# MeshCore App: Radio Settings and Position

## Radio Settings

Access via Settings → Radio (or Device → Radio Config depending on app version).

### Preset Selection

The most important radio setting. Always use the preset that matches your local network:

- **USA/Canada (Recommended)** - North American convention (Oct-2025 "narrow"): 910.525 MHz, SF7, BW 62.5 kHz, CR5. Use this unless your local community uses something different.
- **Europe** - 868 MHz band. Use it on EU-region networks; make sure your hardware and antenna support 868 MHz.
- **Custom** - Manual parameter entry. Only use if you know exactly what you're doing and why.

> Do not use Custom preset unless your network coordinator specifically instructs you to. Incorrect custom settings make your node invisible to the rest of the network.

> **Important:** MeshCore firmware boots on the EU default (869.525 MHz) until you set a region, and the device *will* transmit on that default. You must set the correct region/preset for North America before relying on the node.

### TX Power

Transmit power in dBm (valid range 1-22 dBm on SX1262 hardware). Higher power = more range and more power consumption. Under FCC Part 15.247 (902-928 MHz), the maximum conducted output is 30 dBm (1 W). With an antenna of 6 dBi or less this gives 36 dBm (4 W) EIRP. For every dB of antenna gain **above** 6 dBi you must reduce conducted power by the same dB (15.247(b)(4)), so EIRP stays at or below ~36 dBm. Example: a 9 dBi antenna requires reducing TX power to 27 dBm. The 36 dBm EIRP figure is a ceiling, not free headroom - do not assume you can run full 1 W into any high-gain antenna, and note that the fixed point-to-point high-gain exemption does not apply to point-to-multipoint mesh use. The app displays the maximum for your hardware; leave at default unless you have a specific reason to reduce it.

## Position Settings

Access via Settings → Position.

### Enable GPS

If your device has a GPS module, enable it here. GPS provides position for the contact map and enables distance calculation in the contacts list. On fixed infrastructure nodes, GPS is optional if you configure a static position manually.

### Fixed Position

For nodes without GPS, or for fixed repeaters where GPS accuracy is not needed:

1. Enable "Fixed Position"
2. Enter latitude and longitude
3. Tap Save - the node will broadcast this position in its advertisements

Use your actual deployment coordinates, not your home address. The position is broadcast to the network and appears on community maps.

### Position Privacy

If you don't want your exact position broadcast on the public network, disable position reporting, or set an approximate fixed position (e.g. a nearby landmark rather than your exact coordinates) instead of your precise location. Infrastructure operators typically share full position; personal nodes may prefer to share only an approximate location or none at all.

## Advertisement Settings

MeshCore advertisements use one of two modes rather than a generic numeric hop limit: **flood** (rebroadcast by repeaters, so it propagates network-wide) or **zero-hop** (heard only by nodes in direct range, local only). The CLI equivalents are `advert` (flood) and `advert.zerohop`.

- **Advertisement Interval** - How often your node broadcasts its existence. There are two separate intervals: the flood advert interval is set in hours (3-168, default 12 hours), and the zero-hop advert interval is set in minutes (60-240). The default 12-hour flood interval is appropriate for stable deployments. Reduce the interval during initial setup to confirm discovery.
- **Advertisement Mode** - Choose flood for network-wide visibility (community repeaters) or zero-hop for local-only announcements.
- **Node Name** - Your node's display name. Use a consistent format with your community's naming convention.