I found this little TV at a thrift shop and had to snatch it up mainly for a
portable NTSC decoder as it has a A/V input. The TV is functionally obsolete
now as analog signals are no longer broadcast, and it shows.This TV has a 2.5 inch thin film transistor, twisted nematic display. With the TFTs it has a fairly good contrast ratio, but as its screen is simply twisted nematic, its viewing angles are pretty limited. The up/down angle is what's gated by the display, though side to side is not too bad.
This TV has a broadcast antenna, has a 6V 550mA center positive power input, earphone plug, A/V input. It switches between the VHF channel 2-13 and UHF channels 14-69 bands. A control for volume and brightness are along the side. A stand can be unhooked from the rear, and the battery compartment is on the FRONT of the box, where it holds three AA batteries. I measured it to draw about 450 to 500mA, and thus would only get an hour with NiCds, few hours with NiMH, and the manual reports about 3 hours with alkalines. This would count as a "medium drain" device as it looks like it doesn't have loads in the ampere range.
Upon turning on by sliding the select switch on the left, a red band (in VHF) or a green band (in UHF) scans across the screen as it looks for the carrier waves of channels indicated on the bezel (note there is a big gap between 6 and 7, due to how the FCC allocated the channels). In 2016, no broadcast channels are available so it will continually scan and never stop. Plugging in an 1/8" TRS AV plug will stop the scanning and display the NTSC input. This is probably the main usefulness of this device in today's world.
I was able to test the broadcast receiver of this unit by using a RF modulator. As RF modulators generate very weak signals, I had to basically touch the output of the modulator to the antenna to "pick up" a signal. There's a 1/8" blocked off hole on top that probably was meant for an antenna input, but is not present on this device. In VHF mode, the scanning stopped at channel 3 where I had set my RF modulator. With the direct connection, the picture looks fairly clear, though using the A/V connector is cleaner.
I had been trying to use a 5" CRT portable TV as a test NTSC receiver, alas that unit is way too clunky as I did not have the 8 D cells to fill it. Holy crapola that's a lot of large batteries. This unit with a smaller screen is more reasonable, plus it's got a color display.
The OEM of this device is probably Casio as I have an EV-750B that looks and behaves very much like it.
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