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Science Forum Index » Electronics Forum » please help: TV with no A/V input
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| Louie |
 Posted: Mon Sep 01, 2003 6:09 pm |
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Guest
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Hi anyone,
i have a small 12volt tv that is based on the KA2915 chip. the tv has an
RF input but no A/V input. i want to know if its possible to tap in
somewhere with a composite signal and bypass the RF stuff.
any ideas?
thanx, Louie |
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| Arthur Jernberg |
| Posted: Mon Sep 01, 2003 6:25 pm |
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Guest
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No: If the engineers wanted it to have this feature they would have
implimented it. For the average user and tinker to attempt to add this
function would be unsafe and probably too expensive. There are readily
available AC/DC teles available that do actually have AVIO ports designed
into them and are sold at a reasonable price.
"Louie" <beavisnbutthead@softhome.net> wrote in message
news:McR4b.329370$uu5.66621@sccrnsc04...
Quote: Hi anyone,
i have a small 12volt tv that is based on the KA2915 chip. the tv has an
RF input but no A/V input. i want to know if its possible to tap in
somewhere with a composite signal and bypass the RF stuff.
any ideas?
thanx, Louie |
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| Dana Raymond |
| Posted: Mon Sep 01, 2003 10:00 pm |
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Guest
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It MAY or MAY NOT have a single A/V (composite audio/video) point in the
design, but you'd need a schematic for it to be sure. My guess (and it would
be a guess) is to look at the signals coming out of the RF tuner section
[sealed silver box]. You may find a baseband composite video signal there
that could lead you to suitable point in the design. It may not be 1Vpp,
etc.
Try one of the repair newsgroups. People regularly help with schematics for
repair, etc.
Dana Frank Raymond
"Louie" <beavisnbutthead@softhome.net> wrote in message
news:McR4b.329370$uu5.66621@sccrnsc04...
Quote: Hi anyone,
i have a small 12volt tv that is based on the KA2915 chip. the tv has an
RF input but no A/V input. i want to know if its possible to tap in
somewhere with a composite signal and bypass the RF stuff.
any ideas?
thanx, Louie |
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| Nirodac |
| Posted: Mon Sep 01, 2003 11:12 pm |
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Guest
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Have you considered one of those modulators that convert AV to RF. Like
they used to use on the old computers like Atari and Commodore, should be
real cheap at a garage sale. Radio Shack may still them.
Ray
"Louie" <beavisnbutthead@softhome.net> wrote in message
news:McR4b.329370$uu5.66621@sccrnsc04...
Quote: Hi anyone,
i have a small 12volt tv that is based on the KA2915 chip. the tv has an
RF input but no A/V input. i want to know if its possible to tap in
somewhere with a composite signal and bypass the RF stuff.
any ideas?
thanx, Louie |
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| Back to top |
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| Louie |
| Posted: Tue Sep 02, 2003 12:47 pm |
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Guest
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Arthur Jernberg wrote:
Quote: No: If the engineers wanted it to have this feature they would have
implimented it. For the average user and tinker to attempt to add this
function would be unsafe and probably too expensive. There are readily
available AC/DC teles available that do actually have AVIO ports designed
into them and are sold at a reasonable price.
yeah that's right but i think it would probably be cheaper to just get a
modulator.
thanx, louie |
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| Louie |
| Posted: Tue Sep 02, 2003 12:51 pm |
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Guest
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Dana Raymond wrote:
Quote: It MAY or MAY NOT have a single A/V (composite audio/video) point in the
design, but you'd need a schematic for it to be sure. My guess (and it would
be a guess) is to look at the signals coming out of the RF tuner section
[sealed silver box]. You may find a baseband composite video signal there
that could lead you to suitable point in the design. It may not be 1Vpp,
etc.
well i have the schematic for the main chip:
http://asu.info.kuzbass.net/documentation/pdf/k/ka2915.pdf
or
http://www.elektro-obecnice.cz/data/pdf/ka/ka2915.pdf
and it looks like the chip is designed to accept external sync and
horizontal and vertical oscillation and external audio RF. but i can't
tell if it can accept external composite video. maybe it does and i
could just filter the composite and put it at pins 14 and 15. anyway
this is my theory.
thanx, louie |
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| Louie |
| Posted: Tue Sep 02, 2003 12:54 pm |
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Guest
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Nirodac wrote:
Quote: Have you considered one of those modulators that convert AV to RF. Like
they used to use on the old computers like Atari and Commodore, should be
real cheap at a garage sale. Radio Shack may still them.
Ray
that might work well enough if i could get a cheap one.
thanx, louie |
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| JeffM |
| Posted: Thu Sep 11, 2003 8:19 pm |
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