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cctv1234

@southslope.net

[IA] Mediacom Iowa City/Coralville frequency assignments?

Is there any way to find out what frequencies Mediacom uses for various services/channels in the Iowa City/Coralville area? I want to inject CCTV channels into my feed, which I can do using analog cable channels in the range of 65 to 125 (from 450 MHz to 850 MHz)

For this to work I need a filter to block out the channels I'm using, but I have no idea what frequencies are used for what. I'd prefer to block out frequencies that are used for cable modems since I use DSL.

Is there anywhere I can find out which frequencies are used for cable modems in the Iowa City area? Is this information available anywhere or does anyone know? If that doesn't work out, how do I know for instance what HD channels the various analog channel frequencies are used for? Perhaps I could find a frequency range used for some premium or PPV channels I don't get.

The only thing I've found is Mediacom's channel guide, which does show the subchannels for digital SD (i.e. Big Ten Network is 51-25, ESPN is 55-5, etc.) and the unscrambled HD channels (113, 114, 115, 117, 119) If I carve out channels 70-75, maybe that's fine, maybe I'll blow away ESPN HD or something important like that.


OldCableGuy

@planetcr.net
Pretty much everything from 52-800MHz is used at this point. You're going to need to pick channels you don't want and notch filter them out yourself. Or you can pick any of the channels that only carry encrypted QAM channels.


MediacomChad
Mediacom Social Media Relations Team
Premium,VIP
join:2010-01-20
Gulf Breeze, FL
kudos:121
reply to cctv1234
Since you're not using our internet service, modems for your area use 100-140 MHz. You will still want to use a notch filter to prevent your CCTV signal from back-feeding to everyone else nearby.

If you were interested in try out our internet service, feel free to message me with your account info and I'll see what kind of promotions we have available in your area

Nexis

join:2002-04-29
USA
reply to cctv1234
There are a few options you could try out. There are QAM modulators you can get to inject your signal. Talk to your local office about what the local injection channel is. We use different channels in different systems for this. I know out of the Cedar Rapids head end QAM 5.4 will inject on 998 on digital boxes. Advantage here is there is a channel on your digital box that will display this without having to switch inputs. I would advise against using the downstream DOCSIS channels for your insertion. If something goes wrong and you end up pushing your CCTV signal back out to plant, you may end up with your cable disconnected in a hurry.

When you do inject you would need to run a DC in reverse to inject the signal properly. incoming signal on the through leg, jumper to your splitter on the input, and the signal to inject on the tap leg. This will degrade your signal and may require a house amp to compensate, but will clamp down on your CCTV from reaching plant. The notch filter would be placed on the output leg of the DC between you and outside plant.


cctv1234

@khamsin.net
I have a Channel Plus 5545 four channel RF modulator, it can't do QAM just regular NTSC RF, on UHF channels 14-69 or analog cable channels 65-125. There's no reason to spend many hundreds of dollars on a QAM modulator when I already own something that will work.

Now I'm not sure if injecting an analog signal will work with my Tivo Premieres (using a cable card) or mediacom HD receivers, but if I can't tune the analog CCTV channels using those I'll simply add a splitter at each TV and have the signal run into the TV's RF connection and be able to tune it that way. If it were possible to run additional cables I would have the CCTV run directly to each TV's RF connection over a separate coax, but that's simply not possible with the way my house was built.

Unfortunately it appears I can't use the frequencies being used for cable modems since 100-140 MHz is well outside the modulator's range. I need to use channels between 450 and 800 MHz. I have found several possible filters to use, all of which are unidirectional so there will be no signal backfeeding to worry about. I just need to know what frequencies I can use.

If I pick channels carrying encrypted QAM like OldCableGuy suggests, how will I know what channels I'm wiping out? I can't just choose them at random, all the HD channels are encrypted, and I obviously use many of them. There has to be some way to know what channels are assigned to what frequencies. On my Tivo I can tune a channel and see what frequency it is using via the cable card menu, for example ESPN HD channel 830 is 219 Mhz. I can tune channels I don't get, when I tune PPV channel 501 it shows 747 MHz.

I suppose I could tune every single channel, see what frequency it is using, and create a huge spreadsheet, but surely it is possible to get this information from mediacom? I realize it would be subject to change, but I doubt they move things around all the time for no reason. If I had a list of the frequencies for every channel, I could choose exactly what frequencies to step on knowing I won't wipe out anything I care about. I don't get PPV or any of the movie channels since I use Netflix and Amazon. If there is a large block of those somewhere above 450 MHz it'd be perfect for my needs.

Nexis

join:2002-04-29
USA
reply to cctv1234
I don't think we have anything on 119 to 125, but I'm not 100% sure. I can take a peak on monday when I get back in the office


OldCableGuy

@communications.net
reply to Nexis
Nexis thanks for your post, that's unbelievably good info...

k9iua6

join:2004-05-23
Dubuque, IA
kudos:1
reply to cctv1234
As you probably know, you need to be very careful about injecting a signal that can migrate away from your home and affect others. At the school where I work, which has a couple of analog video cameras with modulators to project chapel services to TVs in adjacent rooms, the local Mediacom office asked us to disconnect from their cable system anytime we used the camera (such as by using a manual A-B splitter switch). The other option was to upgrade our modulators to newer models that could handle more channels. I don't recall the channels they said we could use. If I think of it, I can check with our maintenance supervisor, although what works in Dubuque for available channels may not necessarily match in Iowa City/Coralville.

k9iua6

join:2004-05-23
Dubuque, IA
kudos:1
reply to cctv1234
Okay, I checked back on some old e-mails from my maintenance supervisor at work, where we have a couple of internal cameras we share on the coax network. The instructions we received from the Dubuque technicians is that they are directing all customers in our market area who have cameras and other internal programming to use channels 16, 17, 18, or 19. That doesn't help you with the modulators you already have, as it didn't help us here either, as similarly our modulators were high-band ones. We ended up shifting to the A-B switch method, where the TVs can only be configured to show cameras on one switch setting using higher channels or access to Mediacom DTAs for cable television viewing with the other switch setting.

Nexis

join:2002-04-29
USA
reply to cctv1234
Channels 119 to 125 are not used in the Iowa city area at the moment. You would want to run a notch filter to prevent the signal from reaching plant, and insert with a DC in backwards.