First data from Solar Eclipse 2017
I set up a smaller version of my mad-scientist stuff at our cottage on Beaver Island, Michigan (45 38 38 N, 85 29 24 W, grid square EN75gp), to record the RF spectrum before, during, and after the eclipse on…
FTS-4100 Cesium Standard tests
It wasn't too hard for the HamSci guys to convince me to bring a Cesium frequency standard to my portable location in Michigan to drive the HPSDR receiver that will do band recordings for the 2017 Total Solar Eclipse HF…
Hermes SDR as spectrum analyzer
I was fussing about signal generator output accuracy because I wanted to calibrate my HPSDR Hermes software defined radio ("SDR") so that I could calculate the absolute power input in dBm, assuming a 50 ohm load impedance) based on the…
Update on Boring Signal Generator Stuff
Just when you thought it couldn't get more boring (reference my last post about signal generator calibration... I did all these careful calibrations of my signal generator to check its accuracy and linearity. Everything looked good, except that the signal…
Boring Signal Generator Accuracy/Linearity Data
UPDATE: it turns out that my "best" power meter was actually about 0.5 dB off. See my later post for further details. I want to calibrate my software defined radio receiver prior to doing a bunch of recordings of the…
$20 P25 Trunking Scanner (Part 4)
With op25 successfully decoding the control channel, now you just need to set up the trunking configuration. To do this, you'll probably need to set up three files: 1. trunk.tsv defines the sites to be monitored. 2. site_name.tsv provides a…
$20 P25 Trunking Scanner (Part 3)
The info in this and in part 4 was aided tremendously by several folks on the "op25-dev" mailing list. Without their help, I would not have even known where to start in getting my system running. I hope that what…
$20 P25 Trunking Scanner (Part 2)
Here's how to install the OP25 scanning software. If you don't already have Gnuradio installed on a Linux system, do those two things first. Any current Linux distribution works. I use Linux Mint which is very similar to Ubuntu. The…
$20 P25 Trunking Scanner (Part 1)
A couple of weeks ago at the Dayton Hamvention I bought a fancy Whistler TRX2 scanner that can receive the new P25 digital trunking system that's been rolled-out statewide here in Ohio. Unfortunately, after a lot of attempts, I still…
Pulse Per Second Dividers, Overdone
Several years ago I designed a little circuit board called the T2-Mini that provides life support for one of Tom Van Baak's very wonderful picDIV PIC-based frequency dividers. The idea is to convert the 1, 2.5, 5, or 10 MHz…