Nuts and Volts - June 2017

WSPR, JT9, and JT65

These modes are used for weak signal communication. Oftentimes, these signals are so weak they are not perceptible by ear. These modes are used in special segments of the ham bands. For example, WSPR can be found on 14.095600 MHz and JT65 can be found on 14.076000 MHz. Note the precision of the dial settings. See Figure 6 for a JT65 screenshot.

Included with the programs are dial frequencies for all bands. WSPR has its own website for reporting spots, while JT9/JT65 uses PSKreporter. These programs can be found at www.physics.princeton. edu/pulsar/K1JT.

Weak signal modes require coordination of your PC with Universal Coordinated Time (UTC) to within one or two seconds. Make sure to set your computer clock accordingly and check it often.

Software for FAX, SSTV, and EasyPal

FAX can be received with MULTIPSK or Fldigi. Figure 7 shows a satellite image received with MULTIPSK. It is over the Pacific Ocean south of Mexico. The picture has several breaks — probably caused by errant Internet packets as mentioned earlier.

Nonetheless, receiving these FAX images is interesting and gives you an idea of how many packets are lost over time.

Fax signals can often be found around 12.748 and 12.788 MHz. Slow scan TV signals can be found around 14.230 MHz. Several programs are available on the Internet for SSTV including MULTIPSK.

One of the newer picture modes is EasyPal, which transmits pictures digitally. It can be found at 14.232

MHz. Perfect pictures can be received if the signal manages to make it through the noise. Search for it on the Internet.

Final Comments

It can be challenging to utilize radio receivers located around the globe. Hopefully, you have learned a little bit about how to receive and decode Web based shortwave data signals.