How Deck works

Deck talks to your radio through the same USB or CI-V cable Icom's own software uses. Everything runs in the browser: there's nothing to install, and nothing about your radio goes through a server. The radio decides what Deck can do, and some things it simply won't do over the cable. This page lists those, and what Deck does instead.

Getting connected

You need Chrome or Edge on a computer (Windows, macOS, Linux or ChromeOS). Only those browsers can open a serial port (Web Serial). Firefox, Safari and every browser on an iPhone or iPad can show the page but can't reach the radio. In any of them you can still try the demo radio, a pretend handheld that answers like the real one.

On the radio: Menu › Set › Function, set USB Connect to Serialport, USB Serialport Function to CI-V, and CI-V Transceive to ON.
Plug the radio into the computer with a USB cable that carries data, not only charge.
Press Connect radio and pick the radio's port. The status turns green, and the frequency and the model's name appear within a second.
Next time, Deck connects by itself when the page opens or the radio is plugged back in. Disconnect stops that until you connect again.

The ID-51 and ID-31 connect through a CI-V cable on the SP jack instead of USB. Set the same baud rate in Deck's connection settings (the sliders button) as on the radio.

Radios

Deck recognises the model from the address it answers from. A radio that ignores Deck's call to every address is asked at each model's factory address in turn, which can take a few seconds the first time; the address it finds is kept. If you changed the radio's CI-V address, pick the model in connection settings, or press Find address.

Model	Connects through	Status
ID-52A/E PLUS	USB-C	Tested on the radio
ID-52A/E	USB-C	Should work, not yet tested
ID-50A/E	USB-C	Should work, not yet tested
ID-5200A/E (mobile)	USB-C	Should work, not yet tested. Power is Low, Mid or High, and there's no attenuator
ID-51A/E	CI-V cable on the SP jack	Should work, not yet tested
ID-31A/E, ID-31 PLUS	CI-V cable on the SP jack	Should work, not yet tested. One band (70 cm), so no band B or dual watch

Using one of the untested ones? Tell me what works and what doesn't (see sending a log).

What the radio won't do over the cable

Icom's handhelds accept only part of their features over CI-V. These limits come from the radio, not the browser, and no app can get around them. Most were found by asking an ID-52 PLUS directly; the other models are assumed to be the same.

Memory channels

The radio won't read out its memories or switch to one. Deck always works the radio in VFO mode.

Instead Export the memories to a CSV file (from the radio's SD card menu, Icom's cloning software, or CHIRP) and import it in Channels & memories. Picking a channel sets the frequency, mode, repeater shift, tone and D-STAR calls, just like recalling it on the radio. Deck works in VFO, so a repeater's shift and tone stay after you tune away. They show as a red tag at the top of the display (for example DUP− 0.6 · T 88.5), and Simplex, next to it, clears them on band A, B or both.

The band scope

The radio's own scope can't be switched on or off, or read.

Instead Band sweep steps through a range and reads the S-meter at each point. That takes about 0.1 s per point, so a sweep of 2 m takes about 16 seconds.

Only the active band

Tuning and the S-meter reach only the active band, and the radio won't say which band is active.

Instead Deck finds the active band when it connects, so the radio flicks between A and B for a moment. To tune the other band, it makes that band active, tunes it, and switches back.

Audio

The USB cable carries control only, no sound, in either direction.

Instead The decoders listen on the computer's line-in, and sending APRS plays into the radio's mic jack. See audio cables.

Tone scan

There's no command to scan for a station's CTCSS tone or DCS code.

Instead Find tone tries the 50 tones and 104 codes one by one while the station transmits, and sets the one that opens the squelch.

FM broadcast and wide FM

The radio refuses 76–108 MHz over the cable, and WFM can't be set. So broadcast FM and wideband satellites such as the Meteor weather satellites are out of reach.

Airband on band B

On the ID-52 and ID-52 PLUS, band B doesn't receive 108–137 MHz.

Instead Deck keeps airband on band A and greys out B there.

