4 Meter Band (70 MHz): Rules, Propagation and Equipment

Between the busy 6 meter band and the crowded 2 meter band sits a small and often overlooked slice of spectrum: the 4 meter band, centred on 70 MHz. It is available to radio amateurs in only a limited number of countries, commercial equipment for it is scarce and the band is usually quiet, which is exactly why a loyal community of operators loves it. Those who use it enjoy long ragchews, home-built equipment and a surprising amount of summer DX. This guide explains where the band is allocated, why the rules differ, how signals travel at 70 MHz, what equipment you can use and how to find other stations.

If you live in a country where the band is open, it can be one of the most rewarding experiments in your shack. If you do not, it is still an interesting case study in how spectrum and national regulation shape what hobbyists do.

What the 4 Meter Band Is

The 4-metre band, also called the 70 MHz band, is an amateur radio allocation in the lower part of the very high frequency range. As the overview of the 4-metre band notes, only a few countries inside and outside Europe have allocated it for amateur access, so the choice of commercially manufactured equipment is limited. Most operators on the band are interested in building their own equipment or modifying private mobile radio gear, and communication tends to focus on technical topics, with long rag chews the norm whenever there is local activity.

A Brief History

Before the Second World War, British amateurs had a band at 56 MHz. After the war they were moved to a 5 metre band at 58.5 to 60 MHz, which lasted only until 1949, when it was earmarked for BBC television. After several years of lobbying by the Radio Society of Great Britain, the 4 metre band was allocated to British amateurs in 1956 as a replacement. At first the allocation was only 200 kHz wide, from 70.2 to 70.4 MHz. It was later extended, and it eventually settled at today’s 500 kHz allocation of 70.0 to 70.5 MHz.

During the International Geophysical Year of 1957 and 1958, several other countries received frequencies between 70 and 72.8 MHz for amateur use. The modern growth of the band came later, as stations in Eastern Europe moved away from the old broadcast band and commercial users migrated to higher frequencies, freeing space. More European and African countries have authorised the band in recent years.

Allocations and Why They Differ

There is no worldwide allocation at 70 MHz, so national rules decide everything. The United Kingdom and a few other places were the traditional users, and an increasing number of countries in Europe and Africa have authorised it. Within Europe, CEPT recognises the use through a footnote that was updated in July 2015 to say that CEPT administrations may authorise all or parts of the band 69.9 to 70.5 MHz to the amateur service on a secondary basis. In practice, that means 70.0 to 70.5 MHz in the United Kingdom, and a smaller slice inside that window in most other countries.

Power limits are usually lower than on other amateur bands, to reduce the chance of interference to other services, especially in neighbouring countries. Because the details vary so much, the Four Metres Website, 70mhz.org, maintains a table of national and regional allocations. Always check it, and your own regulator, before you transmit.

Propagation at 70 MHz

The 4 meter band shares many characteristics with the adjacent 6 meter band, but it behaves slightly differently because it is higher in frequency. The F2 layer propagation that sometimes appears on 6 meters is not normally seen at 70 MHz at temperate latitudes. The common long-distance mechanisms are these:

• Sporadic E. Clouds of intense ionisation in the E layer are common on the band during the summer season, and allow Europe-wide contacts. Our guide to sporadic E and gray line propagation explains how it works, and the same ideas apply to 70 MHz openings.
• Tropospheric propagation. It is marginally more successful than on 6 meters. For the weather patterns that cause it, read our article on tropospheric ducting.
• Meteor scatter. Reflections from meteor trails are generally highly effective at these frequencies. See our MSK144 meteor scatter guide for the modes and procedures.
• Aurora. Propagation via the aurora is generally effective, mostly for stations at higher latitudes.
• Transequatorial propagation. A first 70 MHz transequatorial contact was made in March 2011 between stations in Greece and South Africa.

During the European summer the band is frequently open for DX across the continent, with long-distance voice and digital activity concentrated in the lower part of the band. Our 6 meter band guide shows the same seasonal patterns and the tools used to catch them.

Interference: Broadcasting and Neighbours

Although much of the old broadcast use has gone, the band is still used for wide-bandwidth, high-power FM broadcasting in the OIRT FM band in a declining number of Eastern European countries. Where those transmitters operate, they can cause significant interference to both local and DX operation. Another reason to expect lower power limits is the proximity of other services, including television channels, in some countries. Listen before you transmit, and be ready to move within your allocation.

Equipment: How to Get on 4 Meters

Access to the band remains a challenge because few manufacturers build dedicated 4 metre transceivers. Operators generally choose among these options:

1. Modern multiband transceivers. Some current HF and VHF all-mode radios include 70 MHz coverage. The band overview mentions several well-known models that natively support all-mode operation on 4 meters, although output on that band is commonly limited. Check the manual of your own radio to see whether it includes the band and with what power.
2. Converted private mobile radio. Used commercial radios, retuned and sometimes modified, are in widespread use. Typical examples named in the band overview are the Philips FM1000 and the Ascom SE550.
3. Low-power FM units. Some commercial low-power FM equipment is available. These are relatively simple and generally suitable for contacts up to around 50 kilometres with simple antennas.
4. Transverters. A transverter converts another band, usually 28 MHz or 144 MHz, to and from 70 MHz, and lets you use an existing all-mode radio. It adds complexity, but gives SSB and CW capability.
5. Home construction. The band attracts builders, and kits and circuits are published in amateur literature.

