> For the complete documentation index, see [llms.txt](https://docs.holybro.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.holybro.com/radio/sik-telemetry-radio-v3/rf-transmission-power-setting-for-1w-variants.md).
# RF Transmission Power Setting For 1W Variants
{% hint style="info" %}
Many countries have different legal RF power ratings. Be sure to operate within the legal limits.
Holybro SiK 1W Telemetry Radio default RF power is set to 21 dBm. Change the Tx Power based on your needs and the regulation limits.
{% endhint %}
Under the Tx Power drop-down menu, there are 21 power levels. But for SIK firmware, only 1, 2, 5, 8, 11, 14, 17, and 20 are valid. If you select an unsupported power value, the firmware will automatically select the valid power value closest to the selected value. For example, if you select 19, the firmware will automatically switch to 20.
Holybro SiK 1W Telemetry Radio adds a 10dB fixed gain amplifier outside the modulation chip, so the Tx Power + 10dB is the final transmission power. The corresponding relationship of the transmission power is as follows:
MissionPlanner value Actual RF power
1 -> 11dbm (12.5mw)
2 -> 12dbm (15.6mw)
5 -> 15dbm (31.25mw)
8 -> 18dbm (62.5mw)
11 -> 21dbm (125mw)
14 -> 24dbm (250mw)
17 -> 27dbm (500mw)
20 -> 30dbm（1000mw)
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://docs.holybro.com/radio/sik-telemetry-radio-v3/rf-transmission-power-setting-for-1w-variants.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.