Fuzzy Picture Question

[BetwixtThieves]

 

I have a Famicom system that I am hooking up to an old tube TV through the RF connector. The system works fine other than the picture can get pretty fuzzy (more so than my other older consoles that use RF).

I have found that if I move myself I can change the quality of the picture - even to the point that I can get an almost crystal clear picture. For example if I rest my leg near the console it will become crystal clear and as soon as I back away it can get wildly fuzzy/snowy.

Any thoughts on if this is an RF shielding issue, too much interference in my game room, a capacitor/adjustment issues in the console? Any thoughts or help would be appreciated. I'm not looking to do an AV mod, I'm just curious if there is something I can do to help with this issue that keeps the system operating through RF.

Thanks! 

[BetwixtThieves]

I think my issue is the cable coming from the RF switch to the RF jack of the TV. I was able to jam the plug that goes into the TV up against the wall and something about the wall's resistance or closeness makes the signal come in perfect. No more artifacts, fuzzy/snowy picture issue.

I'm tempted to make my own adapter with some electrical tape and splicing some cables together, but I'm out of R6 cable right now and I'm too lazy to go buy some.

[emerson]

Sounds to me like the ground shielding in the coax somehow isn't grounded anymore. Have you performed continuity tests?

I would try cutting the coax end off and replacing it with a thread on connector like the one below. These can be found in most big box stores and online. Be sure that the cable you have is in fact RG6 and not RG59.

https://www.walmart.com/ip/onn-RG6-Coax-Twist-On-F-Type-Connectors-2-Pack-Jasco-Products-100008638/195189786?wmlspartner=wlpa&selectedSellerId=0&wl13=5387&adid=22222222278195189786_117755028669_12420145346&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=m&wl3=501107745824&wl4=pla-293946777986&wl5=9015254&wl6=&wl7=&wl8=&wl9=pla&wl10=8175035&wl11=local&wl12=195189786&wl13=5387&veh=sem_LIA&gclid=EAIaIQobChMI2OWansq09gIVsxitBh1_KQGaEAkYAyABEgJNXvD_BwE&gclsrc=aw.ds

[BetwixtThieves]

@Emerson - thanks for the response!

I am going to look into that today - need to buy some R6 cable.

I'm not skilled enough to know what I would need to do to perform a continuity test. I created a make shift cable with R-59/U because it was all I had lying around and it looked like garbage. I also tried using a NES cable and that looked bad too.

I'm using it with my weird rigged up setup for now, but I'll try this so that I'm not jamming the cord into the wall forever.

[emerson]

So you rigged it with RG59 and the picture looked bad?

As you likely know RG6 and RG59 are both 75ohm coax. Unless your mod is somehow wonky this could suggest the problem lies elsewhere, possibly the coax input of the tv?

I am unsure if an NES rf unit works on the Famicom or not. My gut instinct says no since the NES uses channels 3-4 where the Famicom uses channels 95-96. I suspect a band pass filter exists in the NES rf adapter but that's a guess. I can test with my twin later and find out.

How much RG6 do you need? I might be able to help with that.

[BetwixtThieves]

@emerson - you are too kind.

So I have been playing around with this today and found the following. My NES units do not look good using RF on this TV. Very fuzzy/snowy. Worse than the Famicom. I normally run them composite. My Atari 2600 looks good though - almost flawless.

I brought a second TV in the room and tried out the systems. The Famicom wouldn't work on it because it couldn't get channel 95 or 96, but the NES looked grainy like the Famicom does on the second tv. 

I hooked back up my Famicom to the original TV and played around some more. I can get an almost crystal clear picture if I rest my body near the unit, and then by accident I discovered that if my daughter enters the room and stands behind me the picture becomes Perfect. If she leaves it gets a little fuzzy and if I move away from my Famicom it gets quite fuzzy/snowy.

I'm guessing this is some sort of wireless signal (radio, internet, etc...) running through my office and our bodies are dissipating or absorbing some of that signal and protecting the RF integrity of the Famicom. This is just a guess though.

[emerson]

I went to test this morning and found the twin does not have rf output. Whoops...

In regards to moving around the room having an effect on the picture quality, I used to have a clock radio in my bathroom that would do the exact same thing. The volume and clarity of the station would drastically change depending on where in the room you were standing. The radio internally wrapped a length of wire around the line cord to use it as the antenna.

Hopefully the thread on f-type connector fixes the issue.

[P]

I am unsure if an NES rf unit works on the Famicom or not. My gut instinct says no since the NES uses channels 3-4 where the Famicom uses channels 95-96. I suspect a band pass filter exists in the NES rf adapter but that's a guess. I can test with my twin later and find out.

I'm quite sure it does work. People with NTSC NES says that their RF-switch works with the Famicom and I know people in Sweden that has got a picture in color but no sound (this is fixed using an FM radio though) with a PAL TV and supposedly the PAL RF-switch.

[emerson]

I'm quite sure it does work. People with NTSC NES says that their RF-switch works with the Famicom and I know people in Sweden that has got a picture in color but no sound (this is fixed using an FM radio though) with a PAL TV and supposedly the PAL RF-switch.

Good to know, I'll try and remember this. Thanks P!