Audio/Video RF Modulator(s)

Search on these forums helped a good bit, but I want to make sure I got this right.
I see 2 types of these devices. Cheap channel 3 & 4 ones and those that let you select the channel into the triple digits.

I would like to be able to watch TV and see who is at the front door and the driveway.
“If” these devices let all the other channels pass threw and they ONLY add an unused channel, then the cheap way sounds like to buy 2 of the cheap 3 & 4 channel modulators. The others would only be good if you wanted to go beyond 3 & 4.

So, before I buy 2 cheap modulators, I wanted to make sure that my perception of these devices is right.

Details:
Aux1 & Aux 2 are already being used.
The PICOLO Junior 4 Security Card has no output.
The only way I know to get a signal is to split off the camera cable.

Also some one here said you need a splitter before the DVR recorder that has 0 ohms resistance. I never heard of this one … splitter yes, bi-passing the resistor or whatever gives it the ohms rating …no.

Thanks for tips and/or validation

In the old days it was very easy, but now adays with digital and HD signals it gets a little harder.

For a simple circuit you need an amplifier that is adjustable. When you mix the cable signal, and your modulated signal you can move the cable signal up, or down, and you can move your modulator signal up, and down.

The idea is to have a balanced mix of both signals. If the cable sig is to high then your modulated video will look off, or vice versa.

If you loop out of a DVR, or a multiplexor then on a cheap bid job this is fine, but if this is a high end job, or they are paying top dollar then you will want something like this:

http://www.radioshack.com/product/index.jsp?productId=2103065&cp=2032057.2032187.2032188.2032195&parentPage=family


If you can run separate wires to the TV/TVS then you can hook it up to a separate video input of the TV, or you can use something like this:


http://www.radioshack.com/product/index.jsp?productId=2286098&cp=2032057.2032187.2032188.2032195&parentPage=family

Check out the affinitycut.pdf link. This is really great as you do not have to run more wiring if you can get to the TV cable up in the attic!



CHANNELVISION:

http://www.channelvision.com/


Affinity Digital Cable Combiner

http://www.channelvision.com/index/15/25

http://www.channelvision.com/pdf/flyers/affinitycut.pdf

http://www.channelvision.com/index/5


Modulators
http://www.channelvision.com/index/47

Filters
http://www.channelvision.com/index/56



GUIDES:

Diagrams and Layouts
http://www.channelvision.com/pdf/support/guide/diagramsLayouts.pdf

Filters and Digital Cable Support Guide
http://www.channelvision.com/pdf/support/guide/filters_and_digitalcable.pdf

Channel Vision Networking Guides:

Advanced Data Training
http://www.channelvision.com/pdf/support/guide/AdvancedDataTraining.pdf

Basic Data Training
http://www.channelvision.com/pdf/support/guide/BasicDataTraining.pdf

I'm doing the same thing and have found it's a lot more convenient to have a separate monitor for the CCTV, if you have the space near your TV.

Perhaps a TV-out video card for your computer and a cheap color TV. Might also be less expensive than the video splitter and modulator path.

Cheapest solution of all, just tap off the camera video and run it to the aux on your VCR if avail, and accept the darker image :o

Thanks for the replies/information

Kiwi
I will look to see if the DVD/VCR has an auxiliary input since the TV is used up. I was surprised that the combination DVD/VCR required 2 inputs into the TV. I thought it was a bad unit till the directions were used. Lol! That would get 1 of the 2 camera’s working the easy way.

Scorpion
Wow, that's some links to review. Do I get a certificate if I study them all? It looks like it's been well thought out to handle this rather generic question. It does make me think that I should be thinking of the future. I can't see digital and/or HD right now, but who knows 5-10 years from know. Thanks and I’ll try and make some time to go threw the list.

Being able to flip from TV to CCTV for 2 cameras is not a high priority, just a cool feature should it be fairly cheap and easy to do.