UPDATE: Postponed two months due to excessive shipping time + travel scheduled for June/July.
If all goes according to plan and my questions receive the answers I'm hoping for, I'll be placing an order Monday for the ingredients that will result in a balloon-supported WSPR transmitter.
The heart of the project will be the WSPR-TX Pico Transmitter from ZachTech. Finishing up the recipe will be an SBS-12 or -13 balloon and local procurement of either helium or hydrogen.
The gas used is not as simple as it seems - there are different dilution levels of each gas, depending on its intended purpose and where it is sourced.
So there is some learning to be done - but the transmitter is decided.
I had been waiting on G0UPL's previously-announced U3B - a stripped down, lightened version of his U3S. But, after three years, it's time to look elsewhere, thus the Pico.
Although light, these weigh significantly more than the U3 variants flown on balloons by a few so I'm certainly not hoping for anything remotely close to a circumnavigation. But it will be fun to see just how far one of these might fly.
An upcoming business trip and then a vacation in the coming months makes the shipping time for this item incompatible with those plans. Maybe at a later date...