Need to broadcast over building tv's

[Dave109 0]

I need to find a way to be able to switch over our buildings cable feed, substitute material we have on DVD/VCR that would broadcast on all channels of buildings tv's.

[Soundy 1]

You need a "CATV modulator". Try googling that phrase, there are hundreds of products out there.

[shoreviewsecurity 0]

Hi and welcome to the forum.

 

Having a tremendous amount of Cable TV experience I know exactly what you need to do however I need additional Information...

 

How many cameras/channels are you looking to insert??

 

Many many variables to deal with…

 

Does your cable company provide digital channels?? Most do. The reason I ask is typically a cable company will insert these digital channels in a certain frequency range. You will need to determine this. Notch out that frequency range and you will have more problems.

 

Let's assume one channel insertion...

 

In a nutshell, you will need to first find an open 6Mhz slot to insert your channel. Let's further assume channel 78. Purchase a notch filter to filter out that 6Mhz channel coming in from the cable company ( 547.250 - 553.250 ). Purchase a modulator with the same frequency as the open channel - channel 78. If there is a cable channel on either side of the channel, you will need to buy a quality notch filter. If you don’t, you run the risk of filtering out adjacent channels.

 

All the above is assuming the incoming cable line is not “Hard Lineâ€

Edited October 18, 2009 by Guest

[Dave109 0]

I would prefer to cut away from the incoming cable line and cut over to to the feed I would like to provide.

But it seems that I have provide "substitute" channels for the ones removed by cutting from the cable.

 

Here's an example:

People are watching serveral of the TV's in our building. For the next hour it is needed to play a DVD/VHS tape from our source. A person would go to the equipment room and push something like an A/B switch that would change the buildings tv's from cable to our source showing a DVD/VHS over all channels.

We have H1N1 type content to play and everyone needs to see it no matter what channel a tv is turned too.

[shoreviewsecurity 0]

I understand what you are trying to do but again, if your cable provider offers Telephone service and you cut away from the CATV system then you are inturrupting a life line service not to mention Internet service to the residents and or any management services depending on that connectivity to the outside world.

 

Also, you say you want this content to display on every TV on any channel. That can not be done without building a mini headend and inserting that content on ALL the channels.

 

Assuming very basic service coming into the building, no digital or telephony, this can be done but all the TV's in the building will need to be tuned a specific channel in order to watch your content.

 

What type of complex is this?? Not trying to be an alarmist. Just trying to disclose the potential issues. Sounds like a great idea in an effort to inform everyone but easier said than done I'm afraid.

[Dave109 0]

Yes, it's getting past what I can probably handle. I'm in the I.T. dept. and this is a project we are looking into. There is only basic cable service being switched.

So, it seems like a rack with an RF modulator for each channel I want to cover/reproduce. I take it would all then go into a combiner and sent on into the building for the tv's I want the content on.

I'd still like it to be simple for someone just to be able to use an A/B switch to swithc between cable and DVD/VCR being feed into all channel on the selected tv's.

I can do this with a VCR now but the TV's ahve to be on channel 4 and the ofcourse the other channels are static. Might have to settle for this. Of course, if folks didn't want to watch MRSA or H1N1, they could just turn off the TV.

I may have to look at something like digital signage on monitors placed around the building that can continually display the needed content.

I really hoped there was an rf modulator that instead of one channel is could at least do several channels. Is that what you meant by a mini headend?

[Soundy 1]

If you're in IT, how about a network-based solution? Push the video out to everyone's desktops/laptops. Or put it on an intranet page, email everyone a link, and embed some code that produces a popup they have to click when the video is done - then you can track who's watched it and who hasn't.

[shoreviewsecurity 0]

Yes, but you will need a modulator for every channel that could be possibly tuned to in the building thus a mini headend. Would not be very cost effective.

 

I still think inserting on one channel and letting all the residents know what channel that content is on would work. So it's not a must see event. Just informational??

 

So if it's only "basic" service then consider inserting on an unused channel but if you do that insure that the TV's in the building are capable of tuning to that channel. What's the highest channel on the system now?? If there is no digital in the building, pick a channel a few up from the highest and insert there. That way you will not have to worry about adjacent channel issues.

Edited October 18, 2009 by Guest

[Dave109 0]

If you're in IT, how about a network-based solution? Push the video out to everyone's desktops/laptops. Or put it on an intranet page, email everyone a link, and embed some code that produces a popup they have to click when the video is done - then you can track who's watched it and who hasn't.

 

The "audience" this is intended for only has TV's in thier locations.

We are already doing as you mentioned for the employees at the desk.

You might say it's a controlled audience that have their TV's turned off and on for them that I am trying to make this happen for.

[shoreviewsecurity 0]

OK now I think I know what you are referring to without saying it. A very "controlled" environment.

[Soundy 1]

Hmm. My next question then might by, what type of TVs are these? A lot of newer TVs have wired-remote capability for just this sort of control capability (although it's more commonly used for things like video-conferencing - switching inputs in sync with other A/V components, lighting etc.) If they're all the same brand/model, you might be able to run an IR mouse to each TV as well. Either way, when you want to run the "forced" video, you send the code to the TVs to change the channel or input as needed.

 

In fact, if you did that, and had A/V lines running to the TVs, you could probably get away without ANY modulators - just "broadcast" the serial/IR code to switch to the A/V input, and fire up your content. Better still, most newer TVs have discrete codes for POWER ON and POWER OFF, rather than a simple POWER TOGGLE command, so you can ensure all the TVs are turned on regardless of their initial state.

