UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Ken · 5th Aug 2017, 7:10 pm

Hello Jay,
Built the little circuit this afternoon. I built it into the modulator box having disconnecting the appropriate parts. I left it so as the modulator could be returned to operation if I ever wanted it. There is enough room for this. However, the bad news is that I still don't see the cursor. I tried on two TVs. The first has an lcd. It did not change from the blue screen. I also tried the 5" B/W crt TV that I used before. It has a composite video input. The only changes with it was if I switched the ZX81 on then of. The screen looks the same whether the ZX81 is on or off so I think it must be the vla. I also tried the circuit without the diodes but got the same results. I suppose it rules out the modulator.

Regards,

Kwn.

5th Aug 2017, 7:10 pm	#54
Ken Hexode Join Date: Oct 2003 Location: Near Glasgow, UK. Posts: 309	Re: Sinclair ZX81 Hello Jay, Built the little circuit this afternoon. I built it into the modulator box having disconnecting the appropriate parts. I left it so as the modulator could be returned to operation if I ever wanted it. There is enough room for this. However, the bad news is that I still don't see the cursor. I tried on two TVs. The first has an lcd. It did not change from the blue screen. I also tried the 5" B/W crt TV that I used before. It has a composite video input. The only changes with it was if I switched the ZX81 on then of. The screen looks the same whether the ZX81 is on or off so I think it must be the vla. I also tried the circuit without the diodes but got the same results. I suppose it rules out the modulator. Regards, Kwn.