LPD and PMR frequencies: full channel and CTCSS table

If you are holding a licence-free radio bought from an electronics store or a marketplace, it almost certainly works in the LPD or PMR bands. These are two sets of frequencies on which, in most countries, low-power handheld stations are allowed to transmit without any permits or a callsign — provided you respect the power limit and a few other conditions. Below is a practical reference: full channel tables, a breakdown of CTCSS/DCS subtones and a careful discussion of legal status.

What LPD and PMR are

LPD (Low Power Device) is a band around 433 MHz with 25 kHz spacing and 69 channels. PMR446 (Private Mobile Radio) is a band around 446 MHz with 8 (under later rules, 16) channels. The core idea behind both standards is the same: to allow simple radio communication straight out of the box, with no licensing, by limiting the radiated power so that the devices do not interfere with other services and work over a range of a few hundred metres to a few kilometres in the open.

It is important to understand that the LPD band partly overlaps with the amateur 70-centimetre band (430–440 MHz). This means that licensed radio amateurs legally operate on the same frequencies with far more power — and, formally, priority belongs to the licensed services. PMR446 is allocated separately, specifically for licence-free use.

LPD channel table (433 MHz)

The LPD grid is built trivially: the first channel is 433.075 MHz, and each subsequent one is shifted 25 kHz higher. The formula for the frequency of channel N:

F(N) = 433.075 + (N − 1) × 0.025 MHz

So channel 1 = 433.075, and the last channel, 69 = 434.775 MHz. A few reference rows to check your setup:

You do not need to memorise the full 69-row grid — any frequency between 433.075 and 434.775 MHz that is a multiple of 25 kHz is simply the next LPD channel. Channel numbering on different radios is sometimes offset, but the frequency grid itself is identical.

PMR446 channel table (446 MHz)

The classic PMR446 is 8 channels with 12.5 kHz spacing, from 446.00625 to 446.09375 MHz. The band was later extended to 446.19375 MHz (channels 9–16), but the base 8 are supported by virtually every radio:

The PMR band is usually "cleaner" and more predictable than LPD: it does not overlap with the amateur 70-cm band, so there is less interference from powerful licensed stations. For everyday use (a construction site, hunting, keeping the family together in a shopping centre, a route in the mountains) PMR446 is generally the better choice.

What CTCSS and DCS are

When several groups of people share one frequency, a subtone mechanism helps. CTCSS (Continuous Tone-Coded Squelch System) is a continuous low-frequency tone (roughly 67–250 Hz) transmitted together with speech below the audible threshold. The radio opens the speaker only when it receives a signal carrying "your" tone. DCS (Digital-Coded Squelch) is the same thing, but a digital code is used instead of an analogue tone.

On radios this is often called the "privacy code", "subchannel" or "CTC/DCS". In the menu you select, for example, channel 3 and subtone 12 — the other party must set exactly the same values, otherwise they will not hear you even standing right next to you.

Legal status

Using the LPD and PMR bands without any permits is possible thanks to spectrum-regulator rulings that allocate these bands to low-power devices for civilian use. Under the rulings currently in force, LPD typically carries a limit on the order of 10 mW effective radiated power, and PMR446 on the order of 0.5 W. It is precisely respecting the power limit (and operating with the standard non-removable antenna, without repeaters) that keeps the use licence-free.

Let us emphasise: the exact wording, power limits, the list of permitted bands and the conditions (for example, a ban on external antennas or relaying) are set by specific regulator rulings and are revised over time. Do not rely on figures from old forums and do not treat the values given here as final — before buying and operating, check against the current ruling. There is a separate, in-depth discussion in our article on frequencies and the law.

• Exceeding the power limit (amplifiers, powerful "Chinese" radios cranked to the maximum) takes you out of the licence-free zone.
• External antennas and repeaters on these bands are generally not permitted for licence-free operation.
• Multi-band radios (which can work in both the amateur and the service bands) do not by themselves make communication illegal — but they place on you the responsibility not to stray beyond the permitted frequencies and power.

How this relates to the amateur bands and DMR

LPD and PMR are the "ground floor": zero bureaucracy, zero training, but also minimal range and features. The next step is amateur radio: it requires an exam, a callsign and a licence, but in return you get more power, repeaters, antennas and digital modes. If you are still choosing your gear, take a look at our guide to your first radio.

The digital standard DMR stands apart. Unlike analogue PMR with its subtones, DMR splits the channel into time slots and uses digital voice coding. The DMR-world equivalent of CTCSS is the Color Code: a digital "subtone" that separates your repeater/network from neighbouring ones on the same frequency. If you want to grasp the logic of digital from scratch, start with our article DMR from scratch. DMR delivers what a licence-free analogue radio fundamentally cannot: clean audio at the edge of range, text messages, identification by a unique ID, and access to global networks through internet gateways.

Summary

LPD (433.075–434.775 MHz, 69 channels, 25 kHz spacing) and PMR446 (446.00625–446.09375 MHz in the base 8 channels) are a legal way to start using a radio today, with no callsign and no fees. CTCSS and DCS will help you share the airwaves with neighbours, but they will not hide your conversation from the curious. And when you want real range, digital quality and communication over the internet — the path runs through amateur radio and digital standards like DMR. Just remember the power limit and check against the current regulator ruling.