Setting antenna gain for external antenna

Gateways MultiTech Gateways
1

I’ve successfully configured a Multitech Conduit for TTN. I want to add an external antenna and need to specify the gain (8dbi). Since I used a third party packet forwarder script, it looks like I need to manually specify the gain in one of these files:

/var/config/lora/local_conf.json
or /var/config/multitech_overrides.json

It’s a bit confusing since this installation seems to be mostly using multitech_overrides.json to set device-specific attributes but there are also some device-specific items in local_conf.json.

I’ve tried both ways and it doesn’t break after restarting the LoRa service, but how do I know it’s actually working (ie, maintaining allowed Tx power given the 8dbi gain antenna)?

    "SX1301_conf": {
            "clksrc": 0,
            "clksrc_desc": "radio_0 provides clock to concentrator",
            "antenna_gain": 8,
            "antenna_gain_desc": "antenna gain, in dBi"
    },
2

Using that that value will actually result in issues in some cases, the advice is not to change it.

If you feel you really need to you should use local_conf.json.

3

Thanks for the reply. When you say “Using that value will actually result in issues…” are you referring to setting “antenna_gain”: 8 or are referring to editing multitech_overrides.json in general?

Also, however one configures the gain, is there a way to verify it’s working properly?

4

I am referring to setting the antenna gain.

There is no way to check if the setting has the desired effect apart from using measuring equipment to check the output level of the gateway.

Make sure you are running at least 3.0.21-r1 (opkg should list this version) of the software if you decide to use the setting. Older version will drop downlink packets if the setting is used.