Category Archives: Digital

Articles and Information related to Digital Modes. Topics include PSK, RTTY, JT Modes, APRS, operating using Digital Modes, equipment, software, and more.

FT8 DXpedition mode

You have probably heard something about recent efforts to develop a special “FT8 DXpedition Mode” in WSJT-X. This message aims to bring you up-to-date on our  progress, and generally to make our plans more widely known.

Source: FT8 – DX Pedition mode

It looks like some of the major DXpeditions are beginning to embrace FT8. This will certainly create a need to handle “pileups” in FT8 mode and to make it possible to make many contacts in the shortest period of time possible. It appears that Joe Taylor, K1JT is working on an update to WSJT-X to create a variation of FT8 tailored for DXpedition use. Also, we will also need to update our copies of WXJT-X to take advantage of the new FT8 DXpedition mode. The link above is an article by Joe which gives more information about his new FT8 DXpedition mode and the software which will support it.

Fred, AB1OC

Receiving SSTV From The ISS

We’ve recently upgraded our Portable Satellite Station 2.0 to add digital and packet capabilities. The upgrade was pretty simple – we added a SignaLink USB Soundcard and a Windows Laptop PC. Most of the software for Packet and Digital Amateur Radio communications is written for the Windows OS so using a separate laptop running Windows 10 was the simplest way to go.

Portable Satellite Station With Additions For Digital and Packet
Portable Satellite Station With Additions For Digital and Packet

Another benefit of the second laptop was added screen space to use when doing packet communications via satellites and the International Space Station (ISS).

Receiving SSTV From The ISS

SSTV Image From The ISS
SSTV Image From The ISS

We recently learned that the ISS was going to be again transmitting SSTV images worldwide. This provided a perfect opportunity to work with the digital additions in our satellite setup. We downloaded and installed MMSSTV on our Windows laptop and set the audio levels on the Windows PC and our SignaLink Sound card to properly receive SSTV signals. The MMSSTV application can decode several different SSTV formats including the PD120 format used by the ISS. The ISS transmits SSTV on a 2m FM voice channel. We configured MacDoppler to track the ISS and perform doppler correction on the 2m ISS 2m downlink and began to listen.

The video above was made during the reception of an SSTV image from the ISS during a pass over the United States. The video gives a good idea of what its like to receive SSTV from the space station.

More ISS SSTV Images…

Another SSTV Image From The ISS
Another SSTV Image From The ISS

We were able to receive several different images from the ISS during the period that it was transmitting SSTV worldwide.

A Third SSTV Image From The ISS
A Third SSTV Image From The ISS

It was pretty easy to capture the SSTV transmissions from the ISS with our Portable Satellite Station 2.0 setup. The signals were strong and I would imagine that the SSTV transmission could have also been received with a simple portable satellite setup with a hand-held yagi antenna.

We hope that the ISS will send SSTV images again in the near future. It was fun receiving them.

Fred, AB1OC

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