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Digital TV Remodulator

OK, I freely admit that I'm out of my depth with the new digital TV. However, like Joerg, I live so far out in the boondocks that they have to pipe in sunshine. (about 50 miles north of Joerg and about the same elevation, longitude, and problems).

Anyway, we are switching over to digital TV and have the "TV room" pretty well arranged with a LCD HD digital TV, satellite (directv) receiver, and all work well. However, we have a small digital TV in the upstairs room (directly above the downstairs TV) that is only connected right now to an antenna on the roof. As described elsewhere, living 80+ miles from the nearest transmitter doesn't provide a signal worth a damn to a digital TV. SOmetimes fair, sometimes very pixillated, sometimes blue screen of death.

What I'd like to do is take that satellite signal coming into the satellite receiver and transmit it by RF to the TV set above. In the "good old days" you could buy (or easily build) a remodulator that would take the composite audio/video and put out a signal on old VHF channels 3 or 4 (switch selectable) and with a trivial dipole transmit that signal a few dozen feet to another TV.

I've scanned the usual sources (Ramsey, AC6V, etc.) for either a kit, or plans, or some other source to find out how to "remodulate" the digital signal coming from the satellite onto the new format TV and have come up blank.

Anybody got a pointer to at least some basic information on how I might do this in the new digital world? Right now I've got enough design projects for the business to keep me going for twenty years, so if anybody knows of an off-the-shelf box that will do the job, that's great. Yes, I googled what I thought were the appropriate words and came up dry.

Jim

Reply to
RST Engineering - JIm
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Use an old VCR for an analog tuner and connect it to TV via an AV patchcord. Or run composite video over a long cable to it.

Reply to
AZ Nomad

On a sunny day (Thu, 18 Jun 2009 10:24:02 -0700) it happened "RST Engineering

- JIm" wrote in :

Well I do it like this: I have a satellite card in the PC. But I am in Europe.. And I can feed the mpeg stream via the wireless LAN. Now at any location around the house I can get digital TV on a laptop. If the laptop has an analog out connect it to that TV. If it only has VGA out get a nice big monitor and connect it. The satellite transport stream bitrate is low enough for the LAN. Of course you need the right software installed, and the right scripts running, and the right sat card in the main PC, Oh, and the right OS (Linux). OTOH using the PC as sat receiver allows you to record and edit programs, set timers too. Been doing it for years...

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Reply to
Jan Panteltje

Thanks AZ, but the structure of the house precludes any direct wire connection from source to upstairs TV. Neither wire nor IR will cut it; it has to be wireless of some sort.

Jim

Reply to
RST Engineering - JIm

Thanks, Jan, but that's going to Stockholm by way of Buenos Aires. All I want is a simple RF link of no more than 5 meters or so.

Jim

Reply to
RST Engineering - JIm

What kinds of outputs does your satellite tuner have? Inputs on your remote TV?

A DTV modulator isn't going to be a trivial project. You might be better off with analog and the good old RF chan 3/4 solution.

There are wireless HDMI solutions on the horizon (or here now). But not cheap. That's really the only way you are going to preserve the high resolution signal to the remote set (wirelessly). If you can string some cable between your tuner and this remote set, there may be more options.

Or, as Jan suggests, pipe an MPEG stream up where you want it. But this will require a couple of PCs and fiddling with some s/w (the satellite folks make it difficult for people to access raw MPEG).

--
Paul Hovnanian  paul@hovnanian.com
----------------------------------------------------------------------
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Reply to
Paul Hovnanian P.E.

Jim: Can the upstairs TV still receive regulat NTSC transmissions as well?

At least with Dish Network satellite receivers (we have one), some have RF remote controls and RF outputs, whereby you can select pretty much any UHF channel for the output. While it's intended to be hooked to coax to run to your TVs, clearly with little more than, say, a MMIC amplifier and an antenna, you'd be able to transmit to from the satellite receiver back up to the TV in the bedroom (and still be all legal if you keep the RF power low enough).

I suspect it will be awhile before we see cheap boxes that convert composite/S-video/component/etc. to ATSC video -- I would guess that the encoders are still a lot more than a "single chip" solution, since the MPEG encoding process requires a lot more horsepower than decoding.

---Joel

Reply to
Joel Koltner

Not DTV, but the company that peddles X-10 stuff also has wireless TV relay transmitters. I doubt anyone will develop those for DTV, there just isn't enough market. So you could hang a converter box to the sat receiver output (maybe where it comes out on Ch 3,4), convert to analog and send it up there wirelesssly.

