SV1UY's 128 Line Homemade RAM SSTV converter
In 1985 I built this 128 Line BW/Colour RAM SSTV converter by modifying a design from G3WCY and G4ENA, both members of BATC (British Amateur Television Club). G3WCY had designed the receiving part and G4ENA the transmitting part of this design.
This converter used 2 PCBs with 80 TTL and CMOS chips in total. It has 3 memories (RAM) where 3 X 128 line Black and White SSTV pictures can be stored either from the receiver to be viewed or captured from a CCTV Camera ready for transmission. Only one Colour SSTV Picture can be stored if the 128 line Colour Sequencial mode is used. The 1st RAM (memory) stores the Red Picture, the 2nd stores the Green Picture and the 3rd stores the Blue picture.
For capturing and transmitting SSTV pictures I used a Phlips CCTV camera connected to this converter.
I also used a SPECTRUM home computer, with a small interface, and a crude SSTV program by G1FTU which was perfect for creating and transmitting SSTV captions such as CQ CALLS and any kind of text one wanted to transmit on the air, i.e. operator name, station information and so on. SSTV picture reception in a SPECTRUM computer was not fantastic so I used my Hardware 128 Line SSTV Converter for this. As an SSTV caption machine (SSTV text generator really) it was perfect!
I used this converter for many years until I started using GSHPC SSTV system by DL4SAW, perhaps around 1995.