Just like every other band in ham radio, the 70 centimeter band also has it's own band plan. Similar to 2 m, 70 cm sections of the band allocated to things such as EME, weak signal, satellites, repeaters and simplex. The FCC has allocated 420 MHz to 450 MHz for amateur radio. Unlike 2 m, there is no section of the 70 cm band set aside for only CW.
Below we have the ARRL band plan for the 70 cm segment of the spectrum. Just like 2 m, there is space in the band for a little bit of everything.
ARRL Band Plan
| 420.00-426.00 | ATV repeater or simplex with 421.25 MHz video carrier control links and experimental |
| 426.00-432.00 | ATV simplex with 427.250-MHz video carrier frequency |
| 432.00-432.07 | EME (Earth-Moon-Earth) |
| 432.07-432.10 | Weak-signal CW |
| 432.10 | 70-cm calling frequency |
| 432.10-432.30 | Mixed-mode and weak-signal work |
| 432.30-432.40 | Propagation beacons |
| 432.40-433.00 | Mixed-mode and weak-signal work |
| 433.00-435.00 | Auxiliary/repeater links |
| 435.00-438.00 | Satellite only (internationally) |
| 438.00-444.00 | ATV repeater input with 439.250-MHz video carrier frequency and repeater links |
| 442.00-445.00 | Repeater inputs and outputs (local option) |
| 445.00-447.00 | Shared by auxiliary and control links, repeaters and simplex (local option) |
| 446.00 | National simplex frequency |
| 447.00-450.00 | Repeater inputs and outputs (local option) |
EME & ATV
At the beginning of the band, we have a section dedicated to EME as well as ATV. Now this isn't for use with all terrain vehicles, this ATV is Fast-Scan Amateur TV. What can you do with ATV you ask? Using ATV you can send video signals from model airplanes or rockets or even a remote camera so long as you have line of sight. In addition to EME and ATV, there is space set aside for weak signal work as well as propagation beacons.
Satellite
Just as with 2 meter, there is the ability to work OSCAR, or Orbiting Satellite Carrying Amateur Radio. Interference creates an issue with satellite work as typical ground communications can easily overpower a week signal being received from space.
FM Repeater & Simplex
A good chunk of the 70 cm band is set aside for repeaters and simplex. As we saw with 2 meter, once again there are "channels" across this portion of the band. Repeater links will typically have a 12.5 kHz spacing while repeaters themselves and simplex is typically spaced at 25 kHz.
To use a 70 cm repeater, you'll need 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 -5 MHz, or +5 MHz, 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.
When it comes to simplex, or talking to people that are close by using just one frequency, the channel spacing is also 25 kHz depending upon your region. The National Calling Frequency for 70 cm is 446.000 MHz. There aren't as many channels when it comes to 70 cm simplex as there are for 2 m simplex. What has been adopted locally will play into what range of frequencies you have available to you for simplex. Since I'm in Texas there is the Texas Band Plan that needs to be followed. This provides for the simplex channels listed below.
| 25 kHz Spacing |
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Crossband Repeat
Crossband repeat is a feature found in some mobile radios. It allows the radio to receive a transmission on one frequency, and retransmit it on another. A good use case for this would be taking a handheld (HT) radio out on a hike while your mobile radio in your car is set to crossband repeat. When you transmit on your HT, it is received by the mobile in your car, and retransmitted. This effectively turns your 5 watt HT into a 50 watt radio allowing you to hit repeaters that you might not otherwise be able to reach with your HT while on your hike. In Texas we have the following frequencies/channels for crossband repeat.
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Crossband Repeat 25 kHz Spacing |
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Summary
While there is a lot to the 70 cm 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 or crossband repeat, 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.