Divimath, Inc. (HDZero) Whoop Lite VTX

The HDZero Whoop Lite VTX from Divimath (HDZero) is an ultralight digital FPV video transmitter for tiny whoops on 1S to 3S, selectable at 25 or 200 mW. It weighs 4.5 g without shielding and measures 32.5 x 32.5 mm. Dealers list the module as discontinued and name the HDZero Whoop V2 as its successor; the manufacturer's page still lists it in the category.

The picture is 720p at 60 fps. The latency of 14.1 ms is the general HDZero figure from glass to glass, that is from camera to display, a best case for the system and not a measurement on this module. The transmitter offers 40 channels. Power consumption is 5 W according to the manufacturer's page; in a transmitter that weighs a few grams and sits in a small drone without cooling, that is a heat question; when stationary it heats up quickly.

In the EU, 25 mW EIRP is allowed in the 5.8 GHz band without a licence; the 200 mW step can be used there only with the appropriate permit. For tiny whoops flown without a licence the 25 mW step is therefore the relevant one in the EU. Equipment may be operated only in the approved frequency ranges and power levels. Tiny whoops with propeller guards are often flown indoors in a hall, where low power is enough anyway.

When choosing, the status counts: anyone planning a replacement or a new build should look at the successor, because the module is no longer consistently supplied by dealers. The goggles must speak HDZero. The module should not run for long when stationary, since it gets hot without airflow; the solder joints on the tiny device and the antenna are the wear points in crashes.