16-08-2018, 09:18 AM
Peter, I wonder if some of the parts for your crosshatch came from the spares box at HP
I built my crosshatch generator c1974, when I first got an ex-rental colour TV. I think the design was in either WW or PTV and was even simpler than either David's or Peter's. It took H and V sync from the TV and gave a video output which I injected into the TV. Cobbled together on a bit of Veroboard. All very easy with a Thorn 2000. Power was probably a 4.5V battery.
My 2nd crosshatch generator was a lot more sophisticated. I was working at BBC Research Labs, between school and uni. Somebody had replicated a Labgear crosshatch and colour bar generator PCB and had a batch made in the PCB shop. I acquired one and built it up. Used a TBA520(?) as the modulator. I think I still have it, including the nice white painted case that was put through the BBC workshops as an unofficial job. Known as a "home office job" at the time.
Other "home office" projects of that time include a TV line selector (based on a PTV design) and an EHT probe. I still have both in regular use.
I built my crosshatch generator c1974, when I first got an ex-rental colour TV. I think the design was in either WW or PTV and was even simpler than either David's or Peter's. It took H and V sync from the TV and gave a video output which I injected into the TV. Cobbled together on a bit of Veroboard. All very easy with a Thorn 2000. Power was probably a 4.5V battery.
My 2nd crosshatch generator was a lot more sophisticated. I was working at BBC Research Labs, between school and uni. Somebody had replicated a Labgear crosshatch and colour bar generator PCB and had a batch made in the PCB shop. I acquired one and built it up. Used a TBA520(?) as the modulator. I think I still have it, including the nice white painted case that was put through the BBC workshops as an unofficial job. Known as a "home office job" at the time.
Other "home office" projects of that time include a TV line selector (based on a PTV design) and an EHT probe. I still have both in regular use.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
