23 cm Band Guide: 1296 MHz Gear, Modes and Propagation

Beyond the familiar 2 metre and 70 centimetre bands, the next step up in frequency opens a different kind of amateur radio. The 23 cm band, also known as 1296 MHz or the 1.2 GHz band, sits at the boundary between UHF and the microwaves. Antennas become small enough to hold in one hand, gain is cheap and the band is much quieter than the crowded lower bands. At the same time, cable loss rises, the equipment is less common and the signal behaves more like light than like HF. This guide explains where the band is, how it is shared, what you need to get on the air, which modes people use and how signals travel, so you can decide whether to try it.

Where the 23 cm Band Sits

As the 23-centimeter band article summarizes, it is a portion of the UHF spectrum allocated internationally to amateur radio and amateur satellite use on a secondary basis. The amateur band runs from 1240 MHz to 1300 MHz. The allocation is the same in all three ITU regions. The band for amateur satellite use is between 1260 MHz and 1270 MHz, and satellite use is limited to uplinks, on a non-interference basis to other users. In the United States the table of amateur bands in 47 CFR 97.301 shows the same 1240 to 1300 MHz range for all three regions. Some countries allow more. The United Kingdom allocation extends to 1325 MHz, for example, and Ireland extends to 1304 MHz, so local rules always apply.

The wavelength is about 23 centimetres, which is where the name comes from. At 1296 MHz the wavelength in free space is about 23.1 cm, so a half-wave dipole is only about 11.6 cm and a quarter-wave element is under 6 cm. That is why a modest antenna can have a good deal of gain in a compact package.

A Secondary Allocation Shared with Radar and Navigation

The word secondary matters. Amateurs may use the band, but they must not interfere with primary users, and they cannot claim protection from them. The primary allocation to radiolocation has the highest priority, which means that radar systems share the band with us. Satellite navigation systems also use this part of the spectrum. The article notes that radionavigation satellite services such as Glonass and Galileo operate in this range, and that the World Radiocommunication Conference of 2023 considered further constraints on the band to protect them. The ITU published guidance for amateur and amateur satellite use in November 2023, as recommendation M.2164.

The practical result is that conditions on 23 cm are not the same everywhere. In some areas you will hear pulses from radar, and in some regions the IARU has designated a segment from 1240.000 to 1240.750 MHz as an alternative centre of activity for narrowband modes and beacons, to reduce conflicts. If you plan to operate seriously, read the band plan used in your region and follow it.

Calling Frequencies and Activity

As on other VHF, UHF and microwave bands, weak-signal operators gather around calling frequencies. According to the published band plans, the CW and SSB calling frequency in IARU Region 1 is 1296.2 MHz, and the FM simplex calling frequency is 1297.5 MHz. In Region 2, the CW and SSB calling frequency is 1296.1 MHz, and the FM simplex calling frequency is 1294.5 MHz. In Australia, the FM simplex calling frequency is 1294.0 MHz. Use the calling frequency to find a contact, then move to a clear spot to continue the conversation.

Most modes can be found on the band. Common ones include voice on FM and SSB, CW, data, EME or moonbounce, and amateur television. Activity levels depend on where you live. In some regions, especially in northern and central Europe, there are active repeaters and weak-signal groups. In others, you may be the only station for hundreds of kilometres, and a contact has to be arranged in advance by a sked.

Equipment: Transverters, Radios and Power

Few general-purpose HF transceivers cover 1296 MHz, so the usual route is one of these.

• An all-mode VHF/UHF/SHF transceiver. Several modern all-mode radios include 23 cm in their coverage. That is the simplest option for SSB, CW and FM, and it works well with the digital modes.
• A transverter. A transverter shifts a 2 metre or 70 centimetre radio signal to 1296 MHz, and shifts the received signal back. It allows you to use the modes and the filters of your existing rig, and it is the traditional route for weak-signal work.
• FM handhelds and mobile radios. A few dual- or triple-band FM radios include 23 cm. They suit repeater access and simplex.
• Amplifiers. A power amplifier of tens of watts is common for weak-signal work, and larger solid-state amplifiers are used for EME. Amplifier cost, cooling and feedline loss rise rapidly with frequency, so many operators invest in the antenna before they invest in power.

A low noise preamplifier mounted at the antenna matters more at 1296 MHz than it does lower down, because cable loss ahead of the receiver adds directly to noise. The preamplifier must be protected during transmission, so a mast-mounted unit needs a relay or a sequencer that disconnects it from the antenna before the transmitter keys up. Skipping that step is a quick way to destroy a very expensive low-noise device. Read the manual of the preamplifier, check its maximum input power and its bypass behaviour when power is removed, and test the sequence at low power before you trust it.

Receiver noise figure is only part of the picture. At these frequencies the antenna also sees the warm ground and the sky, so a very low noise receiver mostly pays off when the antenna points at cold sky, such as in EME work. For terrestrial paths, the benefit of a preamplifier is real but smaller, and reducing feedline loss often gives a larger improvement than buying a better receiver.

The Feedline Problem

Cable loss increases with frequency, and at 1.3 GHz it becomes the biggest limit on station performance. Cable that is perfectly adequate for HF or even 2 metres can lose a large fraction of the power on 23 cm over a run of a few tens of metres. The practical rules are simple.

