Tuesday, June 23, 2015

Field Day Logging

Field Day is next Saturday so I spent some time this last weekend preparing the logging PC's. We have been using the N3FJP logging package for years. It supports older PC's like the old Dell D600's that we use.

Saturday, June 13, 2015

APRS Balloon Payload 2

A small wood frame has been built for the APRS tracker that will be placed in a foam box. The GPS receiver is mounted at the top of the frame facing up and the transmitter and tracker boards are below. It is sitting on top of the battery pack. The plan is to use lithium AA batteries. The pack is a 6 cells which should deliver 9 volts.

I am working on the dipole antenna that will be mounted to the side of the foam box. I also need to setup a regulator for the transmitter since 9 volts exceeds it's max voltage.

Wednesday, June 10, 2015

APRS Balloon Tracker

This last weekend I lashed up the components for the new APRS balloon tracker. All the items were obtained from ArgentData:

Tracker3 Model T3-Mini

ADS-GM2 GPS Receiver

SRB MX145 Transmitter

With 5 volts running everything and the transmitter connected to a dummy load I had approximately 200 mW output. The T3 audio out was connected directly to the audio in on the transmitter. I have not yet verified the deviation level but I was able to decode with a local receiver. Later I connected the transmitter to my 2 meter ground plane and the tracker was heard on the APRS-IS network and here is the APRS.fi raw log:

Next step is build a chassis to mount the boards in the payload box and to verify the deviation level. I have found a great method to measure deviation using a SDR dongle HERE.