Digital TV Converter Hack

Learn how to mod/hack a DTV box to run on battery power! Now that the digital TV conversion is right around the corner, no one has put any thought into what happens to your old analog portable TV's since ALL of the DTV boxes are AC powered. What about camping? What about emergencies when you want to watch news/weather alerts and have NO power? Here's the solution.

Step 1 What You Need...

1). RCA DTA800B1 DTV box.
2). Radio Shack Barrier Strip or some other type of screw connector
3.) Radio Shack 12V Car Lighter Adapter if you want to use this in a vehicle.
OPTIONAL: Yuasa 12V Rechargeable Sealed Lead Acid Battery

Comments

[ElvenChild]

does your portable tv have A/V in?

[Weegee097]

Awesome! 5/5

[crfive_0]

This is awesome. Somebody PLEASE help me find an Instructable doing this exact same thing but to a LCD Computer Monitor??? I desperately need to run a monitor off 12v efficiently and i dont want to use a power inverter, Just like this tutorial, it would be pointless to turn DC to AC just so the component would then turn AC back to DC to run itself... HELP!

[static]

 I just pop the hood on a Digital Stream DTX 900 converter sold by Radio Shack.  This was purchase early on before analog pass through was mandated, I doubt this unit is still sold, and my discovery may not hold true with current Digital Stream Products YMMV. To my dismay the silk screen on the circuit board reads as follows. GND 5.5V GND3.3V GND. I well I do have a 75 W. inverter to use though that's overkill for a 7 W. load. Back to the drawing board on this project.

[Computothought]

Mine is the same. I can get an inverter for under 10 dollars. I might go that way. an lm3940, 7805, plus parts could fit on a board that could go inside to replace the existing ps board.

[static]

Yes; if the regulators can dissipate the heat that is an option to consider, that hadn't dawned on me at all. While the heat is wasteful, it may be less wasteful than using an off the shelf inverter to power the box. Where battery operation is inferred here, wasted power is a consideration.

[Steamdnt]

 IS that a 7805 by the PSU? if it is, It could be run on 5volts rather than 12 with its removal. 

[Yerboogieman]

So does a DTV box give you better reception also?

[ReCreate]

Erm..no?

[Yerboogieman]

You just ruined my wish of having good reception from an antenna.

[ReCreate]

You will keep the same reception

[Yerboogieman]

Kipkay's video is deceiving....

[ReCreate]

You mean misleading...right?

[Yerboogieman]

Yeah, i couldn't think of the word. Don't they mean the same, as on dictionary.com?

[static]

 deceiving, misleading how? The converter box operates on 12 VDC battery power, what was the entire point of this instructable. The only comment on signal reception was "the signal is great".

[Mr. Squishy]

Ugh, DTV boxes will give you better reception with any antenna. To get better reception, you can get a new DTV or HDTV antenna. You can also move your antenna outdoors.

[osgeld]

Its double sided, channels that come in are of course digital clear, but channels that dont come in well will pause, and break up so like in my case channel 8 (pbs) used to come in a little snowy but totally watchable, now with dtv i mostly get a black screen and every once in a while a screwed up still image will pop in to frame

[thebriguy]

Agreed w/Osgeld - and they don't seem to work when moving. Is the signal wave length incompatible with a moving tuner? I tried a portable TV w/ a built in digital tuner and a rigged set top dtv converter on my minivan's entertainment system and both work when stationary, but freak out/break up & freeze when moving.
Any suggestions regarding how to fix this problem.

I wanted another portable entertainment option for the kids and I'd love the weather radar station in my van so I can plan commutes better. Also, my wife dreams of doppler in her car - she's a weather freak (but I don't want to pay a monthly fee for a dedicated device (like used on boats/ships)

[The 4th Doctor]

This thing would easily run off of 12AA probably even AAA just thought i would mention that

[static]

 You would only need 8 or 10 to get 12 V., depending on what kind of batteries you are using.

[The 4th Doctor]

woops typo

[Kipkay]

Yes it would but not for very long at all.

