After replacing a VTX: check Factory and power values in the VTX Table

01 / Identify the control method

Betaflight explains that analog VTX control over SmartAudio or Tramp requires an appropriate VTX Table. MSP VTX devices can announce channel, band and power information, so the same table workflow is not required.

This guide focuses on analog SmartAudio/Tramp devices. It is not a universal DJI or Walksnail setup procedure. Record the VTX, flight controller and software versions before consulting current documentation.

02 / A shared brand does not establish a shared table

Editorial advice: save the existing configuration and VTX JSON first. Confirm the replacement’s exact model, hardware revision, protocol and table with its manufacturer. Do not carry over an old file merely because the brand, housing or power label looks familiar.

A photograph helps identify markings. The Alpha 16 marking below does not establish a particular SmartAudio version or replace a manufacturer table.

Real AKK Alpha 16 photograph showing its model marking — Source: user-owned AKK A16 photo. Use it to identify markings, not to infer the control protocol or power table.

03 / Factory changes how the setting is sent

The official VTX Tab documentation says that Factory sends band and channel numbers; the transmitter uses its built-in frequency table. The entered frequencies then serve displays such as the OSD. Without Factory, the flight controller sends the entered frequency.

Check the Factory setting against device requirements even after copying frequency numbers. Direct frequency entry also requires transmitter support; it is not a universal repair option.

04 / Power Value and Label have different jobs

Value is the manufacturer-defined power-control value; Label is the displayed name. Changing a label to “1W” does not establish a measured 1W RF output.

Editorial advice: keep the manufacturer’s Value-to-Label mapping. Do not treat every device’s Value as milliwatts. A selected level, reported status and measured RF power are different information. No power measurement was performed for this guide.

05 / Verify communication and saved settings

Editorial checklist: back up first; match the manufacturer JSON to the model and revision; inspect frequencies, Factory and Value/Label; save to the flight controller and inspect again; check Device ready, VTX Type and Current Values. Device ready establishes FC-to-VTX communication only.

Remove propellers for bench checks. Follow the device manual for a matching antenna, rated supply and cooling. The photograph locates a cable socket, not its pinout. If communication fails, check the actual control wire and Ports settings before changing power values at random.

Real AKK Alpha 16 photograph showing its cable socket and fan wires — Source: user-owned AKK A16 photo. Locates the cable socket; consult revision-specific documentation for pins and protocol.

Sources & verification date

Official sources checked on 12 October 2026. A configuration guide, not firmware news or an RF test. The AKK Alpha 16 photos do not provide its dedicated table, pinout or measured output. The video was published on 27 April 2022 and covers Betaflight 4.3; current interfaces may differ.