First off, what is the 2 meter band and why is it called that? In the United States, the FCC has allocated 144 MHz to 148 MHz for amateur radio use to those holding a Technician or higher license. Radio operators may use any mode whether it's AM, FM SSB, Data etc between 144.100 and 148.00 MHz. The use of only CW has been restricted from 144.000 to 144.100 MHz. Now why is it called the 2 meter band. This band is called 2 meter because a complete wavelength of 144 MHz is approximately 2 meters long.
Just like most other things in the world, we need to have a plan in order to prevent chaos. Just like the rules of the road for driving, we have the band plan to ensure that the allocation is used properly by everybody. Failure to transmit in the correct mode in for that portion of the band can cause interference in others' transmissions. In order to prevent this the band has been broken up into multiple segments.
As you can see from the table below, the ARRL has segmented the 2 meter band for a number of different activities. These range from the use of FM, CW, EME (Earth-Moon-Earth), repeater inputs and outputs as well as simplex.
ARRL Band Plan
| 144.000-144.050 | EME CW (Continuous Wave aka Morse Code) | |
| 144.050-144.100 | General CW and weak signals | |
| 144.100-144.200 | EME and weak-signal SSB | |
| 144.200 | SSB National calling frequency | |
| 144.200-144.275 | General SSB operation | |
| 144.275-144.300 | Propagation beacons | |
| 144.300-144.500 | OSCAR (Satellite) | |
| 144.500-144.600 | Linear translator inputs | |
| 144.600-144.900 | FM repeater inputs | |
| 144.900-145.100 | Weak signal and FM simplex (145.01,03,05,07,09 are widely used for packet) | |
| 145.100-145.200 | Linear translator outputs | |
| 145.200-145.500 | FM repeater outputs | |
| 145.500-145.800 | Miscellaneous and experimental modes | |
| 145.800-146.000 | OSCAR (Satellite) | |
| 146.010-146.370 | Repeater inputs | |
| 146.400-146.580 | Simplex | |
| 146.520 | National Simplex Calling Frequency | |
| 146.610-146.970 | Repeater outputs | |
| 147.000-147.390 | Repeater outputs | |
| 147.420-147.570 | Simplex | |
| 147.600-147.990 | Repeater inputs |
EME & CW
Starting at the beginning of the band, we have EME and CW. This portion of the band is reserved for Earth-Moon-Earth communications as well as Morse Code. Moving up we have SSB or Single Side Band. This mode is most typically used for longer distances where FM doesn't work as well to achieve longer distance DX communications. The section of the band for propagation beacons is used to send short messages using CW to help determine the propagation of the 2 meter signal. Typically 2 meter VHF is local and line of sight, however when conditions are right, the signal can travel much farther. There have been times where 2 meter repeaters in Hawaii can be picked up along the west coast.
Satellite
Next up is satellite communications using OSCAR or Orbiting Satellite Carrying Amateur Radio. The first OSCAR satellite was launched in 1961 with the most recent satellite, the Nepal-OSCAR 116 being launched in January 2022. Satellites can be difficult to work due to the amount of interreference that they receive because of their altitude and wide line of sight.
FM Repeater & Simplex
The most commonly used portion of the band is FM communications. This portion of the band has been channelized in order to reduce interference. This allows you to talk on one frequency without causing interference to the channels around the one you're operating on. Since the FM signal has a bandwidth of about 16 kHz, channel spacing is typically 15 kHz to 20 kHz wide. Spacing is region dependent so check your state's band plan to determine whether you should be using 15 kHz or 20 kHz spacing. This typically applies to simplex operation.
When it comes to 2 meter repeaters, you will need three bits of information. The frequency, the transmitter offset, and the tone. Frequencies are posted on various club websites as well as repeater directories. The offset will be either -600 kHz, or +600 kHz, depending on where it is located in the band. The tone or PL, is a low frequency tone that is superimposed upon the transmit audio. This tone is used to "wake up" the repeater so that it will retransmit or repeat your transmission. If this tone is missing, then the repeater will ignore your transmission and it won't be repeated.
For simplex operation, or talking to people that are relatively close, only one frequency is used. This is also where the channel spacing of 15 kHz or 20 kHz comes back into play. The standard simplex frequency for North America is 146.520 MHz. This is also known as the National Calling Frequency. If you're in an area that uses 15 kHz channel spacing, the next frequency above the National Calling Frequency would be 146.535 MHz, then 146.550 MHz and so on. If 20 kHz spacing has been adopted in your area, then the next frequency would be 146.540 MHz followed by 146.560 MHz. There are two portions of the band set aside for simplex operation. The frequency allocation is 146.400-146.580 MHz and 147.420-147.570 MHz. Using the proper spacing this gives us 21 to 27 different channels to use for simplex operation. The 2 meter simplex frequencies are listed below.
| 15 kHz Spacing |
|
||||||||||||||||||||||||||||
| 20 kHz Spacing |
|
Summary
While there is a lot to the 2 meter band plan and it seems like it could be complicated at first glance, it's actually quite simple.
- If you're using FM voice, ensure that you're on the proper frequency for the repeater, If you're using simplex, ensure that you're using the proper channel spacing for your area's local band plan.
- Stay out of the SSB, satellite and other weak signal sections unless you're operating in one of those modes.