What kind of modulator are you using?

[MPodlin]

Dan,


You can pick up a low pass or notch filter from Worthington Dist or Smarthome. The filter you use depends upon what you are going to want to block out and or how many channels you plan to add. As a rule of thumb you should leave at least one empty channel between each modulated channel you use.


Here is a URL that talks about using modulators with digital cable:

http://www.hometoys.com/htinews/feb0...modulators.htm


Also reference the Hometoys article on Video Distribution as it talks about using modulators and filters too:


http://www.hometech.com/learn/video.html


The Pod

[smee]

You can get filters from the usual places:
www.smarthome.com
www.worthdist.com
www.partsexpress.com
The filter you get depends on which channels you want to block out (both ways).

Do the filters block cable modem and/or digital cable signals? If so, then you need to put it in after you split these off. I do not have a cable modem or digital cable so I haven't been able to test it to find out.

For these Blonder-Tongue modulators, I'm assuming that since these are commercial modulators, they're probably capable of putting out a pretty strong signal (but should be adjustable, right?). You might be able to put out a strong enough signal to "blast through" the filter and provide your channels to your neighbors.

[Rupp]

Illudium Q-36 Explosive Space Modulator dummy question

What does 50-440 MHz range mean? What channels does this cover or am I way off base.

[MPodlin]

Rupp,
Looks like around the cable channel range for 2 to 64.

ChannelPlus filter chart


The Pod

[Rupp]

Bear with me here. I know NOTHING about video modulation. So this means I would need an open channel in that range. Right? What if I do not have one? Can I "over write" a channel? TIA Greg

[smee]

Rupp:

That's what the filters discussed above do. They filter out all channels within a specified range.

This prevents incoming channels from interfering with yours and prevents yours from going out to your neighbors.

If you are not using analog cable and just want to run your own channels, then you don't have to worry about interference. Just don't connect your cables to the outside cable.
If the modulator is restricted to cable 2 to 64, this may make it difficult to find a region where you don't mind losing channels. With my cable, I don't have anything over 74 (and don't care about 74 either). I filter out 85(?) through 120(?) or so. My modulators are on 100 and 103.

[smee]

I just tried to edit my above post and it didn't seem to "take."

If you are not using analog cable from outside, you can run whatever you want on your inside wiring - any channels are fine. But if you have any connection to the outside, you'll need to filter.

I still think the best deal ever for modulators was the discontinued Radio Shack 150-1243. These are the $25 modulators mentioned near the beginning of this thread. They are mono only but can be set to a wide range of channels.

I recommend you check with your local Radio Shack and see if they have any. I've checked at a couple and they had them in the back. I don't think anyone ever knew what they were. They always wanted to sell me the "use your new DVD with an old TV" channel 3 or 4 modulators that they push on TV, etc. It's worth asking. I don't think I've seen a better deal for a new modulator.

[MPodlin]

Rupp, Is the MHz range on a filter? if so, the filter is allowing that range of channels to pass through it and blocks out everything above the 440 MHz level. so your tvs will get channels 2-64 from the cable feed, but not receive the channels above 64. So this would allow you to add channels starting at approx 69 through 125. I read somewhere that it is best to allow 10 empty channels from the filter to the first channel you modulate.

The Pod

[Rupp]

Pod,
I was simply asking if the above mentioned $20 modulator would work "over existing cable because it appears it only covers channel's 2-64 apparently.

[electron]

channel 2 on my TV is the scrolling guide which I don't use, I am willing to wipe that one out for sure (could nail MTV and such too lol). So all I do is get this unit, and I am good to go (besides finding some cheap filters for channel 2 I guess), right?

[smee]

After a quick look, I don't see any filters that let you block channels below 50.

Also, they operate over a range of frequencies. The blocking is relatively weak at either end and strong in the middle. It may also go outside the band (weakening channels outside the band that it theoretically blocks). I don't think you'll find something in a reasonable price range that will filter only channel 2 for you.

If the B-T modulators are limited to the above range, I think it makes them much less of a deal than they appear to be otherwise.

There are plenty of channels on my cable that I don't care about and would use if I could (I think my channel 2, for example, is always trying to sell me fur coats). But I think the only reasonable (financially) approach is to grab a block of high channels.

[MPodlin]

I don't think that unit could be used with cable tv. If you wanted to setup your own cable network, these are a great deal. I found an article about SMATV and they talk about if you have existing cable, the you disconnect it and then add hook up an SMATV setup.

The Pod

[George]

Well, my cable only goes up to channel 45 so I order two of them. I'd love to have full MTS stereo sound and I can put the channels in the 50-60 range. To each his own..

[JohnBoy70_99]

I got a notch filter from Tin Lee Electronics it was pricey but you can have them design a filter to block out any channels you want.

It is best to block out a range of channels, in case you want to add cameras later. I blocked out 14-20 on my cable system, and the filter also affected 98,99,21,22.

Note that channels that are adjacent numerically are not always adjacent frequency wise, search for a cable channel frequency chart on the web and you will see what I mean.