The University of Nevada, Reno
Nevada Space Grant
Student
High-Altitude Ballooning

NV SGC
This program is generously supported by the Nevada Space Grant Consortium


Site Navigation:

BalloonSAT Home
Equipment
Antennas
Balloons
Cameras
Connectors
Carabiners
Data Loggers
GPS
Heaters
Parachutes
Payloads
Power Supplies
Radios
   Yaesu VX-2
   MicroTrak 300 
   Kenwood TM-D700
   Kenwood TH-D7
   Alinco DJ-C4T
   Alinco DJ-C5T
Forms


Missions

 


Max Transmitting Power: 300 mW

This is the radio we currently use for our secondary communications payload. It pre-set to the national APRS frequency (144.390). We typically transmit once every 2 minutes. Since we are using the national APRS frequency, we can check findu.com for the last reported position. We only check online when loose track of the balloon during the chase (an iPhone comes in handy for checking online). This also allows other not at the launch to monitor the balloon's progress in near-real time. We use a home-made J-Pole antenna with the MicroTrak. Even with the high gain of the J-pole antenna, we typically get a "ping" from the secondary communication payload when we are within a mile of a the payload lying on the ground.

Many other BalloonSat's use this as their primary radio. We are not that brave...

Pros:

This radio is extrememly small and light. Our tests show we can run the radio and GPS for over 17 hours on an 8 pack of AA Energizer Lithium batteries (12V).

Cons:

We found out the hard way that the MicroTrak reports the last known GPS location, even if a GPS is not connected to it. During one launch, we thought we had GPS lock (the reported position was the launch site) but in reality it didn't. ALWAYS make sure the APRS is reporting altitude  as well as position (Lat/Lon). The TinyTrak will not report altitude if there is no GPS lock.