Tagged: SSTV

SSTV from the International Space Station Scheduled for Dec 24 – Dec 31

Thank you to Maksim for submitting news that the International Space Station (ISS) will be transmitting Slow Scan TV (SSTV) in late December to celebrate 20 years of amateur radio operations onboard the space station. The ISS periodically transmits SSTV images during special events throughout the year. You can keep up to date on the ISS SSTV schedule on the ARISS-SSTV site.

An ARISS Slow Scan TV (SSTV) event is scheduled from the International Space Station (ISS) for late December. This will be a special SSTV event to celebrate the 20th anniversary of ARISS operations on the ISS. The event is scheduled to begin on December 24 and continue through December 31. Details to follow later. Dates are subject to change due to ISS operational adjustments.

With an RTL-SDR and a simple V-Dipole from our RTL-SDR Blog V3 antenna kit it is possible to receive these images when the ISS passes over. ISS passes for your city can be determined online, and the SSTV images can be decoded with a program like MMSSTV.

An example SSTV image from the last ISS SSTV event
An example SSTV image from an SSTV event held in previous years.

New SDRUno Plugin Video Demos: Frequency Annotation, WEFAX, SSTV, DXToolbox

Earlier this year SDRplay updated their SDRuno software to have plugin functionality. This allows third party programmers to implement their own decoders and software which interfaces with SDRuno directly. Recently we've seen some new plugins become public, and in one of their recent blog posts, SDRplay highlights a few new ones.

SDRplay writes the following about three demonstration videos:

The first shows the latest version of FRAN – a FRequency ANnotation programme, developed by Eric Cottrell – it can read SWSKEDS or .s1b memory bank files and display the active stations from the files on the main spectrum window. This is an example of a Community Plugin

Quick Look at the FRAN Plugin (VID558)

FRAN complements the DX Cluster demo plugin provided by SDRplay. This programme displays DX cluster callsigns on the SDRuno spectrum display. A DX cluster is a network of computers, each running a software package dedicated to gathering, and disseminating, information on amateur radio DX activities. With this plugin you can overlay the DX cluster callsigns as they pop up. There’s a choice of how long you let them display and you can control the way in which they appear. Here we show it successfully tuning in to a US station flagged by the cluster. (The receiver was in the UK):

Quick Look at the DXcluster Plugin (VID560)

Finally there’s this new video showing the new plugin for interfacing the software suite from Black Cat Systems to SDRuno enabling DXToolbox, HF WEFAX and Slow Scan TV decodes:

Quick Look at the Black Cat Systems plugin

Black Cat Systems has a range of software available – more information can be found at: https://blackcatsystems.com/ For more about the SDRuno plugin system for both users and potential developers, go to https://www.sdrplay.com/plugins/

International Space Station SSTV Event Scheduled for October 9 and 10

The International Space Station (ISS) periodically schedules radio events where they transmit Slow Scan Television (SSTV) images down to earth for listeners to receive and collect. This time they have scheduled SSTV images for October 9 09:50 - 14:00 GMT and October 10 08:55-15:15 GMT.

With an RTL-SDR and a simple V-Dipole from our RTL-SDR V3 antenna kit it is possible to receive these images when the ISS passes over. ISS passes for your city can be determined online, and the SSTV images can be decoded with a program like MMSSTV.

AMSAT-UK writes:

Russian cosmonauts are expected to activate Slow Scan Television (SSTV) image transmissions on 145.800 MHz FM from the International Space Station on Wednesday/Thursday, October 9/10.

This is the schedule for the planned activation of the MAI-75 SSTV activity from the ISS.
• Oct 9 09:50-14:00 GMT
• Oct 10 08:55-15:15 GMT

Transmissions will be sent on 145.800 MHz FM in the SSTV mode PD-120. Once received, images can be posted and viewed by the public at http://www.spaceflightsoftware.com/ARISS_SSTV/index.php

ISS SSTV uses a Kenwood TM D710E transceiver which is part of the amateur radio station located in the Russian ISS Service Module.

Please note that SSTV events are dependent on other activities, schedules and crew responsibilities on the ISS and subject to change at any time. You can check for updates regarding planned operation at:
ISS Ham https://twitter.com/RF2Space
ARISS Status https://twitter.com/ARISS_status
ARISS SSTV Blog https://ariss-sstv.blogspot.com/
AMSAT Bulletin Board http://www.amsat.org/mailman/listinfo/amsat-bb

Read the MagPi article Pictures from space via ham radio
https://www.raspberrypi.org/magpi/pictures-from-space-via-ham-radio/

ISS SSTV info and links https://amsat-uk.org/beginners/iss-sstv/

Slow Scan Moon Bounce Event for 50th Anniversary of the Moon landing

Fifty years ago Neil Armstrong became the first man to step foot on the moon. This weekend on June 20th and 21st 2019 Amateur Radio operators at the [PI9CAM] team have been transmitting Slow-Scan Television images in commemoration of this historic event at the Dwingeloo radio astronomy station in the Netherlands. This station is the oldest rotatable 25-meter radio telescope in the world. 

 Dwingeloo radio astronomy station
Dwingeloo radio astronomy station
An EME SSTV Image
An EME SSTV Image

Slow-Scan Television is a method often employed by ham radio operators to send photos over radio waves. You may be familiar with this from some of our previous articles on the SSTV event held by ARISS for the International Space Station.

Station [S1NDP] has previously sent slow-scan EME images between the PI9CAM team and himself. These images can potentially be heard by anyone within line-of-site with the moon during the operation of this event.

The team transmit in the 23cm band at a frequency of 1296.11 MHz, according to the ARRL even a 2.5 to 3meter dish should be enough for reception assuming you have a 23cm feed for your dish. It will be interesting to see what photos are heard by the end of this event.

