I figure the hams on this forum will appreciate this.
It's that time of year again where my local club hosts it's fox hunt. Well, unfortunately it got cancelled, but not before I finished this project.
Last year, I picked up a KerberosSDR in the first run on whatever crowdfunding platform it used. It sat on a shelf until last month, when someone said "hey, let's go do this fox hunt". That was the motivation I needed to start putting the KSDR to good use.
I had to find a way to mount four equidistant antennas on the roof of my car. On a typical metal roof vehicle, this is pretty easy, just break out a tape measure and some magnetic mount antennas, easy peasy, call it a day. My Tesla has a glass roof (with sunroof, if that matters at all), making this a much more fun engineering challenge. I made some measurements of the roof rack mounting points and put in an order with an aluminum supplier. The parts took some time to come in, leaving me just 5 days to get it all put together. After a bunch of drilling and a few trips to the local hardware store, I finally completed a roof rack, which holds a square aluminum plate. I ended up opening the rear passenger window a little bit to pass the cables for the antennas into the car. I'm not sure I'll ever be able to use this thing in the rain.
When the array is stationary, I get good bearings off of it. In the image below, I was DFing the local NOAA weather transmitter. You can ignore the lines on the right-most side of the image, those were before my tablet realized it wasn't at home anymore. I was also able to DF aircraft and the transmitter for the tower at the local airport.
When the car is moving, the antennas sway too much in the wind, causing the readings to be all over the place. Hopefully I can find a way to work through that problem.
It's that time of year again where my local club hosts it's fox hunt. Well, unfortunately it got cancelled, but not before I finished this project.
Last year, I picked up a KerberosSDR in the first run on whatever crowdfunding platform it used. It sat on a shelf until last month, when someone said "hey, let's go do this fox hunt". That was the motivation I needed to start putting the KSDR to good use.
I had to find a way to mount four equidistant antennas on the roof of my car. On a typical metal roof vehicle, this is pretty easy, just break out a tape measure and some magnetic mount antennas, easy peasy, call it a day. My Tesla has a glass roof (with sunroof, if that matters at all), making this a much more fun engineering challenge. I made some measurements of the roof rack mounting points and put in an order with an aluminum supplier. The parts took some time to come in, leaving me just 5 days to get it all put together. After a bunch of drilling and a few trips to the local hardware store, I finally completed a roof rack, which holds a square aluminum plate. I ended up opening the rear passenger window a little bit to pass the cables for the antennas into the car. I'm not sure I'll ever be able to use this thing in the rain.
When the array is stationary, I get good bearings off of it. In the image below, I was DFing the local NOAA weather transmitter. You can ignore the lines on the right-most side of the image, those were before my tablet realized it wasn't at home anymore. I was also able to DF aircraft and the transmitter for the tower at the local airport.
When the car is moving, the antennas sway too much in the wind, causing the readings to be all over the place. Hopefully I can find a way to work through that problem.