[Dave109 0]

I believe you understand what I'm saying.

 

So a mini headend sounds like a way of having several smaller rf modulators in a cabinet....

I was still thinking rf modulator channel 3,4,5,6,7,8,- to -98...

Hmmm... I wonder something like an emergency broadcast interupt over all the channels...

Like I said, it's not in my area. I can see some of it but I've never worked with this to this end.

[Dave109 0]

Hmm. My next question then might by, what type of TVs are these? A lot of newer TVs have wired-remote capability for just this sort of control capability (although it's more commonly used for things like video-conferencing - switching inputs in sync with other A/V components, lighting etc.) If they're all the same brand/model, you might be able to run an IR mouse to each TV as well. Either way, when you want to run the "forced" video, you send the code to the TVs to change the channel or input as needed.

 

In fact, if you did that, and had A/V lines running to the TVs, you could probably get away without ANY modulators - just "broadcast" the serial/IR code to switch to the A/V input, and fire up your content. Better still, most newer TVs have discrete codes for POWER ON and POWER OFF, rather than a simple POWER TOGGLE command, so you can ensure all the TVs are turned on regardless of their initial state.

 

 

Many of the TV's are on the low end, many are still tube w/o digital turners.

The "wired remote" looks interesting.

[Soundy 1]

"Wired remote" in this case is usually a serial port (most of the ones I've seen are standard DB9M, RS-232); the same codes that are normally sent to the remote's IR receiver are sent to that port instead. As noted, they're commonly used in installations where you want to power a TV on or off and change its settings in conjunction with other A/V components, in things like boardroom or conference room situations.

 

An "IR blaster" or "IR mouse" is just a little IR LED that's placed in front of the TV's remote receiver, and the remote codes are sent to that. Unfortunately, with a range of different brands and models of TVs, even IF they all support IR remote, most will have different codes for changing inputs or channels, which would make it very complex and tedious to set up.

[hardwired 0]

At first, this sounded pretty difficult, and it still will be, but maybe not as bad as I thought.

 

He will not need all the notch filters, just RF modulation onto all the channels used(still difficult) and a good A/B switch of some type to cut the distribution amp in the building (assuming there is only one) over to the combined RF modulated feed, off from the cable feed.

 

No notch filters necessary, because the incoming cable feed will be disconnected at the time the modulated feed will be viewed.

 

He could look at http://www.blondertongue.com/ for some heavy-duty solutions, or http://netmedia.com/modulators.html ,MM73 triple play model would give him three channels at a time, feed them into combiners, and then the A/B switch.

[rory 0]

http://www.linearcorp.com/product_detail.php?productId=225

http://www.linearcorp.com/audio_video_distribution.php

[Dave109 0]

Would you mind a simple diagram? It's always easier for me to see things that way.

 

outside cable

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split out to rdfmodulator(s)?

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modulator x 9 = 27 channels?

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combiner ( from all modulators )

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feed into building

[hardwired 0]

Video source

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Baseband video splitter

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RF Modulators

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RF Combiner

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One leg of A/B switch

 

 

Building feed

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Other leg of A/B switch

 

Output from A/B switch to building distribution

 

Hope you get the idea, I'm lousy at these ASCII drawings

[Dave109 0]

I think this will do what I need.

 

 

Video All-Call Systems VACD-12 and AB-800

Blonder Tongue

"Additionally, emergency or general announcement information can be quickly delivered with both audio and video information to each television in the school. Blonder Tongue manufactures a complete line of products for implementing a Video All-Call System. These systems provide an integrated solution of allowing one channel to override all other channels on all televisions in a school system. In order to integrate all of these components into a complete all-call system, Blonder Tongue also offers the VACD- 12 Distribution Amplifier and the AB-800 Pin Diode Switch. These two products are used to distribute the alternate audio/video program to each modulator and processor in the system. When invoked, the substitute IF program will override the normal IF programs available at each modulator and processor. Every channel in the system will be overridden with the new program."

[shoreviewsecurity 0]

Thanks for the info and good luck with your project.

[Dave109 0]

Well, after many phone calls, this isn't going to work. It's not meant to hook directly to your cable feed from the cable company or so I understand now.

I'm glad I called Blonder Tongue just to be sure.

I thought it was too good to be true.

So back to what was suggested here as that appears to be the best source of information.

I'm looking at the following:

Blonder Tongue RF modulators AMCM 860B and MICM-45C.

Now the fixed MICM-45C modular is a lot less expensive and I'm leaning that way. Any thoughts using the this one over the AMCM 860B?

Looking at 24 channels roughly.

I'm also wondering if it's possible to use TV tuners like the Zenith DTT-900 in place of the above rf modulators. I'd tune each to a different channel and still hook them all to a combiner and then into the building.....

[scorpion 0]

Could something like this work?

 

http://www.cepro.com/article/channel_vision_affinity_digital_cable_combiner_amplifier_for_digital_cable_/K11

[Dave109 0]

I went with blonder tongue with several mini-mod fixed channel modulators (MICM-45c) and two mini-mod agile channel modulators (AMCM-860).

Also with the 12 slot chassis to hold them all.

Also the blonder tongue 12 port passive combiner (ZHC-12A).

I went with coaxial switch timer from Monroe Electronics (RA157A) (automated A/B), that will turn the switch at preset times from cable to our DVD broadcast via the above setup.

Now this all sounds good but I am getting ready to test it and I have a feeling it's not that easy. What can I do if the signal from the combiner is to low or high? Could that even be a problem?