reworked my old TV-VCR set to CRT DTV set.

[wa2ise]

This is my converted CRT analog TV which used to have a VCR in it. The VCR died, and I removed it and installed a Digitalstream converter box in place. This box has user buttons on top. and I had this box sticking out to allow access to them. But I decided that it looked stupid that way, so I installed 3 new buttons on the front, and remounted the box more flush with the front of the set.

[Reece]

That's a great idea. I have a Symphonic set with built-in VCR that was given to me because "it doesn't work" and I haven't even looked at it yet but that would be a great conversion.

[zenith2134]

Lookin' good...sure beats tossing the tv/vcr unit once the vcr dies. Which it always seems to do.

Similar to what I've done with a small JVC crt monitor and a hacked-apart DTV converter....one ac plug, one antenna connection, and it's almost a true portable!

[Electronic M]

Cool idea.

I would imagne that some of the smaller DTV boxes could be made to fit in the cassette slot of these combo machines...

[radiotvnut]

I may have to try that with the next one of these I find with a dead VCR. What did you do to fake the TV chassis into staying on with the VCR removed?

Another thing I've thought of is taking the guts out of a DTV converter and mounting them into a more common 12" AC/DC B&W set. That way, I'd have a convenient portable for when the power goes out.

[wa2ise]

Originally Posted by radiotvnut

I may have to try that with the next one of these I find with a dead VCR. What did you do to fake the TV chassis into staying on with the VCR removed?

This particular set had a control line that would tell the TV to power up or not, which the VCR used to drive. I used a switched 5V power source tapped from the converter box to run this control line. So when the converter boz is turned on, the control line goes from 0V to 5V. It feeds a 4 legged voltage regulator located on the TV circuitboard that has the usual input, output, ground and the 4th pin is an on-off control, similar to a TTL gate input.

For the audio amplifer, I used a computer speaker amplifier, powered off the TV power supply. Found a 12V supply line there. The converter box provides variable level audio, so the converter box's remote does volume.

[dieseljeep]

On the south side of Milwaukee, we refered to that as a "Polish" job.

[Ed in Tx]

Looks well polished to me! Neat idea.

Some of the more common Funai-Symphonic-Philips-Sylvania TV-VCRs might not cooperate as easily though, since their system control is in the syscon microprocessor that's on the VCR board. Would have to make the system sense that the deleted VCR mechanism is in the stop-eject (no tape inside) mode.

[Zenith26kc20]

On the funai, if the IR diodes can be tricked into thinking there is no tape present, it may give an all clear. They go into a conductive state from the IR transmitter diode on the board and prism arrangement when there is no tape. I would try shorting the two receiver diodes and that may trick it. I found a 13 inch last week in the street with it's remote and a sign "works". I took it home and... it works! Tape and all.
The one that could be a bear (impossible) to modify may be the DVD version. On the sets that give me too much trouble I have the phone # of a scrapper. He gives them their "last ride".

[Ed in Tx]

Originally Posted by Zenith26kc20

On the funai, if the IR diodes can be tricked into thinking there is no tape present, it may give an all clear. They go into a conductive state from the IR transmitter diode on the board and prism arrangement when there is no tape. I would try shorting the two receiver diodes and that may trick it...

Yep. Short the tape end and take-up phototransistors. That'll work. And you also would need to affix the rotary encoder mode switch in the Eject position, to remove the mechanism and leave the board in the set to make room for the DTV tuner.

[wa2ise]

Originally Posted by Ed in Tx

Some of the more common Funai-Symphonic-Philips-Sylvania TV-VCRs might not cooperate as easily though, since their system control is in the syscon microprocessor that's on the VCR board.

The ones that adjust the contrast, brightness, hue and color via the remote control would be more difficult to handle. I knew that my set, which has these adjustments as old fashioned analog pots on the side of the cabinet, would be easier to deal with. Also my set had the VCR power source supplies comming from the TV chassis. The chassis doesn't appear to miss the VCR load. I did use a 12V line that fed the VCR to power the audio amp I installed to drive the speakers (the VCR chassis used to do that).

One other thing to do when using new push buttons on the converter boz, or elsewhere in electronics, is to be sure that the metal case of those buttons are grounded. This to divert static sparks to ground and not thru the microprocessors.

[Ed in Tx]

Originally Posted by wa2ise

The ones that adjust the contrast, brightness, hue and color via the remote control would be more difficult to handle. I knew that my set, which has these adjustments as old fashioned analog pots on the side of the cabinet, would be easier to deal with.

Yep some of the earlier TV-VCRs like the Orion built-Emersons, and Aiwa, Sony, Panasonic off the top of my head, were pretty much separate TVs and VCRs with their own power supplies in one cabinet with some relatively simple A/V and control circuitry interconnecting them.