70 cm Band Guide: Repeaters, Satellites and Propagation on 430 MHz

Most handheld radios sold today cover two bands, and the second of them is the 70 cm band. It is the band of the local UHF repeater, of the digital voice hotspot in the corner of the shack, of the uplink to many amateur satellites and of some surprisingly long tropospheric contacts. It is also a band whose edges, sharing arrangements and sub-band plans differ more from country to country than almost any other, which is why so many newcomers are unsure what they may do on it. This guide sets out the allocation, what the band is used for, how signals behave at 430 MHz, which antennas and feedlines make sense when every metre of coax costs more than on HF, and how to get the most out of the band from a handheld to a weak-signal station.

Where the Band Sits

The 70-centimeter band reference page summarises the allocation. The ITU amateur allocation is 430 to 440 MHz, and that is what amateurs in the United Kingdom and Ireland have. Some countries allocate more: the United States has 420 to 450 MHz with some geographical limitations, and Canada and Australia have 430 to 450 MHz. In many countries the band is shared with other services and amateurs are secondary users; in the United States the sharing partner includes government radar systems, and near the Canadian border operation in the lower part of the US allocation is restricted. In Europe the band is shared and local restrictions apply in parts of some countries. The practical lesson is to read your own national band plan and licence conditions before transmitting, and to expect the repeater and simplex frequencies in one country to differ from those in the next.

Within the allocation, the IARU regional band plans set aside segments for beacons, weak-signal CW and SSB, satellites, repeater inputs and outputs, simplex channels, digital voice and data. The IARU Region 1 band plans are the reference for Europe, Africa and parts of Asia, and the national societies publish the channel lists that sit inside them. Our overview of IARU band plans by region explains how the three regions relate.

What People Do on 70 cm

Repeaters and Simplex

For most operators the band begins with a repeater. UHF repeaters use a fixed offset between input and output, with a value set by the national plan, and most require a CTCSS tone or a digital code to open. The operating habits are the same as on 2 metres: listen first, give your callsign, keep overs short and leave a pause between them so that others can break in. Our guide to VHF and UHF simplex and repeater operating covers the etiquette in detail. Because UHF signals penetrate buildings differently from VHF, a 70 cm repeater is often the better choice inside a city, where reflections off buildings fill in the shadows, while a 2 metre repeater may reach further across open country.

Simplex on 70 cm is underused in many areas. The designated simplex channels are a good place for a local chat without tying up the repeater, and the shorter wavelength makes a small directional antenna practical, so two stations a few kilometres apart can often talk reliably with modest gain antennas where the handheld whips cannot.

Digital Voice and Hotspots

The three main digital voice systems all live on 70 cm as well as 2 metres, and in many regions the UHF band carries most of the digital traffic. The personal hotspot, a tiny simplex transceiver connected to the internet, is almost always set up on a 70 cm simplex frequency chosen from the digital segment of the local band plan, and it links a handheld in the house to talk groups and reflectors around the world. Choosing the frequency carefully matters: it must be inside the segment the plan designates, away from repeater inputs, and clear of the satellite segment, which hotspots have been known to interfere with. Our comparison of DMR, D-STAR and System Fusion explains the systems themselves.

Satellites

Many of the amateur satellites in low Earth orbit use 70 cm for one direction of the link, paired with 2 metres for the other. The simplest FM satellites can be worked with a dual-band handheld and a small hand-held Yagi, pointing the antenna at the satellite as it passes and correcting for Doppler shift on the 70 cm side, where the shift is several kilohertz across a pass and cannot be ignored. The linear transponder satellites need an all-mode radio and full-duplex operation, so that you can hear your own downlink while transmitting. The satellite segment of the band is reserved for this use, and a hotspot or a simplex chat in the segment can wipe out a pass for everyone within range. Our getting started with amateur satellites guide walks through the first FM pass.

Propagation on 430 MHz

Signals on 70 cm travel in nearly straight lines and are affected by terrain, buildings and foliage more than on 2 metres. The usual range is line of sight plus a little, which is why repeater sites on hills and towers dominate the band. Three mechanisms extend it.

Tropospheric enhancement and ducting

When a layer of warm dry air sits above cool moist air, typically under a high-pressure system, signals bend along the boundary and can travel hundreds or even more than a thousand kilometres. The effect is stronger on 70 cm than on 2 metres, and the band’s weak-signal operators watch the weather charts for these conditions. A tropo opening across a sea path can bring repeaters from another country into a handheld, and it can give a modest SSB station contacts it would normally never make.

Aircraft scatter

Aircraft reflect UHF signals well, and a station with a beam can make brief contacts over several hundred kilometres by timing transmissions to a passing aircraft on the path. Digital modes designed for short bursts suit this.

