It summarized: "This is a project by a serious amateur for the few other serious amateurs."
PC boards were not available so the builder had to hand wire about 140 integrated circuits! Parts cost alone was about $700.
It's a lot easier today. All of the projects here use a personal computer to do most of the work. All you need to build is some sort of interface to get audio in and possibly out of the computer.
In this chapter we'll take a quick look at several systems you can homebrew. In alphabetical order:
U1 - top view (pins pointing away from you) 25 9 notch on this end J1 name pin pin and/or dot near pin 1 ---- --- --- +----U----+ +-----+ | 1 8 | +----|--O | DTR 20 4 audio from | | | | | | | receiver -------| |---+--------| 2 7 |----+ | | | | | | | | | C1 | +----| 3 6 |---------|--O | DSR 6 6 < | | | | | > | +--| 4 5 | | | R1 < | | +---------+ | | > | | | | < | +----------------------|--O | RTS 4 7 > | | | | | | | audio ground ------------+---+------------------------|--O | GND 7 5 +-----+ Radio Shack part # $ ------- ----- U1 741 or similar op amp 276-007 0.79 R1 47K resistor 271-1342 0.39 C1 0.01 uF capacitor 272-131 0.49 J1 DB25S 276-1548 1.99 or DB9S connector 276-1538 1.29 - Shielded cable for audio ? ?There are many variations on this basic circuit. Others use diodes for reverse voltage protection, capacitors for power filtering, and/or audio transformers for breaking up ground loops. This is trimmed to the bare essentials but still seems to work well.
(The American pronounciation of E Z is like the word "easy". In other countries it sometimes comes out like "ee zed".)
Simply run the program and click on the "Recv" button or press the Enter key.
The first time you run it, it will ask about the type of interface (in plain English) and where the interface is connected. It even calibrates itself automatically from signals heard on the air.
More EZ SSTV information and download instructions.
Those with the ambition to homebrew a single interface for personal use will be rewarded with a copy of the software and a hardcopy manual from the author at absolutely no charge. Just send a photograph of the hand wired interface as proof.
Please note that this applies only to the "Classic" version as described in QST January 1993. It does not apply to the later Pasokon TV Lite which uses a trivial interface.
More details are in the chapter on PC Based Systems.
Software is available from the ARRL BBS at (203) 666 0578.
The software can be obtained from the Cookie BBS at (419) 562 6327.
Kits are available from A & A Engineering mentioned in the chapter
on PC Based Systems.
Home
Page.
Next
Chapter.
(C) Copyright 1995 John Langner.