View Full Version : Adding Composite/component/s-video inputs?


RCAZenith
05-10-2016, 09:14 AM
What would it take to add an input to a tv that did not come with said input? I have seen a YouTube video of a 70s RCA XL-100 table top with component jacks hacked into it. Has anybody undertaken such a project?


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andy
05-10-2016, 11:19 AM
It depends on the set. Hot or cold chassis makes a big difference. Later solid state sets may have be able to accept composite directly at the right point. Tube sets will probably need a voltage and polarity matching circuit.

Electronic M
05-10-2016, 01:22 PM
Some tube sets will take a composite signal easily. Most Zenith and RCA tube color sets will take it decently after the detector.

Arcanine
05-10-2016, 03:10 PM
Some tube sets will take a composite signal easily. Most Zenith and RCA tube color sets will take it decently after the detector.

A signal amplifier would do a lot of good. While tube sets will gladly accept composite inputs after the detector, there is not enough drive on the signal line for a bright picture. It will appear very dark and some images will be quite washed out.

Also Tube sets have no rejection circuits like solid state sets, and will display copy protection, which will also effect how things are viewed. Some copy protection is quite violent and will mess with the contrast, dimming and brightening it, which on a tube set with no amplifier makes it unwatchable.

Some very early solid state sets also display the copy protection. For instance, The first 5" Sony Trinitron portable set from 1972, a KV5000, will display copy protection and has issues with it. The replacement for the KV5000, the 1976 KV5100, has no issues and can reject copy protection and displays a perfect, flawless image.

RCAZenith
05-11-2016, 08:32 AM
A signal amplifier would do a lot of good. While tube sets will gladly accept composite inputs after the detector, there is not enough drive on the signal line for a bright picture. It will appear very dark and some images will be quite washed out.

Also Tube sets have no rejection circuits like solid state sets, and will display copy protection, which will also effect how things are viewed. Some copy protection is quite violent and will mess with the contrast, dimming and brightening it, which on a tube set with no amplifier makes it unwatchable.

Some very early solid state sets also display the copy protection. For instance, The first 5" Sony Trinitron portable set from 1972, a KV5000, will display copy protection and has issues with it. The replacement for the KV5000, the 1976 KV5100, has no issues and can reject copy protection and displays a perfect, flawless image.



I am definitely talking about solid state sets. Would a component-ready set take S-video relatively easily?

Also, how would you access an "auxiliary" channel if there was not one on the tv's tuner or jungle ic?

Kamakiri
05-11-2016, 08:35 AM
Why not just hook up an RF modulator?

RCAZenith
05-11-2016, 11:13 AM
Why not just hook up an RF modulator?



It's doable, but every conversion means a loss in quality. Plus video game systems can have terrible RF output

Arcanine
05-11-2016, 12:47 PM
It's doable, but every conversion means a loss in quality. Plus video game systems can have terrible RF output

He's talking about one of those RF Modulators with RCA inputs. I have a radio shack one and it is extremely high quality. It even can do stereo sound for TV's that accept stereo.

A good quality one, you will not be able to tell the difference that it's RF. The quality is simply that good.

Mine is a model 15-2525, I couldn't find it on ebay, but it's the best money can buy so it's a little rare. I got really lucky and found it for a dollar at goodwill.

Kamakiri
05-11-2016, 03:50 PM
Seems like a heck of a lot less effort to me....

msimendi
05-11-2016, 07:19 PM
Supposedly you get a better picture. On Phil Nelson's website he shows a side by side comparison of a test pattern using composite and RF:

http://antiqueradio.org/A-V_AdapterForVintageTVs.htm

RCAZenith
05-12-2016, 08:16 AM
Supposedly you get a better picture. On Phil Nelson's website he shows a side by side comparison of a test pattern using composite and RF:



http://antiqueradio.org/A-V_AdapterForVintageTVs.htm



That's the point. We all know the older sets are as good as and mabye better than the later BPC sets in terms of quality, but not having AV really handicaps them. I have an 80s low line Zenith that I would love to hack a mono AV into. It would really make a good picture if it had a fresh CRT and RCA inputs.

Outland
05-14-2016, 03:32 AM
You can also use a VCR. VCRs usually have better than normal modulators and will give the best picture RF can deliver. For higher quality, you would have to put in a composite connection and some tubes simply won't be able to accept the signal.

Also they're cheaper.

It'd be hard to convince that old tubes without even composite on the chassis had a better image than a set with composite inputs. The tubes were designed with the chosen input in mind unless they were shared.

wa2ise
05-14-2016, 08:48 AM
In theory, S-video would give the best picture, if you can figure out where it inject it. You'd have to find in the set where the separated luma and chroma signals are, what voltage amplitudes and polarity you'd need, and delay between the luma and chroma is needed (maybe zero).