Moonbounce

Earth-Moon-Earth contacts are a specialist pursuit, but 70 cm is one of the most active EME bands because the antennas needed are smaller than on 2 metres for a given gain, and digital modes have made it reachable with a single long Yagi and a few hundred watts.

What the band does not have is any regular ionospheric propagation. Sporadic E reaches 2 metres a few times each summer in a good year and essentially never reaches 70 cm, so the band’s DX comes entirely from the weather and from the sky.

Antennas and Feedlines

A quarter-wave on 70 cm is about 16 centimetres, so antennas are small and gain is cheap. A vertical collinear for FM, a Yagi of a dozen elements for weak-signal work or a small hand-held Yagi for satellites all fit on a balcony or a short mast. The J-pole and ground plane designs described in our 2 meter antenna guide scale directly to 70 cm, and many commercial verticals are built for both bands. Polarisation matters more here than on HF: FM and repeaters are vertical, weak-signal SSB and CW are horizontal, and a mismatch costs a large fraction of the signal, so a station that does both needs two antennas or a switchable arrangement.

The feedline is the trap. Loss in coax rises steeply with frequency, and a cable that is fine on HF can swallow half the power or more on a long run at 430 MHz. Keep runs short, use low-loss cable, and put the money into the feedline before the amplifier. Our coax comparison gives the loss figures by type; on 70 cm the difference between thin and thick cable over a twenty-metre run is dramatic. Connectors matter too: N-type connectors are the standard at UHF, and a poorly fitted connector introduces loss and intermittent faults that are invisible at HF.

Getting the Most From the Band

• Program the local repeaters properly, with offset and tone, and the simplex and digital channels from the national list.
• Get the antenna outside and up. On UHF, a modest antenna in the clear beats a large one indoors by a wide margin.
• Try the weak-signal segment during contests and tropo openings. An all-mode radio and a small horizontal Yagi open up a different band.
• Watch the weather for tropo. A stable high-pressure system, especially over water in autumn, is the signal to point the beam toward the coast.
• Respect the satellite segment. Keep hotspots and simplex chats out of it.
• Work a satellite pass. A handheld and a hand-held Yagi are enough for the FM birds and it is one of the most satisfying things the band offers.

Setting Up a First 70 cm Station

A sensible first station is a dual-band mobile radio of modest power at home, fed from a regulated supply, with a dual-band vertical on the roof or a pole and a short run of good coax. That covers the repeaters, simplex and, with a hotspot, the digital networks. The handheld then becomes the portable companion rather than the main station, and the difference in what you can hear and work is immediate. Program the radio from the national channel list rather than by hand, so that offsets and tones are right the first time, and label the memories so that you can tell a repeater from a simplex channel at a glance.

The second stage, if the weak-signal side appeals, is an all-mode transceiver that covers 70 cm, a horizontally polarised Yagi on a rotator, and a mast-mounted preamplifier to make up for the feedline loss on receive. At that point the band changes character: the contests, the tropo openings and the satellites with linear transponders all become available, and the handheld-and-repeater world looks like the small corner of the band it really is. Keep the vertical for FM, because switching between the two polarisations on one antenna is not practical, and feed each antenna with its own short low-loss cable.

The Bottom Line

The 70 cm band is where UHF amateur radio happens: local repeaters and simplex, the digital voice networks and their hotspots, the uplinks and downlinks of the satellites, and a weak-signal community that waits for the weather to deliver DX. Its allocation differs by country, so learn your own plan, keep the hotspot out of the satellite segment, put the antenna in the clear, and spend on low-loss feedline rather than power. Do that and the band rewards you from the first repeater contact to the first satellite pass and, if you stay with it, the first signal off the Moon.

Frequently Asked Questions

What frequencies are in the 70 cm band?

The ITU amateur allocation is 430 to 440 MHz. Some countries have more, such as 420 to 450 MHz in the United States and 430 to 450 MHz in Canada and Australia, with local restrictions. Check your national band plan.

Is 70 cm better than 2 meters?

Neither is better in general. UHF signals handle buildings and reflections well in cities and allow smaller antennas with more gain; 2 metres often reaches further over open country and has sporadic E openings that 70 cm does not.

How far can you talk on 70 cm?

Line of sight plus a little for simplex, tens of kilometres through a repeater, hundreds or more than a thousand kilometres during tropospheric ducting, and to the Moon and back for a well-equipped EME station.

Which coax should I use for 70 cm?

Low-loss cable with N-type connectors, kept as short as possible. Thin HF-style cable loses a large fraction of the power over any significant run at 430 MHz.

Can I use a handheld for satellites on 70 cm?

Yes, for the FM satellites, with a small hand-held Yagi and manual correction of the Doppler shift on the 70 cm side of the link.

Why should hotspots stay out of the satellite segment?

Because a hotspot transmitting in the satellite sub-band interferes with everyone within range trying to work a pass. Band plans designate separate digital voice channels for hotspots.