Next International Space Station SSTV Event on April 11 – 14

Thank you to Alex Happysat for writing in and letting us know about the next upcoming ISS SSTV event which will begin on 11 April at about 18:00 UTC and end on 14 April 2019 18:00 UTC. If you were unaware, the International Space Station (ISS) transmits SSTV images several times a year to commemorate special space related events. SSTV or Slow Scan Television is an amateur radio mode which is used to transmit small images over radio signals.

The images will be transmitted constantly at 145.8 MHz over the active period and they are expected to be in the PD-120 SSTV format. To receive the images you can use a simple RTL-SDR dongle and the MMSSTV software. A tuned satellite antenna like a QFH, turnstile, or tracking Yagi would be preferred, but many people have had good success before using simpler antennas like a V-Dipole. Software like Orbitron, GPredict, various Android apps or NASA's Spot the Station website can be used to determine where the ISS is and predict when it will be over your location.

Over on the ARISS SSTV blog, they write:

The next big event will be the ARISS SSTV event that starts Thursday, April 11 about 18:00 UTC and will be operational until about 18:00 UTC on Sunday, April 14. Since this event will run continuously for 72 hours, folks in the higher latitudes should have a pretty good chance to receive all 12 of the images. Operators in the mid latitudes should be able to get most of them depending on location. Good Luck and Enjoy!

Alex also mentions that for this and other ISS events AMSAT Argentina is handing out ARISS-SSTV Diplomas to amateur radio operators who receive, record and upload at least 15 images received from the ISS, in at least two different radio operation with a month or more in between then.

If you cannot set up a receiver, it is possible to use R4UAB's WebSDR which will be available directly at websdr.r4uab.ru. However, note that internet reception is not valid for the AMSAT Diploma. An example of WebSDR SSTV reception and decoding from a smaller ISS SSTV event held a few days ago is shown below.

ISS SSTV R4UAB WEBSDR 12.04.2016 14:00 UTC

SignalsEverywhere: SDRAngel PlutoSDR Transmit Tutorial

Over on his YouTube channel SignalsEverywhere, Corrosive has uploaded a new video tutorial showing us how to transmit with a PlutoSDR and SDRAngel. His tutorial goes over the initial set up steps, selecting a modulator and changing modulator settings. He then goes on to demonstrate transmitting CW Morse code, using a CTCSS squelch tone and transmitting a Robot36 SSTV image via Virtual Audio Cable and MMSSTV.

SDRAngel Transmit Tutorial with PlutoSDR

RPiTX v2 Released: Easily Record and Replay with RTL-SDR and a Raspberry Pi

RPiTX is software for the Raspberry Pi which can turn it into a 5 kHz to 1500 MHz transmitter which can transmit any arbitrary signal. In order to transmit the software does not require any additional hardware apart from a wire plugged into a GPIO pin on the expansion header. It works by modulating the GPIO pin with square waves in such a way that the desired signal is generated. However, although additional hardware isn't required, if RPiTX is to be used in any actual application a band-pass filter is highly recommended in order to remove any harmonics which could interfere and jam other radio systems.

Earlier this month RPiTX was upgraded to version 2. One of the changes is a new GUI for testing the various transmission modes. Currently it is possible to transmit a chirp, FM with RDS, USB, SSTV, Opera, Pocsag, SSTV, Freedv. There is also a spectrum painter which allows you to display an image on a SDR's waterfall.

The RPiTX V2 GUI
The RPiTX V2 GUI
Painting an Image on a SDR Waterfall Display with RPiTX v2
Painting an Image on a SDR Waterfall Display with RPiTX v2

The RPiTX v2 update also makes recording a signal with an RTL-SDR, and replaying that signal with RPiTX significantly easier. Previously it was necessary to go through a bunch of preprocessing steps (as described in our previous tutorial) in order to get a transmittable file, but now RPiTX is capable of transmitting a recorded IQ file directly. This makes copying things like 433 MHz ISM band remotes significantly easier. One application might be to use RPiTX as an internet connected home automation tool which could control all your wireless devices.

Finally, another application of the RPiTX and RTL-SDR combination is a live RF relay. The software is able to receive a signal at one frequency from the RTL-SDR, and then re-transmit it at another frequency in real time. Additionally, it is also capable of live transmodulation, where it receives an FM radio station, demodulates and then remodulates it as SSB to transmit on another frequency.

The RPiTX V2 RTL-SDR Menu
The RPiTX V2 RTL-SDR Menu
RPiTX v2 re-transmitting a broadcast FM signal live at 434 MHz.
RPiTX v2 re-transmitting a broadcast FM signal live at 434 MHz.

A Tutorial on Receiving HF SSTV with a Raspberry Pi and RTL-SDR V3

Thank you to Giuseppe (IT9YBG) who has written in to share his tutorial about setting up a direct sampling RTL-SDR V3 based SSTV receiver on a Raspberry Pi. He writes that he uses the receiver to continuously receive images at 14.230 MHz, but with a frequency tweak in the command line code the system could also be used to receive the VHF SSTV images sent by the ISS.

In the tutorial he uses the free QSSTV software for decoding. An RTL-SDR together with the CSDR DSP software is used to set up a command line based receiver, which pipes the SSTV audio into a virtual audio sink, and then into QSSTV. The receiver setup procedure is similar to the method used in our RTL-SDR V3 QRP monitoring station tutorial, and is a very nice way of setting up an efficient command line based RTL-SDR audio output.

QSSTV Running on a Raspberry Pi with RTL-SDR V3 Radio
QSSTV Running on a Raspberry Pi with RTL-SDR V3 Radio