interference filled Famicom picture

I've owned this standard model Famicom for two years and I have never been able to receive a clear RF picture with it. I'm adhering to all of the "using a FC on an American TV" rules. I have an American RF switch, I've used both channels 95 and 96, I have a JPN power supply.


The picture 96% of the time is wavy and is filled with light static. Like a radio...if I move close to the console is relieves the interference temporarily...but when I pull away it returns. Do some units ultimately end up this way. What can I do?

You can AV mod it, try more channels (I've had FC that come in on chans 4-13) or I guess try tweaking the RF modulator for another frequency.

Oh and what kind of RF switch do you have?

Kyuusaku said:

You can AV mod it, try more channels (I've had FC that come in on chans 4-13) or I guess try tweaking the RF modulator for another frequency.

Oh and what kind of RF switch do you have?

Click to expand...

I can't do mods and don't plan on modding it for AV. I'm using a standard first party NES RF switch. My body's proximity affects the level of interference...very strange.

I guess some wire in the FC is acting as an antenna and picking up RF, and you moving in closer is acting as shielding. As far as you can tell the game is working underneath the interference? Something is probably up with the RF modulator.

NES RF switches are suitable so that couldn't be it.

Kyuusaku said:

I guess some wire in the FC is acting as an antenna and picking up RF, and you moving in closer is acting as shielding. As far as you can tell the game is working underneath the interference? Something is probably up with the RF modulator.

NES RF switches are suitable so that couldn't be it.

Click to expand...

Yes, the game works fine. If I hover over the console the interference stops periodically. I've used the system on a number of TVs with the same results so I don't think it's the modulator. If I plug that same RF switch into my top loader NES the picture is clear as day.

If it always has the same results it has to be the modulator. RF modulator =/= RF switch. The modulator is an analog circuit inside the FC on the power board that mixes audio and composite video with a tuned RF signal (channel base frequency) to shift the low frequency A/V (0-6 MHz) to a high frequency TV channel (90-96 MHz for Japanese channel 1). The RF switch is an external device which blocks radio signals from the antenna input once the console is powered on which would otherwise interfere with the game. Sometimes like in the Neo Geo home system's case the RF switch is combined with the modulator into one device, but they are different things.

After thinking about it, it actually could still be the RF switch. Probably the reason the NES switch works for me is because my RF modulator has been tuned to approximately US channel 4 and the switch is designed to block channels 3-4 since those are commonly used by equipment. If someone in your area is broadcasting at the frequency your RF modulator is tuned to, and the RF switch can't block it since it falls out of its range, you will get lots of interference.

Kyuusaku said:

If it always has the same results it has to be the modulator. RF modulator =/= RF switch. The modulator is an analog circuit inside the FC on the power board that mixes audio and composite video with a tuned RF signal (channel base frequency) to shift the low frequency A/V (0-6 MHz) to a high frequency TV channel (90-96 MHz for Japanese channel 1). The RF switch is an external device which blocks radio signals from the antenna input once the console is powered on which would otherwise interfere with the game. Sometimes like in the Neo Geo home system's case the RF switch is combined with the modulator into one device, but they are different things.

Click to expand...

I'm really ignorant when it comes to tech terms, thanks for clearing that up. So does modulator replacement/repair exist? What are my choices.

Lol.. It's RF, of course it's going to have a shitload of interference.

Since you're too lazy to modify it to output a composite signal, I can only suggest using it on a CRT as the lower resolution should make the interference far less noticable.

Hewitson said:

Lol.. It's RF, of course it's going to have a shitload of interference.

Since you're too lazy to modify it to output a composite signal, I can only suggest using it on a CRT as the lower resolution should make the interference far less noticable.

Click to expand...

Fuck off. It's not receiving standard RF interference. There is something wrong with the picture beyond standard shitty RF quality. I'm not modding it because I'm inept/uninterested in learning/risking fucking up the system.

I'm using it on a CRT also.

You can:

- disconnect the antenna/CATV coax if you have one going into the RF switch lol
- A/V mod the FC, but IMO this will uglify your console if you don't remove the RF stuff and reuse the existing holes in the plastic.. Probably a little complicated. 99% of the modders out there have no problem mutilating beautiful consoles so I wouldn't send my FC to one of them either.
- retune the RF modulator, I think this might be as simple as turning a variable capacitor
- try one of those RCA -> F connector adapter things on eBay for pre-FC consoles without automatic RF switches, it will allow you to bypass the RF switch, but I'm not sure it will get you any closer to success

You obviously have absolutely no idea just how succeptible to interference an RF signal is.

If you're not willing to put the necessary work in to fix the problem, don't bother complaining about it.

Kyuusaku: Putting a couple of AV jacks on the rear of a console doesn't detract from the looks of it at all if done neatly. At least in my opinion.

Hewitson said:

You obviously have absolutely no idea just how succeptible to interference an RF signal is.

If you're not willing to put the necessary work in to fix the problem, don't bother complaining about it.

Kyuusaku: Putting a couple of AV jacks on the rear of a console doesn't detract from the looks of it at all if done neatly. At least in my opinion.

Click to expand...

It's not a matter of work ethic. I'm not handy...I have no interest in learning how to do mods.

I figured if I put my complaint in the complaint center, I could get a little insight as to how a tech-ignorant bumpkin like me can isolate the problem, and find the proper course of action in order to rectify that problem.

Thank you Kyuusaku for the help.

This is why I got an AV Famicom. I just can't deal with RF anymore, although I lose out on that more classic look of the console. All the same, I can appreciate where andsuch is coming from and kyuusaku's suggestions are an interesting read.

I fail to understand why you would not want to educate yourself in this area in order to get a better result from your eqiupment.

Anyway, I think the suggestion of attempting to retune the RF modulator is the best and simplest one to start off with. Usually the top is held on by a few metal tabs. I reckon you might be copping some interference from a local FM station.

Hewitson said:

I fail to understand why you would not want to educate yourself in this area in order to get a better result from your eqiupment.

Anyway, I think the suggestion of attempting to retune the RF modulator is the best and simplest one to start off with. Usually the top is held on by a few metal tabs. I reckon you might be copping some interference from a local FM station.

Click to expand...

Would a snap-over ferrite core help?

http://www.dataq.com/products/hardware/accessories/fc.htm

I had one of those come on an RF cable in a bunch of stuff I brought a few years ago, never dawned on me until now it could have been to reduce intereference.

Never used the cable though so no idea how well it would work.

Guess it depends if the RF cable of the FC itself is getting the intereferenc

You can always put the console in a brass cage.

jew90 said:

Would a snap-over ferrite core help?

http://www.dataq.com/products/hardware/accessories/fc.htm

I had one of those come on an RF cable in a bunch of stuff I brought a few years ago, never dawned on me until now it could have been to reduce intereference.

Never used the cable though so no idea how well it would work.

Guess it depends if the RF cable of the FC itself is getting the intereferenc

Click to expand...

I've tried one. It didn't do anything.

Like Kyuusaku said, buy a F to RCA adapter. Best way to hook up something with RF. Its how I hooked up my Atari 2600 Jr.