Building a PVR: Connection to coaxial Jack

  • Thread starter Thread starter Analabha Roy
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A

Analabha Roy

Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type. Unfortunately, my TV only has a 75 Ohm
coaxial connector (the one for the analog cable for the cable-tv or VCR
etc), no composites or S-Video. I was wondering if it is possible to
connect the tv-out port of the card to the 75-Ohm connector of the TV using
some sort of adapter, and whether such things are available. I googled but
only saw adapters for composite-to-RCA or composite-to-S-Video and various
permutations of composite, RCA and S-Video, but nothing for 75-Ohm
coaxials.

Can anyone inform/educate me as to whether this is doable?


Thanks,
AR
 
Analabha said:
Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type. Unfortunately, my TV only has a 75 Ohm
coaxial connector (the one for the analog cable for the cable-tv or VCR
etc), no composites or S-Video. I was wondering if it is possible to
connect the tv-out port of the card to the 75-Ohm connector of the TV using
some sort of adapter, and whether such things are available. I googled but
only saw adapters for composite-to-RCA or composite-to-S-Video and various
permutations of composite, RCA and S-Video, but nothing for 75-Ohm
coaxials.

Can anyone inform/educate me as to whether this is doable?


Thanks,
AR
Click to expand...

Put simply, the standard coaxial cable input to a television is meant
for one thing: accepting an RF (radio frequency) signal such as is
transmitted over the air from a television transmitter (or coming from a
cable television setup, VCR, or equivalent). So what you really need is
to convert the video and possibly the audio too into something that
passes for a broadcast-type signal. The device for the job is an RF
modulator. Sadly the process of converting good video from an S-video
jack into RF then putting it into a television then turning it back into
a video signal and then displaying it is costly in terms of quality. But
if you still want to do it, a quick read of this article might help you out:

http://hometheater.about.com/cs/dvdlaserdisc/a/aadvdrfmoda.htm
 
Analabha said:
Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type. Unfortunately, my TV only has a 75 Ohm
coaxial connector (the one for the analog cable for the cable-tv or VCR
etc), no composites or S-Video. I was wondering if it is possible to
connect the tv-out port of the card to the 75-Ohm connector of the TV using
some sort of adapter, and whether such things are available. I googled but
only saw adapters for composite-to-RCA or composite-to-S-Video and various
permutations of composite, RCA and S-Video, but nothing for 75-Ohm
coaxials.

Can anyone inform/educate me as to whether this is doable?


Thanks,
AR
Click to expand...

Yep. You need a gadget called a RF Modulator. Like this:

http://tinyurl.com/5f6m6
 
Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type. Unfortunately, my TV only has a 75 Ohm
coaxial connector (the one for the analog cable for the cable-tv or VCR
etc), no composites or S-Video. I was wondering if it is possible to
connect the tv-out port of the card to the 75-Ohm connector of the TV using
some sort of adapter, and whether such things are available. I googled but
only saw adapters for composite-to-RCA or composite-to-S-Video and various
permutations of composite, RCA and S-Video, but nothing for 75-Ohm
coaxials.

Can anyone inform/educate me as to whether this is doable?
Click to expand...


You'd need what's commonly called an RF modulator box. It
typically takes a composite input and outputs the single to
the coaxial as channel 3 or 4 (you tune the TV to that
channel). They're significantly more expensive than a mere
cable or plug adapter, roughly $60.

Well I'm wrong- thanks to modern technology, these basic
boxes can be had for under $20 now, for example,

http://froogle.google.com/froogle?q=television+RF+modulator&scoring=p

http://www.costcentral.com/proddetail/Belkin/F8V3063/F40564/froogle/

Some of them may be better than others- I don't know which
are good or bad relative to the rest.
 
Analabha Roy said:
Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type.
Click to expand...

Nope... These *INPUTS* are of the coax cable, svideo and composite video.
You put your signal INTO the PVR card here.

It's your VIDEO card that has the output, and it will be at worst composite
video, second is Svideo and finally VGA or DVI which is MUCH better.

If your TV doesn't even have composite in, spend $100 on a new TV before you
spend it on a tuner card.
 
Analabha said:
Hi,

I'm trying to build a PVR machine that I can watch/record TV with. I was
thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
However, the tv-out ports in those and similar cards seems to be either of
the composite type or S-Video type. Unfortunately, my TV only has a 75 Ohm
coaxial connector (the one for the analog cable for the cable-tv or VCR
etc), no composites or S-Video. I was wondering if it is possible to
connect the tv-out port of the card to the 75-Ohm connector of the TV
using some sort of adapter, and whether such things are available. I
googled but only saw adapters for composite-to-RCA or composite-to-S-Video
and various permutations of composite, RCA and S-Video, but nothing for
75-Ohm coaxials.
Click to expand...


Thx all. Looks like I'm in business.
 
Analabha said:
Analabha Roy wrote:





Thx all. Looks like I'm in business.
Click to expand...


Before you spend money on a RF modulator, which is the correct solution:

All video VCR s contain a modulator which will give you an output on TV
RF channel 3 or 4. The mechanical parts usually fail first, so units
are often available for free. Simply connect the video and audio
outputs from the computer to the corresponding inputs of the VCR, set
your TV to channel 3 or 4, and you're in business.
 
Most VCRs have RF input and OUTPUT and also Composite input and
output.
If you own a vcr, you should know what to do.

I own a RF input only tv too. So I use 2 broken VCRs for all kinds of
connections.

On Wed, 28 Sep 2005 20:16:55 -0500, Analabha Roy

=>Hi,
=>
=> I'm trying to build a PVR machine that I can watch/record TV with.
I was
=>thinking of using the Hauppauge PVR 150/250/350 card for a tv tuner.
=>However, the tv-out ports in those and similar cards seems to be
either of
=>the composite type or S-Video type. Unfortunately, my TV only has a
75 Ohm
=>coaxial connector (the one for the analog cable for the cable-tv or
VCR
=>etc), no composites or S-Video. I was wondering if it is possible to
=>connect the tv-out port of the card to the 75-Ohm connector of the
TV using
=>some sort of adapter, and whether such things are available. I
googled but
=>only saw adapters for composite-to-RCA or composite-to-S-Video and
various
=>permutations of composite, RCA and S-Video, but nothing for 75-Ohm
=>coaxials.
=>
=> Can anyone inform/educate me as to whether this is doable?
=>
=>
=>Thanks,
=>AR
 
Noozer said:
Nope... These *INPUTS* are of the coax cable, svideo and composite video.
You put your signal INTO the PVR card here.
Click to expand...


For most cards, yes. But from what I read in the knoppmyth forums and from
the manual at hauppauge's site, the PVR 350 has a port called A/V OUT (in
addition to S-Video in). That's supposed to be for the TV-out from the PVR.
The firmware supports MPEG decoding, which it would have to do in order to
feed raw video data OUT of the card.

Please correct me if I'm wrong.
 
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