Launch 20-Feb-2017
Transmitter photos

Jim N2NXZ launched the U3S-7 balloon flight on 20-Feb-2017.

Jim uses a standard Ultimate3S firmware, unlike Dave VE3KCL who uses the special firmware with the telemetry WSPR message. Jim is using the standard U3S configured to send WSPR and JT9 on 30m, and 20m WSPR. His construction is interesting (see below) as he uses just the v3.10a firmware chip wired to the Si5351A Synth and GPS, without any U3S PCB, for weight saving. The power output is something like 10-20mW. The transmission format is as follows: 30m WSPR x 2 followed by 30m JT9 x 3 (Grid,altitude,speed), 20 WSPR x 2 (2 minute pause,repeat). The JT9 signal can be found 100hz about 30m WSPR segment at the same dial frequency of 10.138.70 mhz USB. 


Nothing has been heard from U3S-7 since 21-Feb-2017 15:36 UT so presumably it went down somewhere in the Atlantic. RIP.

U3S-7 woke up on 21st Feb and started transmitting. KP3FT sent JT9 telemetry reception indicating an altitude of 9744m and speed of 64 knots. The last receptions on 21st Feb were at 15:36 UT. 


Jim N2NXZ launched the U3S-7 balloon flight on 20-Feb-2017 from his ROOF! An even more daring launch! 

Transmitter photos

Jim's transmitter construction is interesting. The transmitter uses a standard QRP Labs Si5351A Synth and a uBlox GPS board. The Ultimate3S is a regular bare v3.10a firmware chip wired to the other modules with enameled copper wire!