
But in the Jeep world, there's yet another significant advantage that GMRS has over CB. Jeep's don't have a large metal roof as many other vehicles have. These large metal roofs provide an excellent ground-plane for an antenna - and it's just missing on a Jeep. This inherent disadvantage is much more of a deficit for the low frequency (long wavelength) CB radios. Ground planes are important for the best GMRS signal as well - but UHF-band radios are a little more tolerant of this.
All of this means that GMRS can significantly out-perform a CB radio - in both distance and clarity of signal. In some conditions, CB will give you a range of 2-3 miles whereas in those same conditions, GMRS may deliver 20+ mile capability. Suffice to say that although there may be a couple of very specific scenarios where CB might match or best a GMRS, in the VAST majority of scenarios, GMRS will be significantly better.
There IS a licensing requirement for GMRS, but it is almost trivial. No test and a $70 fee gets you a GMRS license good for 10-years and covers your immediate family.
In contrast to CB, GMRS is in the UHF band at 462MHz and is FM. The signal is going to be much clearer in GMRS. GMRS also has much higher (legal) transmit power capabilities - it's common to see 15- 20 watt moblie receivers and up to 40-watts on the higher-cost mobile units. 50-watts is the limit - compared to a scant 4-watts for CB.
But in the Jeep world, there's yet another significant advantage that GMRS has over CB. Jeep's don't have a large metal roof as many other vehicles have. These large metal roofs provide an excellent ground-plane for an antenna - and it's just missing on a Jeep. This inherent disadvantage is much more of a deficit for the low frequency (long wavelength) CB radios. Ground planes are important for the best GMRS signal as well - but UHF-band radios are a little more tolerant of this.
All of this means that GMRS can significantly out-perform a CB radio - in both distance and clarity of signal. In some conditions, CB will give you a range of 2-3 miles whereas in those same conditions, GMRS may deliver 20+ mile capability. Suffice to say that although there may be a couple of very specific scenarios where CB might match or best a GMRS, in the VAST majority of scenarios, GMRS will be significantly better.
There IS a licensing requirement for GMRS, but it is almost trivial. No test and a $70 fee gets you a GMRS license good for 10-years and covers your immediate family.
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