Starting Composite Mod

Discussions about Sinclair ZX80 and ZX81 Hardware
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gammaray
Posts: 586
Joined: Sun Apr 17, 2016 2:44 am
Location: Texas

Re: Starting Composite Mod

Post by gammaray » Mon Nov 19, 2018 5:31 pm

I would think the 50Hz signal would disrupt the signal to the US TV.

Elsewhere mentioned is the vertical hold to adjust down to 50Hz which newer TVs no longer have. Do they adjust automatically in US?

Trying my UK Zeddy but I cannot get any partial signal on my channel 33 or 36 even without bluescreen. Board needs testing and video mod and 60 Hz change I guess.
5-TS1000,UK ZX81<-Sheelagh, US ZX81, 2-TS1500/KDLX , 3-TS2040 printer, 2-TS2020 cassette decks, ZXPAND+AY, ZeddyNET, ZXBlast, UDG, ZX8CCB, AERCO, BUILDS/REPAIRS ZX Spectrum, ZX80 Minstrel, ZXMAX48 v1 v2, 2-TS-2068, ROM, 16kRAM

desiv
Posts: 27
Joined: Mon Oct 29, 2018 10:28 pm

Re: Starting Composite Mod

Post by desiv » Mon Nov 19, 2018 6:03 pm

gammaray wrote:I would think the 50Hz signal would disrupt the signal to the US TV.
Actually, not really a problem in this case.
Now, I am going into a monitor, not a TV, but it still wasn't a big deal.
My monitor has a vertical adjustment dial and all I had to do was adjust it a bit to stop it rolling.

I probably should try this guy on my actual TVs, but I really don't expect much with the basic mod anyway.
I'm waiting for another batch of CX8-CCBs for a cleaner upgrade.

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RS232
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Joined: Fri Apr 05, 2019 8:57 pm

Re: Starting Composite Mod

Post by RS232 » Mon Apr 08, 2019 12:58 am

Sorry for the late reply i just joined. I seem to remember reading adding two diodes will improve brightness to a composite mod on an zx81.

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