opposite of an RF Modulator?

M

mm

Jan 1, 1970
0
Does there exist the opposite of an RF Modulator? Something that will
take RF and turn it into digital for a digital tv?

Details:
I don't need this yet but I'm trying to plan ahead. What will I do
when I have one or two digital tvs, but I'm sending analog to all the
tvs in the house? I don't have the energy anymore to install
homeruns from the DVDR to any tv but the one in the same room. All
the rest are in series ther. I don't have the energy to run RCA
cables for composite or component inputs.

Right now, I use a DVDR and an RF modulator to take digital over the
air tv, detect it, and convert it to analog. and I send it to the 7
tv's I have, one in each room, and maybe one for the deck too. After
some effort, with some help from you guys, this works fine. The attic
antenna goes to the DVDR in my bedroom and soon, I'll have a set-top
box too (and a Channelplus modulator outputing two inputs on separate
channels), so I can record one show and watch a second, while sending
the second throughout the house.

I'm not going to buy 8 digital tv's at one time, and in reality, I'm
only going to get them one at a time over the next 10 or 20 years,
dpending on what I see at yard sales.

So what will I do when I have one or two digital tvs, but I'm sending
analog to all the tvs? I don't have the energy anymore to install
homeruns from the DVDR to any tv but the one in the same room. All
the rest are in series. I don't have the energy to run RCA cables for
composite or component.

Can I convert the analog back to digital for the digital tvs?

R

Rich Webb

Jan 1, 1970
0
[snippety snip]
So what will I do when I have one or two digital tvs, but I'm sending
analog to all the tvs?

Some (many? most? all?) current generation U.S. flat-screen television
receivers include both NTST (analog) and ATSC (digital) tuners. The NTSC
tuners work the same way on the flat-screens as they do for the older,
CRC-based models, so you may not need to make any changes to your
distribution system at all.
Can I convert the analog back to digital for the digital tvs?

Not easily or cheaply. The consumer-grade market for such a gizmo is
very small. If you wanted to do the heavy lifting, the specs for each
are available and it certainly could be done in principle. Some guy with
a web page has probably already done it but you're not likely to find
one on the shelf at WalMart.

W

William Sommerwerck

Jan 1, 1970
0
I think this is a troll, but...

To make a long story short... Almost all TVs have inputs for analog audio
and video. By that I mean "baseband" (not RF) signals, such as composite
NTSC or component 1080p. With high-quality cabling, you should be able to
run these signals to multiple sets.

U

UCLAN

Jan 1, 1970
0
mm said:
Does there exist the opposite of an RF Modulator? Something that will
take RF and turn it into digital for a digital tv?

Well, a RF *demodulator* takes analog RF and converts it to analog A/V. A
A->D converter will convert that to digital.
Can I convert the analog back to digital for the digital tvs?

A A->D converter will do the trick. $$for video. Question: For the digital TVs, why not just use the original digital signal? D David Nebenzahl Jan 1, 1970 0 I don't know if those outputs are made to drive -multiple- sets. I believe they are only 1:1. They still require impedance matching,too. Just curious: what *is* the impedance of such cables? I'm guessing it's not the 50 or 75 ohms of RF cabling. M mm Jan 1, 1970 0 Well, a RF *demodulator* takes analog RF and converts it to analog A/V. A A->D converter will convert that to digital. A A->D converter will do the trick.$$ for video.

Question: For the digital TVs, why not just use the original digital
signal?

I don't know. I guess I can. I didnt' think of it. Thanks.

I guess I would have to use a couple spitters to make a route around
the RF modulator, and then I would be running analog and digital on
the same co-ax, right?

M

mm

Jan 1, 1970
0
[snippety snip]
So what will I do when I have one or two digital tvs, but I'm sending
analog to all the tvs?

Some (many? most? all?) current generation U.S. flat-screen television
receivers include both NTST (analog) and ATSC (digital) tuners. The NTSC
tuners work the same way on the flat-screens as they do for the older,
CRC-based models, so you may not need to make any changes to your
distribution system at all.

Well that would be great. I'll keep my eyes open for that.
Not easily or cheaply. The consumer-grade market for such a gizmo is
very small. If you wanted to do the heavy lifting, the specs for each
are available and it certainly could be done in principle. Some guy with
a web page has probably already done it but you're not likely to find
one on the shelf at WalMart.

Okay.

Thanks to you and to Bob, AZ, David, William (even though he thinks
I'm trolling!) Jim, David, Michael, and UCLAN.

W

William Sommerwerck

Jan 1, 1970
0
Thanks to you and to Bob, AZ, David, William (even though
he thinks I'm trolling!) Jim, David, Michael, and UCLAN.

There are some questions that -- to me, anyway -- have such obvious and
simple answers, that it's easy to believe some posts are trolls.

U

UCLAN

Jan 1, 1970
0
mm said:
I don't know. I guess I can. I didnt' think of it. Thanks.

I guess I would have to use a couple spitters to make a route around the RF
modulator, and then I would be running analog and digital on the same
co-ax, right?

If you split it off to the digital TVs *before* it goes into the D->A
converter box, then it would be only digital - right?

P

[email protected]

Jan 1, 1970
0
Does there exist the opposite of an RF Modulator? Something that will
take RF and turn it into digital for a digital tv?

Details:
I don't need this yet but I'm trying to plan ahead. What will I do
when I have one or two digital tvs, but I'm sending analog to all the
tvs in the house? I don't have the energy anymore to install
homeruns from the DVDR to any tv but the one in the same room. All
the rest are in series ther. I don't have the energy to run RCA
cables for composite or component inputs.

