Friday, December 28, 2018

Getting Started with Digital Modes (WSPR)

Weak Signal Propagation Reporter


Discovering digital modes for the first time, I found WSPR is a great mode to start with as you can simply start listening for and decoding beacons right away, and have your mind blown at how far away these weak signals can be received when you cant hear anything audibly out of the speaker!

This doesn't cover how to configure the software and radio. There are plenty of guides and docs around on how to get WSJT-X communicating with your rig.

My hope is to capture enough data from the WSPRnet.org database to start building a picture of how well my station transmits and receives signals on HF compared to others by looking at distance per watt stats etc.



I have spotted ZS3D several times over the last few days on 40m at a distance of 16, 233km / 10, 087 miles, and today ZS1OA on 30m, slightly further at 16, 511 km / 10, 259 miles! These stations are probably about as close as I'll get to hearing something from my antipode.



A surprise when I spotted beacons from stations on 630m (472kHz) in Northern California and BC!

After a few email exchanges with Joe NU6O, I learned that 630m propagates best with vertical polarization. Joe is using a 43ft vertical near salt water, 100W transmit power to radiate 1W EiRP [Antenna is 1% efficient], his beacons are regularly decoded in Japan across the Pacific.

I'm only spotting stations nearby on 630m because I'm using a Carolina Windom 80, less than ideal for this band being a horizontal wire with out any matching / loading for 630m, its kinda surprising I heard anything at all.

WSPR can also be used to indicate the possibility of using other modes based on the reported SNR, see https://www.qsl.net/kp4md/wsprmodes.htm

Update Jan 03 2019:

Transmitting beacons yesterday..



Heard by DP0GVN in Antarctica on 30m [10Mhz]!



Heard by ZL3003SWL in New Zealand on 15m [21MHz]!

A couple of other surprises transmitting a few beacons using 50W at one point on 12m [24.9MHz] and 10m [28MHz], I was heard in California when you'd think these bands were otherwise completely closed for voice modes.