GMRS as an alternative to CB or 2m?

[Mashurst]

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.

The reason I rate it lower is that the equipment typically used is so poor when compared to the HAM equipment and the fact that more power is available if needed to make contact. I concede that the frequencies are so close as to be considered the same as far as how they will work IF everything ells is the same. But in that IF lies the argument. The UHF HAM in my rig will do 35 watts on high if I remember right, and yes that can be the difference between making a contact or not. Most of the buddies have at least that much power and we all run external high performance antennas that have been set up by people that know what they are doing more or less. This is the typical HAM setup but would be very uncommon for GMRS.
Thus the useful range is based on the typical equipment. For GMRS that is a bubble pack radio with maybe 10 watts and a built in antenna. While there is better stuff on the market it is the exception not the rule. In order to communicate you need that other end of the conversation so even if you get a sweet GMRS setup. Finding anyone that can talk to you from farther than a few miles is a long shot to put it generously.
I have made contacts simplex with UHF at almost 200 miles, but I didn't put that number in the chart because it is not within what I would call "useful range" for a mobile setup. It was from a mountain top with a directional antenna. Toss in a sat. pass and you could double that, but there again its not what we are talking about.

 

[hochung]

if you get a hold of an all mode transceiver, try the 2m SSB. it's fun.


I've never done 1000+ miles, but I've had 2m SSB work where 2m FM didn't.

 

[Mashurst]

I've had 2m SSB work where 2m FM didn't

...and if you had good enough eyes you could have seen him right? since its only good for line of site? Just kidding. Ya 2m SSB is very cool. I have done a bit of it, but it was on a loaner radio.

 

[hochung]

...and if you had good enough eyes you could have seen him right? since its only good for line of site? Just kidding.

line of sight only? You sure?

 

[Mashurst]

I was just poking fun. People like to say VHF and UHF are only line of site and my experiencing shows otherwise. You may not be able to hit Tokyo or Sidney or Southamanian, but it will walk over hill and dale.

 

[bugnout]

The reason I rate it lower is that the equipment typically used is so poor when compared to the HAM equipment and the fact that more power is available if needed to make contact.

Understand:ylsmoke: That really is the misconception most have about GMRS. I have maybe $130 in my Motorola SM120 40 watt mobiles and antenna. You can find some decent 4w handhelds from Midland and Motorola for about $20-30 apiece. Commercial used 5w handhelds (Motorola Spirit or Radius) run $50 on up on fleabay.

Very easy to outfit yourself with mobiles and portables with used commercial grade equipment, and I view a unique upside of GMRS is you can find high quality bubble pack radio's, something you can't find in 70cm, 2m or pretty much any other band.

We were originally talking about 2M vs GMRS, which I think we all agree is superior in range for emergency communication and better range in general than UHF. 420-450MHz and 450-470MHz are pretty much the same performance, same quality equipment. IMHO there are other real advantages to GMRS that have already been stated. Its all in your perspective.

 

[Mashurst]

Is it leagle to use radios that are not sold (aproved) as GMRS? I thought not but maybe that was based on FRS.

 

[Alchemyguy]

Understand:ylsmoke: That really is the misconception most have about GMRS. I have maybe $130 in my Motorola SM120 40 watt mobiles and antenna. You can find some decent 4w handhelds from Midland and Motorola for about $20-30 apiece. Commercial used 5w handhelds (Motorola Spirit or Radius) run $50 on up on fleabay.

Very easy to outfit yourself with mobiles and portables with used commercial grade equipment, and I view a unique upside of GMRS is you can find high quality bubble pack radio's, something you can't find in 70cm, 2m or pretty much any other band.

We were originally talking about 2M vs GMRS, which I think we all agree is superior in range for emergency communication and better range in general than UHF. 420-450MHz and 450-470MHz are pretty much the same performance, same quality equipment. IMHO there are other real advantages to GMRS that have already been stated. Its all in your perspective.

...which is fine if you're a dweller of the US *and* get the rest of your crew to play along. The rest of us don't (legally) have access to anything but 2W handhelds with permanent antennae, or something very much like it. So that leaves us with 2M, which blows that option out of the water without any real question and is already well accepted by travellers all over the world as the comms de rigueur.

I won't argue that it's a bad choice for you and your crew; if you rock out carrier pigeons that's awesome for you. It is, however, a terrible choice for just about everybody else in the world that needs inter-vehicle comms.

 

[Alchemyguy]

Is it leagle to use radios that are not sold (aproved) as GMRS? I thought not but maybe that was based on FRS.

I'm not an expert, but every other service I've bumped into prohibits transmitting on radios not approved for that service/band/whatever.

 

[bugnout]

Is it leagle to use radios that are not sold (aproved) as GMRS? I thought not but maybe that was based on FRS.

Like all other services, the radios need to be part 95A type-certified. Many Part 90 used commericial grade radios are also type-certified for GMRS. need to check the FCC database with the model number. Basically the radio needs to be narrow band FM 450-470MHz, less than 50w and can't have any features that are specifically prohibited in the GMRS rules.

 

[bugnout]

It is, however, a terrible choice for just about everybody else in the world that needs inter-vehicle comms.

Agreed. Very useful within the US, not legal anywhere else.

 

[rugbier]

Bringing up the death *LOL*

I have posted month ago I have purchased this Motorola SM120 ( 450-470 Mhz ) 25w 16 channels , and asked for a decent antenna ( well I've never got around to install it )

Now I have an Yaesu 2800 2M, and was wondering if there is a single antenna that could be used / shared with both radios ?

( I am trying to avoid making my Defender look like a Ghostbuster looking truck full of antennas as I lready have a Firestick for the CB )

Thanks in advance

 

[1911]

Bringing up the death *LOL*

I have posted month ago I have purchased this Motorola SM120 ( 450-470 Mhz ) 25w 16 channels , and asked for a decent antenna ( well I've never got around to install it )

Now I have an Yaesu 2800 2M, and was wondering if there is a single antenna that could be used / shared with both radios ?

( I am trying to avoid making my Defender look like a Ghostbuster looking truck full of antennas as I lready have a Firestick for the CB )

Thanks in advance

Sure, a dual-band 2M and 70 cm antenna would work fine; the 70 cm amateur band (420-450 MHz) is right next to your Motorola commercial radio band, close enough to work well. But you'd need a duplexer to hook two radios into one antenna. Most people who wanted to do this would probably just buy a dual-band radio in the first place - then you'd have less clutter inside the truck too.

 

[rugbier]

Sure, a dual-band 2M and 70 cm antenna would work fine; the 70 cm amateur band (420-450 MHz) is right next to your Motorola commercial radio band, close enough to work well. But you'd need a duplexer to hook two radios into one antenna. Most people who wanted to do this would probably just buy a dual-band radio in the first place - then you'd have less clutter inside the truck too.

I have asked that question ( even here ) and was told " No GMRS / HAM radios in the USA "

 

[1911]

I have asked that question ( even here ) and was told " No GMRS / HAM radios in the USA "

That's true. Sorry, I should have been more specific: most people would probably just buy a dual-band ham radio (2m and 70cm) in the first place - but most ham operators don't have much use for GMRS for the reasons already stated in this thread.

Nevertheless, if you're bound and determined to have both then an antenna resonant on 70 cm should still be easily close enough to use on 450-470 MHz.