Whichever route you take, check that the radio’s power and frequency settings comply with your national allocation. A converted radio may need its output reduced.

Antennas for 70 MHz

An advantage of the band is that its antennas are compact. Both horizontal and vertical antennas designed for 70 MHz are small compared with those for lower frequencies, which suits operators with limited space who want to try DX without large multi-element arrays. A half-wave dipole is only around two metres long, and a small Yagi is a manageable project.

• Vertical antennas are convenient for FM and local nets, particularly where FM is the common mode.
• Horizontal beams are the standard for weak-signal and DX work, since SSB and CW stations conventionally use horizontal polarisation.
• Quarter-wave ground plane or J-pole designs are easy to build. The design principles are covered in our guide to 2 meter antennas, and the same approaches scale to 70 MHz.

Always measure a home-built antenna with an analyzer before you connect a transmitter, and trim it to resonance inside your allocation.

Calling Frequencies and Modes

Because the band is so lightly used, a handful of calling frequencies concentrate activity. According to the band overview, DX voice traffic in SSB is found around the SSB calling frequency of 70.2 MHz, while AM and FM contacts tend to start at the 70.26 MHz AM and FM centre of activity. Exact calling frequencies vary by country and club, so treat these as starting points and check the national band plan and 70mhz.org.

The band supports a mix of modes:

• AM and FM for local contacts and nets, particularly in the United Kingdom and Ireland.
• SSB and CW for DX and weak-signal work.
• Digital modes when conditions are poor or power is modest. Modes such as PSK31, Thor and Olivia can be decoded at relatively low signal-to-noise ratios, and more resilient modes such as FT8 can produce reliable signal reports over distances of several hundred to several thousand kilometres, depending on conditions.

In countries where 70 MHz is not allocated, operators often use cross-band working with 6 meters or 10 meters to arrange contacts with stations on 4 meters elsewhere.

A Starter Plan for 70 MHz

If your country allows the band and you want to try it, a simple plan will save time and money.

1. Confirm the rules. Look up your national allocation, power limit, permitted modes and any licence class restrictions, then write them down.
2. Listen first. If you already own a receiver or an SDR that covers 70 MHz, listen on the calling frequencies in the evenings and on summer days. Hearing activity tells you whether the band is worth the investment where you live.
3. Find a local contact. A nearby station on the band will give you a signal report, tell you which modes are popular locally and may lend equipment.
4. Start simple. A small vertical or a dipole and a low-power radio are enough for local contacts. Add a horizontal beam later if you want DX.
5. Use beacons. Where beacons exist on the band, they give a quick check on whether a path is open, and they help you calibrate your station.
6. Build or buy for the long term. If you enjoy the band, a transverter or a multimode radio will give you SSB and CW without the limits of an FM-only unit.

Because the community is small, operators tend to be helpful. Post your results and ask questions, and you will often be pointed toward the people who are active in your area.

Common Mistakes

• Transmitting without checking the allocation. It is not an international band, so confirm it is legal for you.
• Using too much power. Limits are often lower than on 2 meters or 6 meters.
• Using a converted radio unchecked. Verify frequency, output and spurious emissions before going on the air.
• Calling in the wrong part of the band. Respect the calling frequencies and the local band plan.
• Expecting the activity of 2 meters. The band is quiet. Schedule contacts and listen for beacons.

The Bottom Line

The 4 meter band is a niche, and that is both its challenge and its appeal. It offers compact antennas, summer sporadic E openings, effective meteor scatter and a friendly technical community, but it demands that you check your national rules and put in some effort to find equipment. If your country allows 70 MHz, start with the allocation table on the Four Metres Website, choose a radio or transverter that complies with your limits and listen on the calling frequencies in summer. Even a modest station can make surprising contacts, and the quiet band rewards patience.

Frequently Asked Questions

What frequency is the 4 meter band?

It is centred on 70 MHz. In the United Kingdom the allocation is 70.0 to 70.5 MHz, and in other countries it is usually a smaller slice of the range around 69.9 to 70.5 MHz.

Can I use the 4 meter band in my country?

That depends on your national regulator. Only a limited number of countries have authorised it. Check the allocation table on the Four Metres Website and confirm with your regulator.

Why are power limits lower on 4 meters?

To reduce the chance of interfering with other services, especially in neighbouring countries. In most countries the maximum power on the band is lower than on other allocations.

What radios work on 4 meters?

Some modern all-mode transceivers include 70 MHz, and converted private mobile radio equipment is widely used. Transverters and home-built gear are also common. Check your radio’s manual.

Is the 4 meter band good for DX?

In summer, sporadic E can open the band across Europe, and meteor scatter works well all year. Transequatorial contacts have also been made. It is quieter than 6 meters, so DX requires patience.

What is the SSB calling frequency on 4 meters?

The band overview gives 70.2 MHz as the SSB calling frequency for DX, with 70.26 MHz as the AM and FM centre of activity. Confirm against your national band plan.