A DMR codeplug is the complete configuration file (or “programming file”) that you load into your Digital Mobile Radio (DMR) to tell it exactly how to operate. It contains all the settings, channels, talkgroups, and other parameters needed for the radio to communicate on DMR networks (like BrandMeister, DMR-MARC, or local repeaters) as well as analog FM.
Think of it like the operating system and apps for your radio: without a codeplug, the radio is just hardware; with a good one, it’s fully programmed and ready to use worldwide.
- File format: Usually a proprietary binary file (e.g., .dat, .img, .rpt, .csv exports) specific to the radio model and CPS software.
- Size: Can range from a few KB (simple) to several MB (thousands of channels and contacts).
- Compatibility: Codeplugs are radio-specific in stock firmware (e.g., Anytone codeplug won’t work on a GD-77). However, OpenGD77 firmware makes codeplugs more portable across supported radios (e.g., GD-77, RD-5R, DM-1801).
Main Components of a DMR Codeplug
A well-structured codeplug has these core building blocks (in roughly the order you build them in the CPS):
- Radio Settings / General Configuration
- Your DMR ID (unique 7-digit number from radioid.net).
- Callsign (for display).
- Radio name / intro screen.
- Power levels, squelch, backlight, language, time zone, GPS (if supported), hotkeys, buttons, scan lists, etc.
- Network settings (e.g., BrandMeister server address for hotspots).
- Digital Contacts (the foundation)
- List of all possible destinations: talkgroups (Group Call), individual users (Private Call), or All Call.
- Each entry: Name, number (TG or ID), call type.
- Thousands possible (e.g., worldwide TGs like 91, local ones like 3116, private IDs of friends).
- In OpenGD77: Often imported from CSV files (e.g., full BrandMeister TG list).
- TG Lists (Talkgroup Lists) – OpenGD77 feature (not in stock firmware)
- Groups of contacts (talkgroups) assigned to a channel.
- Allows one channel to access multiple talkgroups (up to 32 per list).
- You cycle through TGs on the radio with arrows.
- Controls receive filtering: Radio only plays audio from TGs in the list (plus current one).
- Examples: “BM Worldwide”, “Local Static”, “TAC310”, “Simplex”.
- Channels
- The actual operating slots: define frequency, timeslot (TS1/TS2), color code, power, bandwidth, etc.
- Digital channels: Assign a TG List (for multi-TG) or single Contact (fixed TG/private).
- Analog channels: Frequency + CTCSS/DCS + FM settings.
- Simplex (direct) or repeater channels.
- Best practice: One channel per frequency/repeater — use TG Lists to handle multiple TGs.
- Zones
- Folders/groups of channels for easy navigation.
- Up to 80 channels per Zone (limit varies).
- Channels can appear in multiple Zones.
- On radio: Select Zone first → scroll only those channels.
- Examples: “Hotspot”, “Local Repeaters”, “Worldwide TGs”, “Analog VHF”.
- Scan Lists (optional)
- Groups of channels to scan sequentially.
- Can scan by Zone or custom lists.
- Other Elements
- RX Group Lists — Advanced receive filtering (similar to TG Lists but for receive only).
- Encryption (if supported, rare in amateur use).
- Boot screen, alert tones, VOX, etc.
How a Codeplug Works (Build Order)
| Step | Component | Purpose / Why First? |
|---|---|---|
| 1 | Radio Settings + DMR ID | Personalize the radio |
| 2 | Digital Contacts | Define all possible TGs and private IDs |
| 3 | TG Lists | Group contacts for multi-TG channels |
| 4 | Channels | Create operating configs (link to TG Lists/Contacts) |
| 5 | Zones | Organize channels into user-friendly groups |
| 6 | Scan Lists + Extras | Add scanning and tweaks |
OpenGD77 vs. Stock Firmware Codeplugs
| Feature | Stock Firmware (e.g., Radioddity, TYT) | OpenGD77 Firmware |
|---|---|---|
| TG Lists | No (one TG per channel) | Yes (multi-TG channels) |
| Codeplug portability | Radio-specific | Works across many models |
| Contacts limit | Often limited (e.g., 10k) | Much higher (100k+) |
| CPS software | Manufacturer CPS (clunky) | OpenGD77 CPS (modern, CSV import) |
| Complexity | Requires many duplicate channels | Fewer channels needed |
| Best for | Simple setups | Advanced amateur use |
Best Practices for Amateur Radio Codeplugs
- Start small — Build for your local repeater/hotspot first, then expand.
- Name everything clearly — e.g., “KD2LNB TS2 BM Public” instead of “Channel 123”.
- Use TG Lists — Dramatically reduces channel count (OpenGD77).
- Organize Zones logically — By location (e.g., “NYC Repeaters”), type (“Hotspot”), or use (“Worldwide”).
- Duplicate useful channels — Put popular ones (e.g., Parrot, Worldwide 91) in multiple Zones.
- Backup often — Save versions (e.g., “2025-NYC-v3”).
- Import contacts — Use BrandMeister CSV exports for full TG lists.
- Test thoroughly — Write to radio, test transmit/receive on known TGs.
- Share wisely — Codeplugs contain your DMR ID — sanitize before sharing.
In short: A DMR codeplug is your personalized blueprint for turning a DMR radio into a powerful, global communication tool. With OpenGD77, it’s much more efficient and flexible than stock firmware — allowing fewer channels, more talkgroups, and easier organization. A well-made codeplug makes DMR feel seamless, whether you’re chatting locally or worldwide!