xtatik
Explorer
Thanks, .02 cents is about right.
GMRS as an alternative to CB or 2m?
- Thread starter Martinjmpr
- Start date
Thanks, .02 cents is about right.
hochung
Adventurer
more like 0.00.
That's interesting indeed. I bet if you set your 2m radio to 146.520MHz, it'll be the same 146.520MHz on my 2m radio.
Michael
Adventurer
There are a lot of misconceptions about what the GMRS service and FRS service are and what they are not. Here is a very good FAQ on the difference between GMRS and FRS and the requirements for their use. Most people don't realize it, but if their inexpensive hand-held "FRS" radio provides shared GMRS and FRS channels, it has been "type approved" for GMRS and therefore falls under GMRS regulations. In other words, the FCC considers FRS/GMRS radios to be GMRS radios for the purpose of regulation. Those who use the so-called "hybrid radios" without a license are known as 'Bubble Pack Pirates" and are causing a lot of problems for legitimate GMRS users. Under FCC regulations, ALL GMRS users are required to have a license issued by the FCC. Hand-held radios that provide ONLY FRS channels can be used without a license (I don't ever recall seeing this type of radio for sale) and FRS radios are limited to 1/2 watt of power transmitted through the installed stub antenna. For those evaluating use of GMRS radios on the trails, I highly recommend reading this article.
GMRS, FRS, Ham (Amateur Radio Service), MURS, etc are 'services' defined by the FCC and have different purposes and regulations. Each service is set aside for a specific use within the radio frequency band and each has regulations to prevent interference between users of all services. It isn't about which service is better, it's about which service better suits your intended purpose.
GMRS, FRS, Ham (Amateur Radio Service), MURS, etc are 'services' defined by the FCC and have different purposes and regulations. Each service is set aside for a specific use within the radio frequency band and each has regulations to prevent interference between users of all services. It isn't about which service is better, it's about which service better suits your intended purpose.
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xtatik
Explorer
Tryin', but there are some gross misconceptions and misinformation being flung in this thread. I really would hate to see people head off in the wrong direction.
rugbier
Adventurer
bugnout
Adventurer
Passed the tech exam, 100%, they let me take the general exam as well, need to do a bit more studying. :sombrero:
Nice table, good summary, I'm not sure I agree that HAM UHF (70cm) has that much additional range. I'm new to this, but haven't read anywhere that 420-450MHz has that much of an advantage over 450-470MHz Both are pretty much line-of-sight bands, rarely skip, Very good for in building coverage and penetration.
For UHF, Range has less to do with power than height of the antenna, Repeaters in either band will propagate to the radio horizon. 5-10 watts is all the power you need.
Nice table, good summary, I'm not sure I agree that HAM UHF (70cm) has that much additional range. I'm new to this, but haven't read anywhere that 420-450MHz has that much of an advantage over 450-470MHz Both are pretty much line-of-sight bands, rarely skip, Very good for in building coverage and penetration.
For UHF, Range has less to do with power than height of the antenna, Repeaters in either band will propagate to the radio horizon. 5-10 watts is all the power you need.
cruiseroutfit
Well-known member
Hang out with a better crowd. On some of our larger trips (20+ rigs such as the Cruise Moab Swell runs) we are hitting over 50% of the group having 2M, and when we are getting spread out 5+ miles in canyon country, CB's are useless. When we are choosing trail leaders, gunners and tail crew the first thing that comes into play is communications and 2M being the priority. We had a run last year (Utah Cruiser Expedition II) in which 100% of the group had 2M and I have to say it resulted in a lack of frustration normally experienced by bad coms with groups.
Now, I do trail guiding and off-road training for a local motorsports facility (Miller Motorsports Park for those in Utah), we have a fleet of JK's we are often out on the trail with, often with folks that have never been behind the wheel of a 4x4 so communications are vital. We use commercial handheld GRMS radios and while at the park with the repeaters functioning they are fabulous, when we get out to the desert and have to switch to a radio to radio (simplex mode) they get a mile or so at best in the canyon topography, even a CB would be a better option
How do you figure? Besides ScenicWonderRunner's CB, the rest of ours are good for 5 miles max
My 2M ham is good for 10+ on simplex even in steep topography.Some good discussion here:
http://www.expeditionportal.com/forum/threads/384-Best-CB-set-up?highlight=radio
xtatik
Explorer
Good job getting the Tech. You should share how miserably difficult it was to get your license with this group.:coffeedrink:
Given the same power, I'd probably agree on your points regarding simplex distances twixt the two UHF segments. But, I don't agree on your point concerning power needed to reach across distances. Certainly, altitude helps, but their is no propogation taking place once the RF leaves the antenna on FM. With FM power is much more important than with HF. In fact, when broadcasting across flat terrain.....it's all you've got.
Also, speaking freely about the availability of bubble-pack repeaters is very misleading. At this point, and when speaking to this type of audience, IMO it's best to assume they don't exist. When comparing numbers...unlike the Amateur Service, bubble-pack repeaters are nearly non-existent, and they are nearly all private. In most cases, the likelihood of someone from this audience having a bubble-pack repeater available to use on a backcountry trip is nil, nada, fuggetaboutit! Again, it's just my opinion, but I really think it's irresponsible to speak to this crowd about bubble-pack repeaters or the band in general as a fit replacement for the Amateur Service. There is a reason why the FCC requires a license for our service. It has everything to do with power and capability and the operators responsibilities to handle both. The bubble-pack band has little to offer in either.
bugnout
Adventurer
I have a Maxrad PCTEL UHF antenna. Model number MWB4505 on a magnetic mount. Has worked out very well.
http://www.antenna.com/apg_products.cgi?id_num=10932
bugnout
Adventurer
Thanks, it was very easy, but I'm probably not a good example, I'm a computer engineer and just had to dig deep and recall ENG 221, magnetism and waves. I think any reasonably technical person could study for and pass this exam. I think anyone that is good at memorizing questions and answers could study and pass the exam.
From what I've read 420-450MHz (70cm) and 450-470MHz (GMRS range) are not that much different. Without repeaters in the equation they have pretty much the same performance and range. Being line-of-sight bands, 100 watts doesn't go any farther than 50 watts at the same antenna height. That is a lot of power in either band, overkill in my opinion, I haven't done any tests, but if stations are all on the ground, antenna no more than 10 feet high, I think that you will get pretty much the same range from the 5W portables in each band. I was just commenting on accuracy of the table.
I think this is kind of a side track anyway since I think the debate is really, which is more suitable for the kind of activities we all like to do.
Between 2M VHF and either 70cm or GMRS UHF. 2M is clearly superior for long range communications when your trying to contact someone not in your traveling party or when the traveling party could get spread out beyond line-of-sight.
xtatik
Explorer
Actually, this is incorrect, on FM power is critical. Probably the best controlled demonstration of this would be two stations operating while at sea. Two identical antennas at the same height and no obstructions to the horizon. The general rule (safe rule) for FM is "one watt per mile". I'm sure you've heard of this general rule and its application to line of sight communication types. Given this scenario a radio transmitting at 50 watts will travel ten times further as another transmitting at 5 watts.
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