mbarszcz-pcb / c64-rf-modulator-replacement Goto Github PK

It looks like R4 and R5 have been swapped in the photo here:

https://github.com/mbarszcz-pcb/c64-rf-modulator-replacement/blob/master/images/photos/c64-rf-modulator-photo-inst.png

I was using the photo as a reference when assembling and it had me confused for a bit :)

Hi, in the bom list, i see in the decription there's needed 150 Ohm 3/4W Resistors for R8,R11,R12...
Sure they are 3/4W or is a mistake?

Kindly regards!

Hi, I'm helping a guy on facebook regarding ground on long boards. He noticed that the GND is not mentioned in the readme (under jumper settings). I'm just presuming from the schematics, that the G.PAL jumper on the mother board must be joined/solder-blobbed for it to work ?
Looks neat btw !! :)

Hi!

Tried to upload your rev.D gerber files to PCBWay, and I got feedback that the files was not in the right format. Rev. C uploads and reviews fine.

Error message: "We need gerber file in fomat of RS-274x;"

Not really an issue but making you aware that UK PAL 250407 boards have floating ground pin to the modulator. So your modulator replacement actually requires the solder jumper on the board to be connected to make the ground good, or it will be loaded with interference. Might be worth adding a note about this to the readme.

https://youtu.be/jXSQe5f-Rsk?t=428

I made a video on this while i was installing the modulator replacement (the bad ram and other fails on the computer are not related this ground problem)

Hi, thanks for your project. I was wondering if this circuit could work in the Commodore 16, too. I am asking because I would like to integrate it in a clone mainboard I am making (with the obvious modifications for power, input signals, etc).

Here are the schematics of the C16/Plus4 modulator, taken from the Service Manual:

Your schematics look similar but not exactly the same. Do you think I could have a go with your circuit, which is a bit simpler and more tailorable (I like the pots!) or should I use the exact circuit from the above?

Thanks for your time! :)

I assume the schematic is ok, but
https://github.com/mbarszcz-pcb/c64-rf-modulator-replacement/blob/master/images/photos/c64-rf-modulator-photo-inst.png
the components on position R4 and R5 switched places?
68 ohms and 220 ohms.
Swapping the components doesnt match with "r4+rv1 approx 68-150" since it starts with 220?

But of course (r4/rv1) and (r5) are a voltage divider and the chroma-out level is still perfectly manageble.

Cheers!