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Re: If you like your submarine simulations fast, arcadey,...

Posted: Wed Mar 28, 2018 8:23 pm
by Andy Rea
I have seen similar effect a while back when tinkering with another idea.

that was a noisy clock signal on the edge connector that woudl upset the line counter , the small capacitor to the left of the chip on the UDG board is supposed to take care of noisy clock signal.

Could i be really cheeky and ask do you have good soldering skill ?

the 0 ohm link (looks like a regulator smd resistor with a 0 on it ) to the left of that capacitor could be changed to say 330 ohm that and the capacitor would then form a classic RC filter.

as for the faint vertical lines i don't know, are they still present without the UDG board connected ?

regards Andy

Re: If you like your submarine simulations fast, arcadey,...

Posted: Wed Mar 28, 2018 9:49 pm
by schombi
I do have some basic soldering skills, but I´m far away from being good. I can replace a transistor or do a composite mod, maybe replace a faulty chip, but that´s about it.

I´ll do some more testing as time allows and I will try to get one of my other Zeddys tested with the UDG4ZXpand and the ZXPand+ (using the TV signal).

Re: If you like your submarine simulations fast, arcadey,...

Posted: Wed Mar 28, 2018 9:54 pm
by Andy Rea
okay that would be great,

if everything fails i have no problem sending you a new board.

Regards Andy

Re: If you like your submarine simulations fast, arcadey,...

Posted: Wed Mar 28, 2018 10:05 pm
by nollkolltroll
I had the same problem with both my udg boards. On 3 different zx81s, but sorted as soon as I changed power supply. I guess the first psu was nosiy.

Re: If you like your submarine simulations fast, arcadey,...

Posted: Wed Mar 28, 2018 10:56 pm
by Andy Rea
nollkolltroll wrote:
Wed Mar 28, 2018 10:05 pm
I had the same problem with both my udg boards. On 3 different zx81s, but sorted as soon as I changed power supply. I guess the first psu was nosiy.
hmmm thanks for the input, i think maybe it is down to noise, maybe this is a hazard for low power devices more suceptible to noise ?

Andy

Re: If you like your submarine simulations fast, arcadey,...

Posted: Thu Mar 29, 2018 6:40 am
by schombi
I´ll try that out as well as get back to you. Thanks for your suggestions and your offer, Andy.

Re: If you like your submarine simulations fast, arcadey,...

Posted: Thu Mar 29, 2018 7:45 am
by nollkolltroll
Oh, and both were switching PSUs with voltage settings. It did not matter what voltage was set, 7/9/11V yielded the same results on both. I haven't looked at the troublesome PSU in a scope, but it might be time for that.

Re: If you like your submarine simulations fast, arcadey,...

Posted: Thu Mar 29, 2018 12:50 pm
by Moggy
Just to give the other side of the coin my UDG board is still plodding along happily regardless of power supply used and as mine was an early evaluation one is it possible the production ones sold on SMR used different components to mine?

Kudos also Andy for the offer to Schombi, the fair-mindedness shown to and by everyone is one of the many things I like about the members on this forum. :D

Re: If you like your submarine simulations fast, arcadey,...

Posted: Thu Mar 29, 2018 3:34 pm
by Andy Rea
Moggy wrote:
Thu Mar 29, 2018 12:50 pm
Just to give the other side of the coin my UDG board is still plodding along happily regardless of power supply used and as mine was an early evaluation one is it possible the production ones sold on SMR used different components to mine?

Kudos also Andy for the offer to Schombi, the fair-mindedness shown to and by everyone is one of the many things I like about the members on this forum. :D
You have a green board now don't you? Same as all the others. The older purple board was same components just a prototype PCB before ordering PCBs in bulk.

Regards Andy

Re: If you like your submarine simulations fast, arcadey,...

Posted: Thu Mar 29, 2018 8:37 pm
by Moggy
Yes Andy it's a green one.