Having completed the code for the APRS/RTTY Payload I got round to making a container and an antenna for it. The 70cms antenna was just going to be the normal 1/4 wave however the 2 meter one had to be slightly different. I settled on a Slim Jim made from twin core feeder wire. Using M0UKD’s Slim Jim Calculator I quickly made one up and made a choke out of some 40mm PVC tubing.
The estimates for battery life were a whopping 70 hours for each pair of AA’s in the payload (The operating battery voltage had to be > 3V or the efficiencies on the 5V stepup started to cause issues). In the end I decided on 3 pairs of AA energizers. Enough for continuous TX for about a week.
Here you can see the battery pack on the left and the transmitters on the right.
All fastened up note slim jim hanging below. Full build pics >here<
It was all ready to go, just plug in and launch then a spanner in the works. Apparently the operation of amateur radio equipment in the air isn’t permitted in France. Maybe. With the situation becoming unclear and the launch window rapidly approaching I made the decision not to launch the payload. Instead we’d launch a PAVA board with the same code on to test the Geofencing.