[The 4th Doctor]

D cells should last it a good while what is this 30 watts, maybe 4 hours

[MACKattacksnipe]

im using banana plugs for power

[static]

 Banana plugs have the same drawback, that Kipkay's method has. A live wire to pop fuses.  A coaxial power connectors solve that problem, and many already have 12 VDC power cables terminated in a coaxial plug. Where Anderson power poles are becoming the standard in the emcomm world, I may use a power pole receptacle or re- purpose the AC power cord removing the AC plug for power pole connectors. Yes that would remove the AC power option. In the end   the simple solution is to buy a converors that use external 12VDC supplies, find them here www.ezdigitaltv.com/Additional_Features_Matrix.html

[welder guy]

hey kipkay im huge fan of your youtube videos and had a question, do you have ANY dtv box scematics. i cant find any on the web and would like to build a dtv circuit in a rs project box. i think the dtv boxes are so big is because they want it to fit on top of your tv. what about handheld tv's. plus i could make it battery powerd

[static]

 While YMMV, but it only costs time to try use this www.fcc.gov/oet/ea/fccid/  to look up the FCC ID number of an existing converter box, often the searches lead to schematics. In that the converter circuits use embedded computers/software, I really doubt any chances of success of trying to use any schematics of  a commercial product found or the ability to decrease the size much at all. Pause the video. Even if you removed the power supply section the RF modulator area looks to take up 25-40% of the remaining area. Simply removing the power supply dection of this RCA and modifying the cabinent accordingly would make it much more compact at  a much less cost, but of course you would loss the AC operability option.

[geeklord]

Wow, that is the exact same box that my family has! One broke so I got it. The sound stopped working on it, but the picture was fine. The other box that we got does the opposite; the sound works but not the picture. It only does this every once in a while, but the other one's problem seemed to be permanent. The power supplies in them are nice, mine was rated up to 1 amp. Anyone have an idea why the one broke, and why mine had a 4 pin power supply connector?

[ironsmiter]

almost certainly +12V ground ground +5V. Check to see if two of the pins are physically connected by traces. those will be your grounds. Not being connected doesn't mean they AREN'T ground... just that the designers prefered isolated, discreet grouds for their power lines. As to why they fail to output video or sound... I'd first suspect the physical rca connectors. Check for cold-solder joints, or just loose connectors. Unless it also fails to output over coax, in which case, good luck. That's probably much more complex fried circuitry.

[geeklord]

The connector is 12v GND GND 12v. I'm absolutely certain about that one. Thanks for the thoughts on why it broke.

[Last_Liberal]

What are you using for an antenna?

[Kipkay]

I used a standard VHF/UHF/FM backup antenna I have in my attic. I believe when the switcheroo occurs in June you will need an HD antenna. You can get those at RS or online. Around $30.

[biggybilly]

Dear Kipkay, Re. your RCA DTV , I had already bought a Magnavox-Funai tuner model TB100MG9, and can't locate a 12v DC power supply output, it appears it might have more than one operating voltage as there are 2 sets of 4 diodes and what looks like a transformer with multple secondaries, and I'm scared to randomly poke around with my VOM. Can youAssist me?

[ironsmiter]

your power supply circuit probably has at least 5 volt, 12 volt, and grounds. possibly a 3.3 volt also. Best bet is, relegate that box to normal tv usage. Go and get another box, from a different manufacturer, and try again. If you get one that uses a 5volt input. DTVPal is one such box. You can then hack a simple cellphone charger for the 12V(12-16 automotive voltage) to 5 volt converter circuit. Then, you don't even need to open the box. just put the circuit board into a project box, and wire it to the necessary connectors.

[Mr. Squishy]

You don't need an HD antenna. It said that on http://dtv.gov

[osgeld]

i have these things too, and as far as i understand you can use your normal antenna's after the full switch, but it may need an amplifier

[welder guy]

amps do nothing. you cant get what your antenna cant recive.

[static]

Osgeld said simply  " you may need an amplifier", and that's certainly true as far as it goes, no need to confuse the issue by implying something was said that wasn't. Amps do DO something. They can increase a weak signal received by the antenna to a level that's usable by the receiving equipment. Given the all or nothing nature of digital, combined with station that where formerly on VHF switched to UHF and many VHF and UHF transmitters required to reduce power at the change over, chances are we will be seeing amps employed more than ever for those who have to rely on broadcast TV.

[osgeld]

wellllllllllll when we moved out of the downtown area we could not pick up any channels, getting a +26db amplified antenna and we get most channels so it did not do nothing, infact it made a dramatic difference from jack squat to almost back to normal

[static]

 LOL! Well of course amplifiers have been alway been an important part of total systems I suspect welder guy was being lazy with the pat response, that "sounded good" or not very experienced in this area. Glad too read you found a solution that's working for you. I haven't turn on my TV, since I turned it one after te switch in Feb. to find that I was too far away. Before the snow flies I hope to get a better antenna AND amplifier installed installed.