Built-in microphone gain

Only the gain for a mic or cable on the SP jack can be set (steps 1–4), not the built-in mic's.

Doppler on transmit

The transmit frequency can't be shifted on its own while receiving.

Instead Satellites corrects Doppler on receive only. On 2 m FM the shift is under 3.5 kHz, which FM satellites tolerate.

Turning on over USB

When the radio turns off, its USB port disappears, so nothing can reach it to turn it back on.

Instead Turn it on with its own button and Deck reconnects by itself. On a CI-V cable the port stays, so Deck's power button turns it on too.

An APRS modem

The radio has no FM APRS modem of its own.

Instead Deck decodes APRS from the radio's audio, and to send, it makes the packet's audio itself, keys the radio, plays it into the mic input and goes back to receive.

Audio cables

Tuning, levels, band sweep, satellites, D-STAR and channels all work over the one USB cable. These features also need sound:

Feature	Needs
Morse IDs, APRS and SSTV decoding	The radio's speaker or SP output into the computer's line-in, picked under Audio in. Set the radio's volume so it's neither clipped nor lost in noise.
Sending APRS	The computer's audio output into the radio's mic input, picked under Audio to the radio's mic. VOX must be off: Deck checks, and offers to turn it off before sending.
Talking with PTT	Nothing extra: the radio sends its own microphone, or whatever is plugged into its mic jack.

Your data

Settings, saved channels, imported memories, heard station IDs, APRS packets, the D-STAR heard list and DV texts, and SSTV pictures are kept in this browser. Another browser or computer starts empty, and clearing the site's data forgets them.
Your location, from the radio's GPS, this device or typed in, stays in the browser too. It's used for satellite passes and APRS distances.
The only thing Deck asks its server for is satellite orbit data, which it fetches from CelesTrak. The page's fonts come from Google Fonts.
Visits are counted with Vercel Web Analytics and Cloudflare Web Analytics: which pages are opened, from which country and on what kind of device. Neither sets cookies or can tell who you are, and neither sees anything about your radio.

When something doesn't work

Connect radio is greyed out: The browser has no Web Serial. A banner at the top says which browser it is. Open Deck in Chrome or Edge on a computer.
The radio isn't in the port list: Check the radio's menu settings above, and try another USB cable: many are charge-only.
Connected, but no frequency shows: The radio isn't answering. Check CI-V Transceive is on and, on a CI-V cable, that the baud rate matches. If you changed the radio's address, press Find address in connection settings.
A message says the radio refused something: That command isn't accepted by this model, on this frequency, or in the radio's current state. The message names what was refused.
Weak stations have gone quiet: Check for ATT on the display: the attenuator takes 30 dB off on 2 m and 10 dB on 70 cm. Press ATT under the display to turn it off. It's meant for overload near a strong transmitter.
Nobody hears me on a simplex frequency: Check the display for a DUP, T, TSQL or DTCS tag: a repeater channel picked earlier left its shift or tone on the VFO, so the radio transmits off frequency or listens only for that tone. Press Simplex at the top of the display and pick the band, or both, to clear them.
The mode jumps from DV to FM by itself: That's the radio: with DV Auto Detect on, it switches to FM when it hears an FM signal on a DV frequency. Deck notes it in the CI-V log when it happens without a mode change from Deck. Turn DV Auto Detect off on the radio to stay in DV.
APRS shows nothing, or only garbled packets: Almost always the volume: too loud clips, too quiet drowns in noise. The APRS line under the switches says what the decoder hears. If packets come out garbled at the start (the sender's call sign mangled, the rest fine), the squelch or the radio's Power Save is cutting their beginning: turn on Squelch open next to Decode APRS, and Power Save off on the radio. A laptop's built-in mic may also gate the start of each burst; a cable into a line-in or USB sound card avoids it. In connection settings, Debug › Play a test packet checks the audio path.
Anything else: Open connection settings, tick Show CI-V traffic under Debug, repeat the problem, press Copy log, and send it to me, with the radio's model, through the links below.