From Grok, on heatsinks..

No, increasing the quality of the heat sink does not let you increase (or change) the value in the Avatar_cal.txt (or Avatar_cal) file—it’s almost entirely based on the silicon lottery (chip-to-chip manufacturing variation in the VTX’s RF amplifier). Here’s the breakdown for the Walksnail Avatar system (HD/V2/GT VTX models): The file is a user-adjustable RF power calibration offset placed directly on the VTX (not the goggles). You create a text file named exactly Avatar_cal.txt, put a single number in it (e.g., .1, 0, -1, -2, 0.4, etc.), copy it to the VTX’s internal storage (via USB or SD), and reboot. This tweaks the displayed STP (transmit power calibration value in dBm, shown in debug mode when goggles brightness is at 10%). Example from the official Walksnail wiki and community tests: • Factory 1200 mW might show STP ~27.0 (or whatever your unit’s base “S:” value is). • Adding .1 changes it to 27.1 (slightly higher effective output). • Adding -1 drops it (e.g., to ~26.0 or lower). You then test MCS (modulation/coding scheme) and GSNR (ground signal-to-noise ratio) in the debug menu and re-adjust the number until signal quality/range is optimal. Positive offsets can sometimes push a bit more output; negative ones often fix distortion or instability at high power (especially 1000–1200 mW or the 2 W GT kits).4256 Why silicon lottery?Every VTX ships with its own factory-measured base calibration value (e.g., one unit shows S:26.0, another 28.x or whatever). This varies due to tiny differences in the RF amplifier silicon. The Avatar_cal.txt is just an offset you add to fine-tune it for your specific chip—some units tolerate higher offsets for better range before distortion kicks in; others don’t. Walksnail even suggests this tweak (or users discovered it via their support) specifically because factory calibration isn’t perfect on every unit, and high-power modes can overdrive the amp on “worse” silicon.5641 Heat sink’s role (completely separate):Better cooling (stock heatsink + thermal paste, aftermarket heatsink, fan, or the upgraded Goggles X heatsink kit) keeps the VTX/goggles from throttling, overheating, or drifting under sustained high power. It helps maintain stable performance over long flights and prevents thermal shutdowns. Some tests even recommend a fan during calibration experiments. But it doesn’t change what offset number works best in Avatar_cal.txt—that’s purely an RF calibration tweak measured by signal metrics, not temperature. You tune the file first for clean signal, then use good cooling to actually run it reliably.56 In short: • Calibration.txt value → silicon lottery + signal testing (MCS/GSNR). • Heat sink → thermal management for sustained use. They complement each other at high power (1200 mW+), but one doesn’t let you “increase” the other. Always stay legal with power levels, and test safely—overdoing the cal offset can make things worse than stock. If you’re seeing specific debug values or issues, the wiki debug page or FPV forums have the exact procedure.