ChromaPIX Version 1.0fc1 Changes and new features

FLASH:
ChromaPIX 1.0fc1 Build 006 was posted on 9 September, 1999.

Note:
Version 1.0fc1 contains major updates to most of the program components. Please review the listings below for details.

SSTV Repeater (General)

• Designed for "quiet" bands. I.E., 10m,6m,2m, etc.
  To ensure compatibility with other systems, we used the standard 1750hz repeater tone. Because of this, stray signals and 'tuner uppers' can cause undesired repeater operation on busy HF frequencies. If you use the repeater, PLEASE use it responsibly, and according to the regulations and "gentlemen's agreements" that apply in your part of the world. For example, in the US, it is not legal (or very friendly) to operate an unattended repeater on 20 meters.
• Repeater tone requirements
  1750hz, +,- 100hz, <10% distortion, >=18db S/N. A valid tone must be detected for 1.5 seconds or longer, followed by at least 1 second of "no tone". Please note that the 18db S/N figure is above internal system noise. This can be an issue if you are using very low-level audio inputs, or a sound card with a poor noise figure. A good rule of thumb for audio inputs is that ChromaPIX will perform best overall if the average (not peak) audio level is between 10 and 40% on the internal level meter. It will still work at lower and higher levels, but this is the range to try for.

SSTV Repeater (Operation)

• Listen mode
  Any valid SSTV picture will be received, and will replace the last image received. These received pictures will not be repeated.
• Query mode
  If a valid repeater trigger tone is detected, (1.5 seconds minimum @ 1750hz) the repeater will send back a CW 'K'. During the next 10 seconds, if no SSTV signal is received, the last picture received will be transmitted, in the original mode it was received in. Because of the wide variety of modes, and the differences in software, repeater operators may want to at least consider locking to a specific mode.
• Store-and-resend (normal) mode
  If a valid repeater trigger tone is detected, and a SSTV signal begins within 10 seconds, that picture will be repeated 10 seconds after it is completely received. The 10-second delay before re-transmission is intended to allow the sending station time to identify, and switch back to receive.

New Modes

• SSTV and FAX modes
  "PD" 50,90,120,160,180,240,290
  Note that the PD-290 mode uses an 800x600 image window, and will require that your video display be set to 1280x1024 for it to display without scroll bars. The remaining "PD" modes are either 320x256, or 640x480.
  FAX480
  FAX480 is a high-resolution monochrome (grayscale) FAX mode, invented by Dr. Ralph Taggart, WB8DQT. It operates in a 512x496 window, (512x480 without header/phasing area) and is quite good for exchanging grayscale images, schematics, etc. Please note that ChromaPIX will receive FAX480 only if that mode is selected from the mode list. This was done to conserve CPU time, and to provide a division between SSTV and FAX modes. Conversely, ChromaPIX will ignore "standard" SSTV signals if FAX480 is the selected mode.

Other additions/changes

• Half-duplex (store and forward) SSTV repeater functions (see above)
• The four "image history" buttons now behave the same way as the image tray thumbnails, (drag/drop) and are affected by the "load effects" buttons.
• Receive cursors are now displayed during image reception, along the edges of the main window.
• CW ID now works with full-duplex TX, if enabled.
• New TX "slide show" operation will send all images in the current image tray, with a selectable delay between transmissions. If a selection rectangle is active, then the images will be scaled to fit the rectangle before TX starts. Border and drop-shadow load effects also apply, if selected.
• SSTV modes can now be changed during RX operations.
• New 'Autosave Name Options' - Can use 'CPIX+index', 'Long Date/Time', 'Short Date+index', or a custom 'name+index'. The index counter start value can also now be directly set.
• The transmit stamp can now be positioned either at the bottom left or right, and can be set to include the current date and/or time, and/or the station callsign.
• A new preference permits the SSTV modes of all front panels to track each other.
• Many minor bug fixes, and operational enhancements.

ChromaPIX Programmer's API (Applications Programming Interface)

As of version 0.96.15 and later, ChromaPIX supports an external programming interface. This interface will allow third-party Windows programs to control ChromaPIX, and command it to perform most of the basic functions. If you are a Windows developer, and would like a copy of the API, please contact us. We'll be happy to provide the details.

Back to the ChromaPIX download page

(1997-1999) Silicon Pixels