Below is another guest article from Justus at Centerfire Antenna. If you have an interest in HAM radio’s or 2 way communication – contact these guys – they know their stuff.
IMO, every household should have at least one pair of the retail store GMRS/FRS “Bubble Pack” radios
and here’s why:
1) They’re easy to use, meaning that almost everyone can pick one up and use it without extensive instruction.
2) They’re an inexpensive way to communicate in a neighborhood environment.
3) Due to their price and popularity, a large percentage of the population have them
(including the bad guys).
These radios are usually advertised as GMRS/FRS.
(General Mobile Radio Service and Family Radio Service)
Right now, there are about 6 different brands and, from what I can determine,
Cobra, Midland and Motorola dominate the market.
I’m going to attempt to describe in detail the common features found on these radios.
The last seven features (in bolded italics) are what I consider to be the most valuable.
This actually means 22 actual frequencies. For some reason when a radio
is mass-marketed, the frequencies are numbered and designated as “channels”.
Of the 22 channels only 8 of them are truly GMRS frequencies and are programmed to operate at the
radio’s maximum power or the user can usually reduce power if wanted.
On Midland and Motorola radios the channels 15-22 are true GMRS.
You may actually hear commercial traffic here.
Higher powered GMRS users will use these frequencies for repeaters.
Bubble Pack radios cannot be used on repeaters at this time. They are not repeater capable
The remaining channels are divided as follows:
- 8-14 are FRS-only frequencies and will be programmed at low power per FCC rules.
- 1-7 are shared FRS/GMRS frequencies, mainly designated for family use and will be programmed at the radio’s maximum power or the user can usually reduce power if wanted.
CTCSS, DCS and Privacy Codes:
This is one of the features that the mfgrs advertise the most and is most confusing to the consumer.
Many claim 142 or more channels, this is false. What this feature does is set
YOUR radio to filter all the incoming signals that aren’t using a specific tone. This is handy in a crowded setting like
malls, campgrounds etc where another group may be using your frequency but your group
doesn’t want to hear them.
ALL codes are standard and numbered but they may be arranged differently by the different mfgrs.
Midland and Motorola use the same numbering system but Cobra has rearranged some of the numbers.
Note: Recently I’ve seen 2 mfgrs offer a limited supply of their radios with voice scrambling.
This is different than privacy codes because it is a proprietary process. Each mfgr uses a slightly different method of scrambling.
They are being marketed prior to FCC approval.
The FCC has definitely frowned on this in the past and I truly believe that these radios
will be pulled from the market. It’s a very unusual feature that I think could come in handy so
if you get the chance to buy a set I’d do it. (Midland GXT900)
This allows a hands free operation of your radio.
Basicly, the radio keys up when it hears a noise. Good feature for baby monitoring but can be frustrating
since it’s hard to use without practice. The first few words are often not transmitted or the radio keys up when
there is other noise in the background.
Roger beep is simply a “beep” to indicate that you have finished your transmission.
Personally, I think this feature is very annoying and will give away your location if you’re trying
not to be noticed, I usually disable it.
This feature is fairly new and allows “direct calling” to a specific radio by using ID codes and group codes.
I’ve never used it, it seems like a nice feature but be careful of the ring tones, they’re loud.
Very nice feature if you spend alot of time outdoors.
This is IMO the most important thing to consider in purchasing a Bubble-Pack radio.
The actual minimum antenna length required at the GMRS/FRS frequencies is 6 inches (approx).
You’ll notice that many of these bubble-pack radios have antennas that are barely 2 inches tall.
There is absolutely no way to make an efficient GMRS antenna that is only 2 inches tall.
The manufacturers are simply making the radio less prone to antenna breakage by shortening the antenna.
Look for the radio with the longest antenna.
The number of batteries required is very important. The more batteries the better.
This means the radio has more available power to operate, and/or will operate longer on a set of batteries.
Motorola uses 3 AA and Midland GXT uses 4 AA, both of these radios advertise a range of 10 miles or more.
Older Cobra radios use 8 AA batteries and advertised 2 miles.
Very handy feature. I see this as a must have in my radios.
Like I said before, these are very popular and I do believe that bad guys can and
will be using these radios. Having one scanning during the bad times could alert you to
something going on nearby.
External Speaker Mic:
Another must have IMO. In fact, be sure that a speaker mic is available for the radio before you buy it.
This will allow you to anchor the radio to your belt or vest with the antenna vertically positioned and
allow you to keep the speaker in or near your ear so the volume can be reduced.
Very nice feature, especially if you have some folks in your group that like to fiddle with things.
This keeps the radio settings from being accidentally changed.
Very nice feature to limit your transmission range if necessary.
So to sum it up:
1) Most radios have 22 specific frequencies, numbered as channels.
2) All radios have the same channels, and privacy codes but they may be arranged differently by mfgr.
3) All radios use some low power FRS channels
4) Antenna length is very important, short is bad. Try to find a radio with the longest antenna possible.
5) The more batteries the better.
6) Voice scrambling is great, but I don’t see it getting past the FCC, so get ‘em while you can.
7) 142 Privacy codes does not mean you have 142 channels
The transmit range of the current bubble pack radios is 2 miles max at ground level in average wooded terrain.
Less in dense urban settings or hilly areas.
I’ve heard about some getting outstanding distance in flat unobstructed areas (Iraq) but that is an exception.
As always, no matter which equipment you decide to get: learn how to use it and use it regularly.
© 2010, Rourke. All rights reserved.