• Keep the run short. Put the transverter or the amplifier close to the antenna if you can.
• Use low-loss cable. Large-diameter low-loss coax or semi-rigid hardline is common for longer runs. The comparison in our article on RG-58, RG-8X and LMR-400 shows how quickly small-diameter cable falls behind as the frequency rises.
• Choose connectors carefully. N-type connectors are the common choice at this frequency. The common PL-259 is not designed for UHF and above, and a poor connection becomes a major loss.
• Waterproof every joint. Water in a connector is far more harmful at microwave frequencies.

Antennas for 1296 MHz

Because the wavelength is small, antennas with high gain are physically small. Popular choices are Yagis with many elements, loop Yagis, quad-style antennas, collinear arrays and parabolic dishes with a suitable feed. A dish of modest size offers high gain for EME work, but it needs accurate pointing. Antennas with a high gain have a narrow beam, so the beamwidth is a matter of degrees. A rotator that can set the elevation as well as the azimuth is necessary for tropospheric work in many places and essential for satellites and EME.

Polarization is a convention. For weak-signal work on SSB, CW and digital modes, horizontal polarization is the usual choice, so a cross-polarized station will lose signal. FM repeaters and simplex users often use vertical polarization. Check what your local community does before you buy or mount an antenna.

An important point about gain is that antenna gain compensates for feedline loss only if the loss ahead of the antenna is small. A very high gain antenna on the far end of a lossy cable is not a good investment. Many 23 cm stations place a small transverter or a preamplifier at the mast to avoid this.

Propagation on 1296 MHz

At 23 cm the signal propagates mostly in line of sight, which is a little beyond the visual horizon because of the refraction in the atmosphere. Several mechanisms extend that range.

• Tropospheric ducting. A temperature inversion can trap the signal and carry it for hundreds of kilometres. Our guide to tropospheric ducting explains how the openings appear and how to watch for them.
• Aircraft scatter. A passing aircraft can reflect the signal for a short time. The signals appear as brief, strong pulses and rise and fall with the movement.
• Rain scatter. At microwave frequencies, raindrops can scatter the signal into areas beyond line of sight.
• Moon reflection. The moon is a very large, very weak reflector. EME at 1296 MHz is a popular microwave activity, and the beginner’s guide to EME moonbounce and Q65 covers the modes and the principles. It needs a good antenna, a low-noise receiver and patience.
• Satellites. Some amateur satellites use the 1260 to 1270 MHz segment for uplinks, so a 23 cm transmit capability opens another way into satellite operating.

Unlike HF, there is no ionospheric propagation at these frequencies in everyday conditions. The advantage is stability: a path that works today is likely to work tomorrow, except in the case of weather effects.

Comparison with Lower Bands

If you are used to the lower VHF and UHF bands, our guide to VHF and UHF simplex and repeater operating is a good reference for the habits you can bring with you.

Getting Started: A Simple Path

1. Check your licence and local band plan. Confirm that the whole 1240 to 1300 MHz range is available to you, and read the national and IARU regional guidance.
2. Find out who is active. Ask your local club or look for beacons and repeaters. Your best first contact is likely to be a local station, not an exotic path.
3. Choose the radio. An all-mode transceiver is the easiest. A transverter is the more flexible and affordable way to get weak-signal performance.
4. Plan the antenna and feedline together. Decide the height and the distance to the radio, then choose a cable with an acceptable loss. A short run is worth more than a high-gain antenna.
5. Add a preamplifier if the run is long. It will improve your receive performance considerably.
6. Arrange a sked. Agree a time and a frequency with a friend and try CW or SSB. Hearing your first signal on a new band is one of the best experiences in the hobby.

Take RF exposure seriously at microwave frequencies. High gain antennas and amplifiers concentrate the power into a narrow beam, and the safe distances are larger than most people expect. The article on RF exposure safety explains how to evaluate your station.

The Bottom Line

The 23 cm band offers small antennas, quiet channels and a variety of modes, from FM and SSB to EME and television. It also demands care with feedline, an understanding of its secondary status and some patience about finding other stations. Start with the allocation and band plan, pick a transceiver or a transverter, keep the cable short, add a preamplifier and take advantage of the local activity. A few contacts will show you how different the band feels from HF, and how much you can learn by exploring the edge of the microwave spectrum.

Frequently Asked Questions

What frequencies does the 23 cm band cover?

The amateur allocation is 1240 to 1300 MHz. Some countries, such as the United Kingdom, allow a wider range, so always check your own licence conditions.

What are the calling frequencies on 23 cm?

In IARU Region 1 the CW and SSB calling frequency is 1296.2 MHz and FM simplex is 1297.5 MHz. In Region 2 they are 1296.1 MHz and 1294.5 MHz respectively.

Is the 23 cm band a primary allocation?

No. Amateur use is secondary. Radiolocation and radionavigation satellite services have priority, so amateurs must avoid interfering with them and cannot claim protection.

Can I use ordinary coax on 1296 MHz?

Only for very short runs. Cable loss is high at this frequency, so use low-loss cable or hardline, keep the run short and use N-type connectors.

Do I need a transverter?

Not if you own an all-mode radio that includes 23 cm. Otherwise a transverter lets you use a 2 metre or 70 centimetre rig on 1296 MHz.

Which polarization should I use?

For weak-signal SSB, CW and digital work the usual choice is horizontal. FM repeaters and simplex operators often use vertical. Follow the practice in your area.