low_budget Posted June 24, 2013 Author Share Posted June 24, 2013 (edited) The FCC does RF interference testing (in the USA anyway.) Testing to ensure the electronics both A: do not emit RF interference and B: are not susceptible to RF interference. The large steel shielding present on retail video game systems and electronics is required by FCC regulations, it isn't needed for good quality picture. I've never seen any difference in picture from removing this shielding from a game console, except in the Vectrex where high voltages are present. Any testing Nintendo would do is to ensure their electronics pass and are therefore legal to sell. Naturally there would be quality control testing by Nintendo to ensure good picture with the available TVs at the time, but this would be probably be done before the FCC testing. Nintendo released a variety of NES PCB revisions with the picture quality varying considerably over the years. The front loader has generally good composite video and RF. The 1993 Nintendo NES top loader has bad jail bars, so Nintendo must have rushed quality testing on these PCBs. It is only the rare PCB redesign of these systems that don't have jail bars. (and the AV famicom.) The RGB PPU used in the Nintendo arcade systems inherently has some jail bars, but I think this is due to the chip never being designed for high resolution displays. When played on a CRT monitor the picture is perfect. The jailbars here cannot be eliminated entirely, only covered up. I've seen many solutions trying to fix this and they either don't help or have negligible improvement. I don't think solutions I've read like covering a PPU chip in copper foil would offer any improvement, I have lots of ground plane coverage under the PPU that accomplish the same thing. I will do a re-test with my GBS-8200 VGA converter, as this seemed to amplify any jailbar presence. The s-video converter didn't show any jailbars. RF interference is only an issue if the PCB design is really bad (like the vectrex.) The major cause of bad jailbars are PCB traces that cross important video signals and/or poor grounding. That's why the NES top loader looks like crap compared to other NES systems. The issues with the RGB picture quality on the Super 8 that I thought were issues were instead caused by the Powerpak. The composite PPU from a NES is very sensitive to timing (clock signal and data), but the RGB PPU is not. In the process of designing the Super 8, I've analyzed different NES, Famicom, and arcade PCBs and schematics and compared the picture of each. I'm on my 4th revision of the NES Super 8 and the picture has kept getting better with each version, so I must be doing something right, LOL. Edited June 24, 2013 by low_budget 2 Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.