Reliable - Modern Communications for All of Us...

By Stuart I. Gorsky, K9STU

Having a Amateur Radio Liscense and becoming a "Ham" enables you to enter the world of high quality, long and short range communications geared for personal use (non business) and emergency communications. The downside of getting a "Ham" radio liscense is that each person wanting to use a ham radio needs to pass an FCC exam in order get on the air. The easiest of the three levels of amateur radio licensing is the "Technician" test. This exam has a pool of over 500 test questions to study from and out of this pool there will be thirty five questions asked. (twenty seven is passing) A ham license is good for ten years. (Testing cost approximatly $14.00)

But that is NOT what this article is about! This article is about several quality modes of communication available to the public that do not require a test. Each mode of communications has its good points and bad points and I will try to clear up the differences.


Quick Facts!

  1. All of these radio are FM modulated and under good conditions they sound great! If you have ever heard a police radio you know how these radios sound.
  2. MURS Radios use VHF frequencies (very high frequencies) GMRS and FRS radios use UHF frequencies (ultra high frequencies)
  3. Providing you are using the same power output, both VHF and UHF travel about the same distance but UHF goes through buildings better.
  4. FRS Radio's are limited to 1/2 watt - MURS are limited to 2 watts - GMRS is limited to 50 watts.
  5. All of these radios are "Line of Site". If you can see each other, you can talk to each other. If there are buildings in the way, your communications may only be a half mile to several miles but if one person is standing in a park and the other is on a mountain top 40 miles away you should be able to talk with no problem. More power can be a factor.
  6. Antenna, Antenna, Antena! Having a radio that lets you take off the included rubber duck antenna and connect an antenn with "gain" allows you to greatly extend your range.
  7. On shared radio frequencies you should be using a feature included on all of these radios. It is called DCS or PL. Pick a chanel, select a digital DCS or PL and match the same settings on all of your radios. Now, no matter how many others are on the frequencie you will only hear each other. If others on the frequency complain tell them to get with it and put a DCS code or a PL on there own radios so they too can have uninterupted communications. The manufactures include these features because so many people can share the frequencie at the same time...

FRS

  • Family Radio Service.
  • This is a low power FM service with 14 channels that operates at approximately 462.5 MHz and 467.5 MHz (channel frequencies are in the mid-points between the GMRS frequencies).
  • Maximum power of 0.5 Watts. No separate antenna.
  • Cheapest type of radios. Only handheld sets made.
  • Can be used for business or personal use. No license required.
  • Clean and Clear communications - Very short range

 

GMRS

 

  • General Mobile Radio Service.
  • This is a higher powered FM service with 8 duplex or 16 simplex channels (in theory, but usually only the 8 lower frequency bands are used, the upper 8 are used to transmit to repeaters) that operates at similar frequencies to FRS (around 462.5MHZ plus a matched duplex channel around 467.5MHz).
  • Maximum power of 50 Watts. Can have separate antenna.
  • Also can operate on seven of the frequencies (the 462.5MZ set) used by FRS, with maximum power of 5 Watts (but FRS radios on the same frequencies are limited to 0.5 Watts).
  • Advanced radios can be used with relay/repeater stations to give greatly increased range.
  • For personal use only, not for business use. FCC license required but license covers whole family or all people at transmitter location.
  • High Powered FM quality voice communications - The use of a GMRS Repeater can increase the range to 50 or more miles but in order to do this you generally need to purchase a more expensive high powered mobile radio or a high end handi-talkie manufactured by ICOM or Standard Vertex. Bubble pack radios sold at Best Buy and Wal Mart will not have the ability to work with repeaters. An example of Bubble Pack Radios are the Motorola radios you see being sold in large stores.

 

MURS

 

  • Multi-Use Radio Service.
  • This is the newest of the four services, and is an FM service with five channels operating at approximately 153 MHz.
  • Maximum power of 2 Watts. Can have separate antenna.
  • More expensive than GMRS Bubble Pack Radios (currently) but will probably come down in price as becomes more popular.
  • For business and personal use. No license required.
  • Great Radios for one to three miles communication. A rooftop antenna will increase the range. Best used to communicate with employees in a large facility or out on a farm.

.Frequently Asked Questions about the Multi-Use Radio Service (MURS)

A good web link - http://www.ultimatefrs.com/

Here is the FCC's Web Site for GMRS

Here is the FCC's Web Site for FRS

Here is the FCC's Web Site for MURS

eXtreme Radio Service

 

 

I have been doing some more research and there seems to be a new radio service open to the general public. It's called the eXtreme Radio Service and so far I see only one manufacturer of radios for this service. This is a low powered (1 watt, 900mHz) handheld system that a "group" of users can use to digitally communicate with each other in an encrypted secure manner.


The following is from the manufacturers web site...
----------------------------------------------------------------------

New Digital Technology

eXRS uses Frequency Hopping Spread Spectrum (FHSS) technology and operates in the 900MHz ISM band. The advanced digital circuitry provides superior communications in a small package.

Private and Secure Communications

Prevent eavesdropping and ensure completely secure conversation with TriSquare's integrated digital FHSS technology. Ideal for families with children, groups and business.

*Under the same environmental conditions, the TriSquare eXRS radios usable range is equal to or greater than that of other portable UHF (including FRS/GMRS) 2-way radios.


Regardless of what the manufacturer says, the distance a radio will transmit while on the 900MHz frequency range is very limited. The plus side is that 900MHz radios transmit very well through buildings and the voice quality, at least in analog form is very clear. These radios are digital so not having tested them I cannot comment on how clear and natural sounding the digital voice transmissions are.

Here is the web site for the manufacturer: http://www.trisquare.us/index.html

Here is a web site for a paintball team that uses the eXtreme Radio Service for team communications while in competition. http://www.steelreservepaintball.com/trisquare_exrs.htm

 

TriSquare Radio's Tested...

 

 

 

 

I purchased two of the Trisquare digital eXtreme Radio Service 1 watt, 900 MHz radios and gave them a test. I put one radio in my kitchen in an upright positon with a digital audio recorder running in VOX mode. I walked around my apartment building in all locations at about a 1/4 th mile radius with some directions having a clear line of sight and some locations having many buildings and metal obstructions blocking the radio vave path. For the most part communications were reliable and understandable.

The upside to these radio's is that they are small, reliable and communicate in a secure manner through buildings. The downside is that the radios are cheaply constructed with no mil standard of tuffness and the digital audio was rather poor. The concept is great but I want more professional equiptment...

 

 

Motorola's eXtreme Radio Service - DTR Series

 

 

 

 

Good NEWS! Motorola has there own version of the digital eXtreme Radio Service!

Motorola calls them the DTR Series, Digital On-Site Two-Way Radio's. They start at around $270. but my bet is they are worth it if short range, secure communications are what you are looking for.
Here is a link to Motorola's Digital On-Site Two-Way Radio's.
Motorola DTR series radio .PDF files can be found here.