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Discussion Starter · #1 ·
I want to distribute the output from my HTPC to all TVs in the house in the highest quality and least invasive way possible. Thinking about running a test to see how RF modulation & distribution would look.


Note: I live in Oakland, with standard analog cable from 2->60, digital cable from 120->591.


I think I need to buy:

1) ChannelVision E-1200 modulator: To modulate input to a particular channel. I was thinking 90 since it's a long way from 60, which is my high channel.

2) ChannelVision 3102-78 filter: To block out upper channels

3) ChannelVision HS-2 combiner


Q2: Will that 3102-78 block out my digital cable channels above 78? Or just the analog, of which I have none above 78?


Q3: Due to low-power signal from the cable company, I currently have the inbound cable go through a RadioShack 4-way amp&splitter, with 1 run to my HTPC. Should I also get a powered 2-way splitter, and run from:

Cable Company drop->

- HTPC

- Combiner which would also have the HTPC->filter->modulator line coming in.


Combiner would then go to 4-way splitter for distribution to TVs around house.


Is this right?
 

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Quote:
Originally posted by IVB
Q2: Will that 3102-78 block out my digital cable channels above 78? Or just the analog, of which I have none above 78?
A filter will block frequencies, not channels. Channel 78, the limit of the filter you're looking at, will cut off all frequencies above 546Mhz. Digital cable works on the higher spectrum of the cable signal, which is different for each cable co. If you have digital cable, you will need to split off the main line before adding the filter.
 

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Discussion Starter · #3 ·
So does that mean there's no way to combine a digital cable signal with another signal?
 

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Cable modems utilize frequencies in the 820 MHz region The digital carrier is up in that area as well. It is very difficult to add modulated channels to a digital cable system unless you resort to single channel elimination filters. And even here you need to be careful. When digital cable first came on line we had to remove our single channel filters form many systems as they caused digital cable not to work. This may have been a bandwidth issue as these filters only had a pass through ability to 350Mhz. Perhaps if they pass through was 550 or higher it might have worked. You may need to waste money in order to experiment. Sometimes the only channel available is 125.


Alan
 

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Depends. You may be able to use a notch filter and only block out a few channels in the analog spectrum. Look up manufacturers notch filters and see if the channels they block are acceptable to you.
 

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Channel elimination filters are notch filters. Hence the necessity that they have sufficient bandwidth not to interfere with the digital carrier. Microwave filters makes some of the best channel elimination filters for the industry and they were not able to help. They may have more experience now then three years ago. Nonetheless, you may need to purchase equipment to see if it works and you may not be able to return it. Channel elimination filters are not very expensive but it depends on the frequency; perhaps 120 for something in the Ultra band.


Alan
 
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