ATV Add-ons.

"Low cost caption generator" by Steve Drury G6ALU	"4-Input Vision Selector" from the ATV Compendium	"Video fader & audio mixer" CQ-TV 140	"PIC Caption Generator" by Alain Fort

"Test Card Generator" The Cropredy	"Video Distribution Amp" using discrete circuits	"VOGAD" using SL6270	"An alternative VOGAD" that doesn't use the '6270

My diecast box opened up. Note the 'double' EEPROM & switch. (see close-up)	This is the high quality pcb provided by Steve and the Milton Keynes club.

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I made mine on a pcb designed by Howard, G3NZL, for the SCART club. The PIC, a 16C84, was kindly programmed for me by Dave, G0GMK. I wanted to use mine away from the shack (and the +12 volt PSU) so I have put a 9v battery (PP3) inside the box. A switch enables me to either select the internal battery or an external nominal 12v, in which case the LED lights to show it is powered. I have found that its small size and internal battery makes it an extremely useful video source for testing all kinds of video equipment like monitors and ATV TXs. I don't find the internal clock much use as it has to be set each time power is applied; I will probably try to use that part of the screen (and program) for something else. I also intend to add a colour coder but this may make it too big for the existing diecast box as well as run the battery down even faster! Rather than modify this unit I will make a second one in which to try out these ideas.

This is how I have boxed my Cropredy. From Left to Right are: The EPROM select switch (not yet used) Test tone (not yet used) Power ON/OFF and red LED 75 Ohm Video out.

Here you can easily see the EPROM with blue label. It is held in a 28-pin ZIF socket. The intention is to add a pcb with several EPROMs that can be selected by the rotary switch on the front panel. The small experimenter's board at the lower Right is the colouriser circuit (CQ-TV 139 p20-23). The BNC socket on the back panel (upper Right) will be used for audio out from a test oscillator or even a callsign generator. At the moment it is used for a 'scope trigger pulse.

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Vogad unit with electret mic.

The 'kit' completed and working.	Mounted in a modified diecast box and still working well!