Attention, very "loud" and obtrusive web site but shipments from them have always been ok:

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Of course the manly thing to do would be to get yourself a Bosch Bulldog hammer drill, don mean-looking eye protection, have at it, then run a proper cable. That's how it is here, star runs from an amplifier closet.

And yeah, DTV can be the pits. Before the cut-off we'd switch to Ch13 analog when the signal on Ch 13-1 went bye-bye during the evening news. Now we crack out the stack of rommee cards.

--
Regards, Joerg

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Reply to
Joerg

1) please don't top post. backwards everything reading prefer don't people Most 2) it was only a suggestion. You mentioned the room being directly upstairs. Shouldn't be too hard to run a wire.

For the VCR method, you don't need a direct wire. Use an analog RF modulator. Receive it with the VCR located at the remote TV. run the composite signal from VCR to TV with a patchcord.

Reply to
AZ Nomad

This would be an extremely expensive undertaking for the home-brew electronics buff, I fear.

The signal coming down from the satellite simply isn't in a format which is even close to being compatible with the digital tuner in an ATSC television set. The incompatibility exists on several different levels.

The least-expensive approach would be to do pretty much as you had done before... take the *analog* output from a DirecTV receiver, and ship it downstairs to a second TV. Using an S-Video cable and a stereo-audio cable will give you pretty good picture and sound quality. Composite video isn't quite as good, visually. Remodulating the analog signal onto RF (e.g. onto channel 2 or 3) is defintely last choice in terms of quality.

If you wanted to take the output coming out of the DirecTV receiver's analog out, and convert it to ATSC digital to "beam downstairs", you'd need a full MPEG-4 / ATSC encoder as well as an RF modulator. Expensive.

Frankly, I think your best bet would be to order a second satellite receiver and a multiswitch, and feed both receivers from your existing dish. This will let you watch two different programs independently. The additional cost is relatively small.

--
Dave Platt                                    AE6EO
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Reply to
Dave Platt

I've got one of those.

I consider it essentially useless. It operates in the 2.4 GHz ISM band... the same place as 802.11b, a lot of cordless phones, and most microwave ovens.

Turn on a microwave oven anywhere in the house (or in any of the nearby neighbors' houses) and the video signal is disrupted and the audio roars staticbuzz at you.

--
Dave Platt                                    AE6EO
Friends of Jade Warrior home page:  http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
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Reply to
Dave Platt

Yeah, it can be similar with WLAN. I often get five bars (full strenght on the crude RSSI thingie in the laptop) in the living quarters of the house here. But that's the signal from a cordless phone, if that doesn't transmit it's between zero and one bar and very iffy :-(

--
Regards, Joerg

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Reply to
Joerg

Speaking of cordless phones... the DECT ones @ 1.9GHz might give your wireless network a bit more breathing room. We have a relative of this one:

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...and it even uses regular batteries (AAAs), like you wanted.

---Joel

Reply to
Joel Koltner

On a sunny day (Thu, 18 Jun 2009 11:39:00 -0700) it happened Joerg wrote in :

I do not get it, here I still have to see the first dropped packet with WiFi. Linksys WAPs are good. Microwave on or not, GSM on or not, dunno about wireless phones. On the Sweex USB WiFi adapter I had before that, there was constant link loss..

But I have a free standing house, maybe that makes some difference.

Reply to
Jan Panteltje

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Yep, waiting until they go on sale again at BestBuy. Last time they did they said they were "out".

--
Regards, Joerg

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Reply to
Joerg

Well, American house are a bit larger :-)

Plus ours has aluminum backed fiber insultation in inside walls. Guess the builders wanted to be extra good.

--
Regards, Joerg

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Reply to
Joerg

loss..

Well! If they wasted foil-back on an interior wall, you have to wonder if the foil is on the proper vapor barrier side on the exterior walls ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
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Reply to
Jim Thompson

On a sunny day (Thu, 18 Jun 2009 12:49:58 -0700) it happened Joerg wrote in :

loss..

Yep, life in a Faraday cage has its own problems I guess :-)

Reply to
Jan Panteltje

loss..

No problems so far, in 40 years. I've had to open an exterior wall in a bathroom and it all looked brand-spanking new and clean in there.

The house did not come with tin foil hats though :-)

--
Regards, Joerg

http://www.analogconsultants.com/

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Reply to
Joerg

loss..

Could be useful if you have a big house and don't want to heat all of it in the winter. Having a vapour barrier on the warm-in-winter side is a big help.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
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Reply to
Phil Hobbs

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