What to do with old 5 portable UHF/VHF TV?

  • Thread starter Thread starter WarInTheHead
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Discussion Overview

The discussion revolves around the potential uses and modifications for an old 5" portable UHF/VHF television, particularly in the context of its functionality after the transition to digital broadcasting. Participants explore various ideas for repurposing the device, including technical modifications and preservation as a collectible.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant suggests that the lack of picture may be due to the transition to digital broadcasting, questioning whether the TV can still receive signals.
  • Another participant proposes using an old TV antenna and flat (300 ohm) antenna cable to potentially receive a picture, emphasizing the educational value of studying the TV's schematic diagrams and operation.
  • A different viewpoint mentions the possibility of the TV becoming a museum piece in the future, highlighting its historical significance.
  • One participant recommends looking for a digital converter box to connect to an antenna, noting that these are commonly available at thrift stores and junk shops.
  • Instructions are provided for building a folded dipole antenna, including materials and dimensions, which could be used to improve reception for the old TV.
  • Another participant mentions the availability of repair manuals and resources for further understanding the device's workings.

Areas of Agreement / Disagreement

Participants express a mix of ideas regarding the TV's functionality and potential uses, with no consensus on the best approach to repurpose or modify the device. Some advocate for preservation, while others focus on practical modifications.

Contextual Notes

Participants acknowledge the limitations of the old TV in receiving modern digital broadcasts and the need for additional equipment, such as a digital converter box or an antenna, to enhance its functionality.

WarInTheHead
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What to do with old 5" portable UHF/VHF TV?

Hello, firstly, this is my first post, yay. I am 23 and just started school Jan 11' for electrical engineering. My grandpa was an electrician. That and reading about Nikola Tesla made me really want to study electricity. I've only taken one real "electrical" class so far, and had a horrible teacher...which was kind of sad. It's the first time I've tried in school, and I got through my first semester with 3 As and 1 B (DC circuits). This semester I will def. get all As. ANYWHO!

My friend recently cleaned out a really old garbagety house and I found a (roughly 5 inch) old Quasar portable TV. The date on it is 1980...almost a decade older than me, haha. So, my dad found a 12 V DC adapter that fit it, and behold : IT WORKS! Turns on, has sound and everything...only problem is it gets no picture. I assume with the switch to digital cable and ****, that that brought about the end of broadcasting in this format (Hell, I may be completely dead wrong about this and they do still broadcast, but this thing is broken? Am I right?)...

My question is, WHAT CAN I DO WITH THIS? I was so excited to see that it works, but I'd really like to use it for something. Is there a way to put a coaxial cable input on this beast, so I can plug my cable into it? (I assume it's black and white, but I don't know without a picture, haha) Although I'm almost a year deep in my schooling, I haven't had much "hands on" electrical experience. I do, however, have a soldering iron, solder, etc, from fixing guitar cables for my friends and I.

So, any ideas (preferably with instructions/tips attached) would be awesome! I'd love to be able to use this awesome find for ANYTHING that may be half way useful/entertaining. Thanks guys/gals!


PS http://www.ebay.com/itm/QUASAR-Portable-5-Television-TV-Radio-Perfect-/290621986011?pt=Televisions&hash=item43aa6b94db

That is ALMOST this tv. Mine doesn't have "buttons" for channels, just a regular dial to go up and down the scale, and a switch to go from UHF to VHF.
 
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WarInTheHead, Welcome to Physics Forums!

If you get an old TV antenna, some flat (300 ohm) antenna cable and connect the antenna to the TV, maybe you could get a picture. I would save it and preserve it. In the future this will be a museum piece with lots of value. Besides that, if you could get old schematic diagrams and operator's manual you could study how it works and learn lots to help you along your way. Try contacting the manufacturer.
 


""In the future this will be a museum piece with lots of value. ""

i wish i'd kept all my TI-99/4A's.

Quasar was a rather high end name as i recall.. if Grandfather has any old stereo equipment be sure to research it before he gives it away.

Practically all TV is now broadcast digital which your little TV can't receive.
i'd peruse local yardsales and thrift stores for a digital converter box and hook it to an antenna. Walmart still sells them, as do a couple other places. BUt they are common in junkshops.

images?q=tbn:ANd9GcS4ODaDwD4tBWjv3k1uiGnSYH3EN6tWMLhLxhxggDQQKnHdf4Oc%20.jpg


your folks probably have one left over- ask your friends and neighbors too, you'll find one.

then go to site antennaweb dot org to find out what channels are available in your neighborhood and what are their frequencies. The little GE converter unit above displays the frequencies for you...

then google "folded dipole antenna".

i built one out of #12 house wire and 3/4 inch PVC pipe. Cost less than $10. That style antenna matches 300 ohm twin lead or, if you solder it to an antenna transformer you can use coaxial cable. Works good to put the transformer in a tee with pipe out each side to support the wire loop, and another pipe out the bottom for a mount. Cable or twin lead comes down that pipe of course.. Attach it with conduit clamps to most anything, my building had a roof mounted airconditioner and i just put the conduit clamp under one of its side panel screws..


My folded dipole antenna is 27 inches long which worked very well for the frequencies in my town.
Make yourself a table of local stations, their frequencies and corresponding wavelengths.
Ideally your loop should be an odd number of half-wavelengths,
but a folded dipole is pretty forgiving
mine is real close to 1/2 wave for one staion
and not far from 3/2 wave for a couple more
and it works GREAT.
images?q=tbn:ANd9GcTwsmCdJvTkGSRNJczpWqXoZ34IIcrViCdoaAAbYJbKIZDsYzMbqw.png


i soldered in an antenna matching transformer (50 cents at Goodwill) and used TV coax for feeder.

oh by the way - on manuals dfor that thing google (and search Ebay) for the "Sam's Photofacts" .
Sams had a symbiotic relationship with the manufacturers and published repair manuals for the trade.
They were the best.
 
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