TJ2
TJ Expert
I also still have the OEM radio and CB on both my TJs.
Do you guys still use CB radios?
- Thread starter JeepDew
- Start date
I'm probably going to get my ham ticket and install one of those too. Might as well cover all the bases. I refuse to get a smartphone though!
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I'm sure that somewhere, sometime, some smartphone dweeb will want to do a trail ride using text!
I think that I've met people from that generation, but I don't think any of them would own a TJ. Not enough built-in computerized shit.
Besides, they can watch a You Tube or Instagram video and don't need to do a real trail ride at all.
TJ2
TJ Expert
Could you imagine a drunken 21 year old driver doing rock crawling while texting and getting some likes in the instagram?
abruzzi
Member
As I mentioned, choice one is to use the system that the people you want to talk to use. That being said, there are a number of good reasons why, on a technological level, CB sucks. The first is the frequency of the CB channels (in the US) puts it at approximately 11 meter wavelength. The simplest and most effective omnidirectional antenna is a dipole, which is 1/2 of the wavelength—5.5meters in the case of CB. Of course a 5.5meter antenna is completely impractical. Vehicles will frequently use half a dipole, so 1/4 the wavelength, with the metal RF ground of the vehicle creating a phantom half of the antenna. But even 1/4 of 11 meters is 2.75 meters, or 108 inches. Even that is impractical on many vehicles, so you get 2, 3, or 4 foot antennas where a wire is wrapped around a fiberglass core, or a coil is placed inline in order to get the antenna close to useful. In the ham world, 11 meters is considered “high frequency” or HF, and setting a vehicle up for good quality HF is really difficult. This is why handheld CB are borderline worthless, because the antenna is such a compromise.
if you do all the same calculations for GMRS, which is near the 70cm ham band. So, half wave is 35cm, and quarter wave is 17.5 cm. That is a nice, small antenna, and still an excellent radiator. 2m, which is a ham band but the free MURS bands are close by, also have simpler, relatively short antennas.
the other big drawback is that for the most part, CBS uses AM modulation (you can use SSB modulation on CB, but almost nobody uses it.). Amplitude modulation is horribly inefficient (3/4 of the power is spent transmitting unnecessary parts of the signal—the carrier signal and the lower side band). AM is also much more susceptible to interference (just tune an AM broadcast station and compare it to an FM broadcast station.)
the point being that there are a number of choices in the CB specifications that make it much less practical. If you need to talk to someone that only has CB, then get a CB, but (IMO) CB can’t die soon enough. MURS or FRS if you don’t want the cost and hassle of licensing, GMRS if you don’t mind paying $80 every ten years, and ham if you want more flexibility. (And I’ll say, the technician test is easy—ignore the math and technical questions, you can miss them all and still pass. The policy questions are mostly self evident.)
if you do all the same calculations for GMRS, which is near the 70cm ham band. So, half wave is 35cm, and quarter wave is 17.5 cm. That is a nice, small antenna, and still an excellent radiator. 2m, which is a ham band but the free MURS bands are close by, also have simpler, relatively short antennas.
the other big drawback is that for the most part, CBS uses AM modulation (you can use SSB modulation on CB, but almost nobody uses it.). Amplitude modulation is horribly inefficient (3/4 of the power is spent transmitting unnecessary parts of the signal—the carrier signal and the lower side band). AM is also much more susceptible to interference (just tune an AM broadcast station and compare it to an FM broadcast station.)
the point being that there are a number of choices in the CB specifications that make it much less practical. If you need to talk to someone that only has CB, then get a CB, but (IMO) CB can’t die soon enough. MURS or FRS if you don’t want the cost and hassle of licensing, GMRS if you don’t mind paying $80 every ten years, and ham if you want more flexibility. (And I’ll say, the technician test is easy—ignore the math and technical questions, you can miss them all and still pass. The policy questions are mostly self evident.)
That's all true enough - BUT - CB works just FINE for short haul comms, which is what it was created for. Like a string of Jeeps on a trail.
(And I’ll say, the technician test is easy—ignore the math and technical questions, you can miss them all and still pass. The policy questions are mostly self evident.)
I find the opposite to be true for the Ham Tech license myself - the tech stuff is easy, but the policy stuff is a bit harder! Regardless, my Jeep will have all 3 fairly soon: they're all small and cheap enough so why not?
(And I’ll say, the technician test is easy—ignore the math and technical questions, you can miss them all and still pass. The policy questions are mostly self evident.)
I find the opposite to be true for the Ham Tech license myself - the tech stuff is easy, but the policy stuff is a bit harder! Regardless, my Jeep will have all 3 fairly soon: they're all small and cheap enough so why not?
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You apparently wheel in different terrain than I and others do. In very steep, mountainous, forested terrain where vehicles in the group are often seperated by many hundreds of yards and hundreds of feet of elevation the CBs are not always "Fine". Yet a crappy little Baofeng UV5R with its rubber duck antenna generally works beautifully. A real high power onboard radio is even better.
I agree with everything you say but there is one additional factor. Path loss at GMRS frequencies is about 25 dB higher than at CB frequencies. Admittedly, free space path loss may not often be the limiting factor, but it sort of scales in other circumstances like a high multi-path environment. About 10 dB of that loss can be made up if everyone is using 40 Watts, and maybe a few more dB by using the higher gain, more efficient antennas that are possible for GMRS. Also, atmospheric noise is less at GMRS frequencies. I suspect that GMRS is better, all things considered, given the better modulation, lower noise and less waste of transmit power and bandwidth.
Also true - but we were discussing GMRS vs CB. CB's main limitation is its anemic power output.
This is becoming much too complex.
Many of my offroading friends use CB so I have a CB.
I have many other offroading friends who are hams so I too am a ham.
I am making new offroading friends with GMRS radios so I acquired a GMRS radio as well.
Simple.
Many of my offroading friends use CB so I have a CB.
I have many other offroading friends who are hams so I too am a ham.
I am making new offroading friends with GMRS radios so I acquired a GMRS radio as well.
Simple.
TJ2
TJ Expert
Damn. I could imagine 3 radios, yours might look worst than this:
I’ve got three radios and I don’t even have GMRS.... yet.
TJ2
TJ Expert
CB is like the VHS and/or turn table in my time.
Will add value to a classic dinosaur.
I have two radios installed now, but maybe you're right. To fit three I think I might need to go smaller.
For the top of the Arizona Rocky Road mounting bar I'm thinking of buying a President Bill CB (4.02 W x 3.94 D x 0.98 H) to be mounted next to a Midland MXT275 GMRS (5.25 W x 5 D x 1 H), with my spare Yaesu FT-90R dual band ham radio put back into service and centered underneath (3.9 W x 5.4 D x 1.2 H).
Its organizing the mics that will be the challenge.
MikeM
TJ Enthusiast
You might try this for the CB it works well for me I can not tell any difference in transmit/receive and yes that is the entire cb hooked up to a rear mount 3 foot firestick Have had almost 6 miles line of sight rx/tx. It is held in place with Velcro to the side of the emergency brake housing easy to access but out of the way,
The one next to the CB is 2M/440. The one on the dash is HF and 6M.
Looking at putting a GRMS radio in my Jeep. Is there a reason I can't use my CB antenna mount for the GRMS as well? This might a stupid question, but if I wired up my GRMS to power and simply switched the coax cable from the CB to the GRMS, would it work? I'm seeing a lot of magnetic antenna mounts instead of what I'm used to with the regular CB antenna mount. I'd rather only run one antenna on my Jeep if possible since I doubt I'd use both radios at one time for my uses.