Going with cheap Chinese polysilicon solar cells over Powerfilm. The difference between the two in weight is: polysilicon – 3.75 g, Powerfilm is 6.7 g. The cost difference is enormous. The polysilicon is incredibly fragile. The flat connecting wire is called “tabbing” wire and comes pre soldered. I tried using a soldering iron and found it like working on potato chips. I moved on to solder paste with a hot air tool and am getting great results. The problem is once I get everything put together, I inevitably break a cell. I need to figure out how to get from workbench to launch without breaking it.
The image below from the HYSPLIT forecast shows the projected paths, provided courtesy of Bryan KF6ZEO.
We launched the balloon at approximately 9:50am PDT.
There was a fair amount of fog, so we decided to wait until it would clear some. After waiting about 40 minutes, we launched the balloon with fog still present. The balloon ascended at a promising rate and went mostly straight-up.
Folks present at the launch in person included Martin W6MRR, Rob NZ6J, and Robert K6RGG.
SF-HAB will be launching a high altitude pico balloon on the morning of Saturday, September 4, 2021 at 9:00am PDT, at the Berkeley Marina in Berkeley, California. It will be carrying a custom-built Amateur Radio payload that reports position and altitude using the popular WSPR mode on 20m. We look forward to the launch and welcome folks to join in person.