Cable TV coax coming from wall, going into VCR, then into TV.
Audio going from VCR’s RCA outputs to Stereo Amplifier.
DVD player has RCA outputs (plus some fiber optics, S-video, and component video plugs I’d only be able to use in a video studio setup). Audio going to Stereo Amplifier. Works fine. Video going to … ?
Here’s the problem. I used to have a TV with its own RCA inputs, so I plugged the DVD video straight into that. Now I have a TV that ONLY has a coax input.
Figured I’d put the DVD through the VCR’s RCA inputs and then out through the coax to the TV along with the cable tv channels. But I forgot about the anti-copying crap. So the picture does the whole dimming-brightening-dimming thing.
Then I thought, A-ha! I’ll just buy an Atari-style game/antenna switch, which basically lets you switch between a coax-input antenna/cable TV audio/video signal and a second RCA-input video signal (typically the video game), then route either one out through a common coax output to the TV.
Lovely. Except it doesn’t work. The “game” position (the RCA input) gives me nothing but static.
Any suggestions? I assume I’m missing something to do with the ohms of the inputs, etc. Is it possible to do what I’m trying to do?
It wouldn’t work. The RCA input of the game switch is for an RF signal on channel 3 or 4, not a baseband video signal. What you need is an RF modulator, with takes the baseband video (and audio, should you wish) and converts it to a channel 3 or 4 output, which you can then feed to the cable/antenna input on the TV. These are available in electronics stores for $10-$20.
That sounds like a pretty old TV. AV inputs have been standard on most TV’s for over 10-15 years now. I’d put the 25 bucks of RF mod money toward a new TV instead. TV’s are prettty inexpensive these days, even fior larger 19 & 27" units
BTW if it’s not an old TV you might want to check the front for hidden push-release panels that flip down. Sometimes the AV connectors on some TV’s are hidden behind liittle panel doors on the front .
Believe it or not, I actually own an RF modulator. The TV is my sister’s (I’m squatting in her country house), and they used to use the RF modulator to plug their playstation into the TV.
The problem is, the RF modulator (though it has the channel 3/4 selector on it) only has a coax output. So I have the same problem: Coax VCR connection and coax DVD connection to a single coax TV input. I still need a switch to choose between DVD and VCR signals. Thought the game connector might have done it, but no dice, it seems. Coaxial a/b switch, anyone?
Crap! I was looking for that very product in Radio Shack but couldn’t find one … which is why I went for the game switch. Thanks all. Guess I’ll go shopping again.
No, that’s a UHF/VHF splitter/combiner. It has a pair of bandpass filters, one which passes VHF (channels 2 through 13) and the other passes UHF (broadcast channels 14 and up). It’s meant for use with separate UHF and VHF antennas, and has a DC pass for line-powered signal amplifiers. The DC pass is simply a high-value inductor that acts as a low-pass filter that allows DC to get around teh VHF bandpass filter. The OP could use a standard splitter/combiner, as long as only one device would be on at the same time, or each one was set to a different channel. He could se the RF modulator for channel 3 and the VCR to ouput on channel 4, for instance.
Here’s what you do: you set the VCR to output to channel 3, and you set the RF modulator to output to channel 4, and then you go get a good quality (don’t buy the cheapest one at radio shack, buy the mid-grade one if they have 3, and the best one if they only have 2) two-way splitter. You then turn it around backwards and it becomes a combiner. You’ll have a coax cable coming from the VCR that only carries channel 3, you’ll have a coax cable coming from the modulator that only carries channel 4, and if you plug them into the two “out” legs of the splitter, the “in” leg of the splitter will carry both channels 3 and 4.
A “splitter” is really a “splitter or combiner”, depending on which way you use it. I think the only reason they don’t sell them that way is that it would confuse people. Most people don’t need to combine signals, and when you combine signals, you have to be careful that you aren’t combining two signals that both have stuff on the same channel, otherwise the output will be garbage on that channel.
The coax A/B switch will work fine, but combining the signals gives you the luxury of just switching the channel on the TV to select the source. If you get a more expensive RF modulator, it will let you pick any channel to modulate on, rather than just 3 or 4, and that lets you build a whole lineup of inputs that you select by changing the channel on the TV.
If you plug your dvd player into the input rca jacks then plug the vcr in to your tv, thats all you need to do. Just keep in mind though that when you want to whatch your dvd, your vcr needs to be on and turned the the auxillary chanel not chanel three.
While technically this WILL work, you don’t want to do it. Modern DVD players have anti-bootlegging technology that notices when you do this, and can cause a number of things to happen to the picture. Usually it makes the picture slowly fade in and out of brightness. I’ve seen a few DVD’s at a friend’s place who had to do this because of a broken input on a TV, it’s not to bad to have to live through, but if you have the money to buy a switcher, then do it. I’ve even heard of some DVD players that won’t let you even watch it if you do this, by making many horizontal lines appear or seriously scambling the picture, but I’ve just heard that, so it may not be true.
Really the only analog antipirating protection DVD players use is called Macrovision, which does what you said to the picture. It works by confusing the AGC (automatic gain control) circuit that all modern VCRs incorporate. Some VCRs will bypass the AGC from AV In to AV Out, and so don’t suffer the problem mentioned, but none will properly record a Macrovision-encoded recording.
