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Satellite stations on a 75ohm coax

Last response: in Graphics & Displays
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June 4, 2009 4:26:03 PM

Hello,

I work on a ship where we have 6 tv's all connected with an antenna through a 75ohm coax network. I was wondering if I could receive satellite tv on a pc and distribute them on the 75ohm coax. That way we don't have to buy 6 satellite receivers + cards or re-wire the ship with a coax for satellite tv. Any suggestions?

Thanks in advance.

H.
a b x TV
June 4, 2009 9:25:33 PM

n2o said:
Hello,

I work on a ship where we have 6 tv's all connected with an antenna through a 75ohm coax network. I was wondering if I could receive satellite tv on a pc and distribute them on the 75ohm coax. That way we don't have to buy 6 satellite receivers + cards or re-wire the ship with a coax for satellite tv. Any suggestions?

Thanks in advance.

H.


If you are asking about a "satellite tuner" device for a pc, I have never seen one. Besides, I think all the satellite channels are scrambled - no clearQAM equivalent that I know of. So yeah you'd have to go with 6 satellite settop boxes or else face a mutiny over who gets the remote control :D .

June 4, 2009 9:53:18 PM

Never seen satellite receivers for a PC, but you do not need a PC to do what you want. Considering only analog TV for the moment, you need:

- the satellite dish, which must be aimed and aligned. For your purpose you may need a "mobile" type mount. Depending on ship motion, you may need to shore mount it :( 

- the Satellite receiver/decoder/dvr box and a subscription.

- a Modulator which will take output from the satellite box (composite video, 2xaudio ie yellow/red/white), and output it on a coax cable on any "channel" you want. For our purpose, we'll say "channel 40".

- a Low pass filter attached to your antenna's cable. This device will BLOCK, eg, any channel above 30 or so. So now you antenna wire contains only channels 2 through 30, and is free of any interference above that.

- a "combiner" which is a splitter installed backwards. Attach the filtered antenna coax and the coax from your modulator to the output jacks. Connect the input jack to the cable that feeds your TVs.

You now have an "antenna" signal on the coax that will allow tuning any OTA channel up to 30, plus channel 40 which is whatever is playing from your satellite box.

I do this with 3 DirecTV DVRs (channels 38, 40, 42) and a DVD/VCR (44) to feed all local networks plus whatever is on the four devices to all the TVs in my house.
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June 4, 2009 10:05:42 PM

Note that with one satellite reciever box, you only get one satellite offering.

Another approach is to piggyback the OTA signal AND the basic, encrypted satellite signal to all TVs using a diplexer (I think that's what it is called). If you are lucky, your old wiring may carry the signal well and you will likely need an amplifier.

This would also require decoder boxes at each TV that wanted satellite, and would add $5/box/mo to the ongoing cost. But then every TV gets a choice.

You could also combine the two approaches, depending on how your wiring is laid out.
June 5, 2009 2:25:17 AM

n2o said:
... 6 tv's all connected with an antenna through a 75ohm coax network...

RF is 50 Ohms. Video is 75 Ohms.
June 6, 2009 6:25:27 AM

In Belgium everyone (99.5%) has cable wich is 75ohms. In Belgium we pay €14 a month ($20-$25) to receive the 11 belgian channels via satellite. So if I get it right, with your solution we can only see the channel that the decoder will put on the coax.
Right?

June 7, 2009 7:14:26 AM

Sorry, the "solution" I gave you was a US solution. I don't know anything about TV distribution in Belgium.

If you need a "decoder box" to receive the signal, (in the US) that normally means the output of the box contains only one channel at a time. Therefore 1 box = 1 channel at a time.

Yours may be different.
!