My WSPR signal report on iPad WSPR Watch app
I’ve been intrigued by WSPR beacons as a way to track and explore changing HF propagation from my QTH. However, most of the options for this require a computer at the radio desk, usually a Windows machine, and more technology than I was interested in getting into for this project. The WSPR Desktop Transmitter from zachtek.com requires none of this. It is a tiny standalone 200 mw WSPR beacon that once configured with your computer, can run on its own. You can then track propagation from your location on whatever HF bands you select, using websites or an app for your device.
Although the configuration software that to be downloaded from the site is Windows based, the transmitter can be configured from any computer using Chrome at this website:
https://webserial.nfshost.com/. Once configured, the transmitter can continue to be run from the computer, or it can be powered by a USB supply of at least 300W.
The one downside I’ve experienced is that when transmitting, it puts out quite a bit of wide-band interference, especially on the CW segments of the band, that show up on nearby receivers. For this reason, I turn my beacon off when operating from the shack when the beacon is located.
There are a number of ways to monitor where your beacon is being received. The WSPR Watch app for iPad and iPhone is very handy. The following web site, located in Argentina, can be a bit slow to load but contains very useful signal reports and map: http://lu7aa.org/dx.asp? This site is also useful: http://wspr.aprsinfo.com/
The beacon could be switched to your transmitting antenna for the appropriate band when you are not operating your rig. However, I have mine connected to my backup antenna, a low multi-band endfed.
Below is Zach Control using a Chrome browser on Mac. To use it, select WSPR at top left, then Open Serial and choose the serial port. Next, select the bands you want to monitor. A GPS antenna comes with the transmitter and will need to be outside where it can see satelittes for location and timing. The satelitte signals that mine is receiving can be seen on the right. Select TX On and when the timing is right, the beacon will start transmitting and cycle every few minutes. Active transmission is indicated by red in the transmitter output box below but also by a green light on the transmitter itself; the latter is especially usefully when running the beacon as a standalone unit.
The documentation provided by Zachtek is excellent and doesn't need to be repeated here.