Since my new Wouxun has audio output jacks, I figured it would be useful to have the ability to record what my rig hears, if anything interesting comes on the air.
Under Linux, I use an application called, (creatively enough), Audio Recorder.
Using a simple connection to the mic input on a USB soundcard, I can capture everything the radio hears. Unfortunately this doesn’t work for outgoing audio, so it’s not much good at capture of my personal QSOs. For this I will have to set up another radio to act as the main receiver.
At some point in the future I will implement this with a Raspberry Pi as the audio capture server.
I have recently come across the software the Wouxun factory uses to set the band limits on the KG-UV950P.
While the software is in Chinese, it’s functional, and allows setting of all band limits on the radio.
Here’s an English version of the interface:
Note when using this software:
This possibly has the potential to damage the radio, if you transmit on a frequency it’s not designed for. Not to mention the legal issues with transmitting on frequencies that aren’t permitted! Use at your own risk!
I recently posted about a small analog SWR/Power meter I got from eBay, and figured it needed some improvement.
After some web searching I located a project by ON7EQ, an Arduino sketch to read SWR & RF power from any SWR bridge.
The Arduino code is on the original author’s page above, his copyright restrictions forbid me to reproduce it here.
I have also noticed a small glitch in the code when it is flashed to a blank arduino: The display will show scrambled characters as if it has crashed. However pushing the buttons a few times & rebooting the Arduino seems to fix this. I think it’s related to the EEPROM being blank on a new Arduino board.
I have run a board up in Eagle for testing, shown below is the layout:
The Schematic is the same as is given on ON7EQ’s site. Update: ON7EQ has kindly let me know I’ve mixed up R6 & R7, so make sure they’re switched round when the board is built ;). Fitting the resistors the wrong way around may damage the µC with overvoltage.
Here’s the PCB layout. I’ve kept it as simple as possible with only a single link on the top side of the board.
Here’s the freshly completed PCB ready to rock. Arduino Pro mini sits in the center doing all the work.
The link over to A5 on the arduino can be seen here, this allows the code to detect the supply voltage, useful for battery operation.
On the right hand edge of the PCB are the pair of SMA connectors to interface with the SWR bridge. Some RF filtering is provided on the inputs.
Trackside view of the PCB. This was etched using my tweaked toner transfer method.
Here the board has it’s 16×2 LCD module.
Board powered & working. Here it’s set to the 70cm band. The pair of buttons on the bottom edge of the board change bands & operating modes.
As usual, the Eagle layout files are available below, along with the libraries I use.
More to come on this when some components arrive to interface this board with the SWR bridge in the eBay meter.