05-03-2015, 07:07 PM
The latter ZX Spectrums were fitted with the TEA2000 video chip vice the earlier LM1881. Although a vast improvement on the earlier chip there were still some issues with colour burst though due to the chroma signal bleeding into the video output, and often the case different depending on the television in use. I've had the chance to test on four different screens (a 14" Sony Trinitron CRT, 14" Bush CRT, 21" JVC CRT and a modern Samsung 19" flatscreen) and the video quality would often be a case of pot luck.
There is a mod that filters out this nasty effect. Comprising of nothing more than a 15mh inductor and an 82pf ceramic capacitor the parts are wired in series between pins 8 and 17 of the TEA2000 chip, 17)---<82pf>---<15mh>---(8, the image improvement can range from subtle to good clarity, again screen dependant. Photo below shows the parts fitted over the top of the TEA2000 chip.
There is a mod that filters out this nasty effect. Comprising of nothing more than a 15mh inductor and an 82pf ceramic capacitor the parts are wired in series between pins 8 and 17 of the TEA2000 chip, 17)---<82pf>---<15mh>---(8, the image improvement can range from subtle to good clarity, again screen dependant. Photo below shows the parts fitted over the top of the TEA2000 chip.
