Is this possible.....
 

Is there a way to take the RF output of a video modulator, boost it, connect it to an antenna and pick it up a few feet away at the TV's antenna?

I have an RCA audio/video multi input RF modulator and right now it is connected via a coax. I would like to do away with the coax and just use the rabbit ears. I know of some that purchased an older Blonder Tongue unit from ebay to do this, but the units are quite large for what I want to do. I was thinking it shouldn't be hard to amplify the RF output enough so a connected antenna could broadcast it a few feet.

Not really. Most antenna amps don't have the output power to transmit.... There's a slim chance some cable TV head end amp might be able to do that but that's going to require research.

You need a minimum of 40dBmV to do decent transmitting especially if your antennas aren't dimples tuned for the specific channel.

IIRC some people have used Blonder Tongue MCIM modulators for compact size. There's other transmitter use capable modulators made by other brands too.

This is slightly larger than a deck of cards and will throw a signal across the room with no trouble, I have one connected to a pair of rabbit ears through a balun. https://www.ebay.com/p/812710024

This is about the same size but has much higher power output. I'm not sure if it's legal in the US, but will definitely cover your entire house. This is the 500mW version. I have the 2W. one and it will cover a neighborhood. Extremely well made. https://www.fvitrix.com/index.php?ma...ucts_id=450583

I would only need to transmit about 3 feet. Don't need too much power.

Does anyone know what is now using the channel 3 range? I don't want to interfere with something if I end up with too much power.

Channel 3 (low VHF) is still used for commercial TV broadcast in some cities. you need to consult the FCC site or a site like antennaweb.org to determine what RF channels are in use in your area. Note that a strong signal on channel 3 can cause adjacent-channel interference on channels 2 and 4.

I haven't looked at Part 15 recently, but I think it may specify field strength, not output power. If so, this will be a real problem to measure without a calibrated field strength meter and antenna.

See page 3:
https://transition.fcc.gov/Bureaus/E...3/oet63rev.pdf

I've used the older CATEL CATV head-end modulators to do in-house broadcasting, they're much cleaner than the typical VCR RF modulator and most of that head end stuff has an output greater than +10dbm and with a good Winnegard or B-T distribution amp +30dbm... a full watt. Personally I wouldn't go this high simply because one its illegal and two unintended reception by the neighbors.

Plenty of that stuff floating about from the hotels and others who have made the move to QAM digital for their internal distribution.

Make a dipole antenna, cut it for Ch3 String it up flat then match the rabbit
ears with it for length. You should get a foot or two I would guess.

73 Zeno:smoke:
LFOD !

I'm looking for about 3 to 4'. I had a Blonder Tongue that did it, but the darn thing was huge in a rack mounting enclosure. I got rid of that and have been using coax.

How about if I connected a simple pair of rabbit ears to the RF output and used another pair on the set? I don't want to go out and get a set of ears if this approach won't work.

You can get cheap rabbit ears for $6 on Amazon. If you're willing to spend $12, you'll have something for future trials if your signal is too weak on this try. (I'm guessing it will be too weak, though.)

A good distribution amp would work for driving a rabbit ears thru a balun, would cover the house.