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Hack B/W portable television

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I need information about hacking a my B/W portable television to have esternal Audio/Video RCA jacks. How can I record my flights?? Can i hack a video recorder to 12V DC (i don´t have camcorder)?? Or it´s better to use an inveter (12V DC to 220V AC)?? It´s enough a 12V 7 Amps gel battery for the receiver, the TV and the video recorder?? Autonomy?? Thanks

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I need information about hacking a my B/W portable television to have esternal Audio/Video RCA jacks.

When I hacked my portable B/W TV for external A/V jacks, I used an O-scope to identify the circuitry where composite video appeared. Same for the audio. Then I cut the traces and wired in a DPDT switch and RCA jacks. The switch selects between normal operation and external A/V. This is not a project that could be done easily if you do not have a scope or some TV repair experience.

A photo of my portable TV can be seen here (as well as the PVC stand that has been cloned by a lot of folks): http://www.rc-cam.com/fldequip.htm

BTW, for those folks in the USA, there are cheap (less than $30) portable TV's that are readily available that already have the A/V feature. I have seen them at WalMart, Target, Walgreens, and other discount stores.

Can I hack a video recorder to 12V DC (I don´t have camcorder)?? Or is it better to use an inverter (12V DC to 220V AC)??

You will need a "true sinewave" output inverter. Avoid the low cost "modified sinewave" type.

It´s enough a 12V 7 AH gel battery for the receiver, the TV and the video recorder??

At least twice that capacity is needed. You can determine exactly what you need by measuring the current draw of the entire 12V setup. Then multiply the result by the number of hours you need (this will convert it to Amp Hours). I suggest you double the final value for best performance.

Keep in mind that GelCell batteries, like most lead acid cells, will be ruined if they are allowed to discharge too deeply. I suggest that you use a battery alarm to indicate when voltage falls below 12VDC.

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I have an osciloscope but i don´t know how to identify these signals. Could you give me more information about that?? Thanks

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Typical waveforms for the common video standards are found here: http://www.maxim-ic.com/appnotes.cfm/appno...ote_number/1184

Your profile does not say where you are from, but given the 220VAC mains, I would assume that you are in a country that uses PAL or SECAM video. In any event, be sure to observe the waveform voltage specs for your area.

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You will need a "true sinewave" output inverter. Avoid the low cost "modified sinewave" type.

I've been using a cheap square wave inverter for some time now with my VCR without ever having any problem. I think this is due to the fact that every VCR now has a switching power supply which really doesn't care about what's coming in. No interference either.

Regards,

Kilrah

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