SSTV FAQ

SSTV

SSTV lets you decode and display, as well as transmit, SSTV (Slow Scan TV) transmissions on your iPad, iPhone and iPod Touch. Just connect it to an HF radio (or even set it next to the radio's speaker), tune in an SSTV frequency, and watch the pictures.

A quick tour of the controls:

When Auto Start is turned on, the app will detect the start of an SSTV transmission, and begin decoding the image.

When Auto Mode is turned on, the app will decode the VIS code sent at the beginning of the transmission, and set the SSTV Mode. When off, it will use the current mode.

When Auto Save is turned on, decoded images will be saved to the Documents folder for the app. You can then use iTunes to retrieve these images from your computer:

Go to iTunes, and select your device from the DEVICES list at the left
Click the Apps tab
Under File Sharing, select SSTV from the list of Apps
All of the saved pictures will be under SSTV Documents. You can Save them to your computer, or delete them

You can also email a saved image. When viewing the image, tap the Email button, and fill out the recipient's email address, then tap send.

The Manual Start and Manual Stop buttons can be used to start and stop decoding an image. This can be handy if the signal is weak, and the app couldn't detect the start of transmission.

You can manually select the SSTV mode. Tap the mode button, and select the new mode. If you're already decoding an image, previous audio will be re-decoded for the new mode. This is handy if you need to manually set the mode due to poor signal conditions, or when you manually start decoding.

The Phase slider is used to slide the image left and right, and is normally used when decoding was manually started, since it is likely that the decoding wasn't started at exactly the correct time, and there is an offset. The Center button can be used to re-center the phase to the default value.

You can also use your finger to adjust the phase. Just touch the decoded image, and move back and forth to adjust it

The Skew slider is used to adjust the skew or slant of the image, and is used to compensate for timing differences between the sending station and this app. The Center button can be used to re-center the skew to the default value.

You can also use your fingers to adjust the slant. Touch with two fingers, and move up and down to adjust the skew.

To transmit an SSTV image, tap the Tx button. This button is only enabled when the currently selected SSTV mode supports transmitting. If it is dimmed, select a different SSTV mode.

To use an existing image, select "Select Image File From Roll" and select your image. To take a picture with the camera, select Use Camera (only available if your device has a camera)

You can then use Set Text to specify text to be added to the transmitted image, such as your callsign. The color of the text, as well as the relative size, may be selected. (Only available after you have selected an image to send)

View Image to Transmit may be used to preview the image. (Only available after you have selected an image to send)

Then tap Transmit Image to start the transmission. The image will be automatically decoded as it is sent, so you can watch the progress. (Only available after you have selected an image to send)

To use this app, you need to feed the audio output from a your radio into the device. You can do this via one of several ways:

Set the device near the radio's speaker to pick up the audio. While easy to do, this is not ideal, as background noise can interfere with the audio, causing garbled decodes.
Plug headphones into the radio, and set one earphone near the mic. I find that with good quality headphones, this can work extremely well.
Use the microphone input jack of your device, by obtaining an appopriate cable and connecting the radio's line level output to the microphone input.
With the Camera Connection Kit, you can plug a USB sound input device into the iPad, and use a patch cable between it and the radio's audio output. This is by far the best solution.

You can use the volume indicator in the upper right corner to verify that audio is getting into your device, and that the volume level is appropriate.

If you are running iOS 7 or later, be sure to give the app permission to use the microphone. If you denied permission, you can always give it again by following these steps:

Open Settings app and go to "Privacy"
Select "Microphone" to get a list of all apps that have requested access to the microphone, and to control which apps have access to the microphone

If you're looking for a radio to use with the app, there are many different types to choose from. Take a look at our listing of radios to use with your app, to see several, along with some suggestions on how to choose a radio.

That's it!

Here are some details on directly connecting an audio line source to your iPad/iPhone/iPod Touch

SSTV Frequencies

3845 (LSB)
7171 (LSB)
14230 (USB)
21340 (USB)
28680 (USB)
144500 (FM)

Email your comments and questions to support@blackcatsystems.com

Last modified January 7, 2013