Right now, I use a DVDR and an RF modulator to take digital over the
air tv, detect it, and convert it to analog. and I send it to the 7
tv's I have, one in each room, and maybe one for the deck too. After
some effort, with some help from you guys, this works fine. The attic
antenna goes to the DVDR in my bedroom and soon, I'll have a set-top
box too (and a Channelplus modulator outputing two inputs on separate
channels), so I can record one show and watch a second, while sending
the second throughout the house.

I'm not going to buy 8 digital tv's at one time, and in reality, I'm
only going to get them one at a time over the next 10 or 20 years,
dpending on what I see at yard sales.

So what will I do when I have one or two digital tvs, but I'm sending
analog to all the tvs? I don't have the energy anymore to install
homeruns from the DVDR to any tv but the one in the same room. All
the rest are in series. I don't have the energy to run RCA cables for
composite or component.

Can I convert the analog back to digital for the digital tvs?
Phrase your question properly and you will get better results.

PlainBill

P

[email protected]

Jan 1, 1970
0
Probably unnecessary.

Almost all digital-cable TVs can receive and decode both ATSC
(digital) and NTSC (analog broadcast/cable) signals. They can look at
any proper 6 MHz slice of the broadcast spectrum, look at the signal
in that range, determine whether it's NTSC or ATSC, and display it
properly.

You can mix NTSC signals (e.g. the "channel 2/3" modulated output from
a VCR or DVD player) with ATSC digital, as long as you don't try to
put both on the same channel. The best way to do this is with a
proper single-channel combiner.

You ought to be able to arrange a setup which takes your incoming
antenna signal (which will consist almost entirely of ATSC signals),
buffers/amplifies it, mixes in a modulated NTSC signal from the DVDR
modulator (on a channel not used for ATSC), and distribues this out to
all of the TVs. Tune to an ATSC channel and they'll detect and decode
the corresponding digital signal. Tune to the channel you're using
for NTSC analog from the DVDR, and that's what they'll show.

This will be *much* less expensive than trying to take the analog
output of the DVDR, encode it into ATSC digital format, modulate it,
and mix it onto the cable.

The best video quality from the DVDR would be via HDMI (or component,
or S-Video, or composite, in that rough order) rather than via
modulated RF (which is often soft and blurry looking) but you'd need
home-run cables from the DVDR and some form of distribution amp to do
these.
Only if you are willing to settle for 'less than analog boradcast
quality signals'. Recall that anyone who compared the quality of the
RF signal output of a VCR to the composite signal quickly decided that
it was worth buying the composite cables. And a component connection
offers even better performance.

Also, unlike others, I do a little research. The last two DVD players
I purchased don't even have RF outputs. One, a Toshiba, DOES have an
HDMI output.

Doing a little research, the ZvBox® 170 appears to do exactly what
the OP proposed. Not surprising, that's what it was designed for.

PlainBill

U

UCLAN

Jan 1, 1970
0
Only if you are willing to settle for 'less than analog boradcast
quality signals'. Recall that anyone who compared the quality of the
RF signal output of a VCR to the composite signal quickly decided that
it was worth buying the composite cables. And a component connection
offers even better performance.

Also, unlike others, I do a little research.

Well try reading what is posted instead. It was stated that the best quality
video would be with HDMI, with component, S-Video, composite and RF trailing
would differ (if at all.)

P

[email protected]

Jan 1, 1970
0
Well try reading what is posted instead. It was stated that the best quality
video would be with HDMI, with component, S-Video, composite and RF trailing
would differ (if at all.)
It has been pretty well established that the best possible display in
a HDTV is with a Blu--Ray player and an HDMI connection. It goes
without saying that the HDTV must be capable of 1080P performance
(although all intelligent people agree that 1080I is pretty darn
close), with lower resolutions (of both the source signal and the
native resolution of the display) giving poorer results.

What is often ignored is the fact that an antenna that gives a good
signal and a broadcaster that does not limit their signal quality in a
number of ways (IE, broadcasting in 720P) will give a picture that is
ALMOST as good as Blu-ray. The chief deficiency is, of course, that
OTA broadcasts are either 1080I or 720P.

Given the OP's desire NOT to run additional cables, and a desire for
sharing top quality signals with all TVs, it thus follows that he must
use an ATSC modulator for each source and combine them onto the single
coax.

PlainBill

U

UCLAN

Jan 1, 1970
0
It has been pretty well established that the best possible display in
a HDTV is with a Blu--Ray player and an HDMI connection. It goes
without saying that the HDTV must be capable of 1080P performance
(although all intelligent people agree that 1080I is pretty darn
close), with lower resolutions (of both the source signal and the
native resolution of the display) giving poorer results.

What is often ignored is the fact that an antenna that gives a good
signal and a broadcaster that does not limit their signal quality in a
number of ways (IE, broadcasting in 720P) will give a picture that is
ALMOST as good as Blu-ray. The chief deficiency is, of course, that
OTA broadcasts are either 1080I or 720P.

zzzzzzz...

V

[email protected]

Jan 1, 1970
0
*+-I don't know if those outputs are made to drive -multiple- sets.
*+-I believe they are only 1:1.

Ouch. Pet peeve.

I had learned to "design fan out of five", so I had a y-connector
using 2,3,8,20 RS232 pins for terminal and printer to modem. Then in
1983 I got an Epson computer, and they didn't support fan-out of
five. It was more like 150% instead of 500%.

THe Fan out of five equipment was all American made. So I never
bought the "Japanese quality" myth. (My family has been orginal owner
for twenty years each on five USA-made V8 cars built 1960-1980.)

- = -
Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus, BioStrategist
http://www.panix.com/~vjp2/vasos.htm
---{Nothing herein constitutes advice. Everything fully disclaimed.}---
[Homeland Security means private firearms not lazy obstructive guards]
[Urb sprawl confounds terror] [Phooey on GUI: Windows for subprime Bimbos]

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