Home NTSC Transmitter
 

I know this subject has been brought up before, but for some reason I can't find it in while searching the site. Does anyone know if anyone makes low power NTSC transmitters for home use? All I want to do is to transmit from upstairs to downstairs on an unused normal TV channel at very low power.

David

This adequately does room-to-room UHF:
http://www.audiokarma.org/forums/sho...08#post1925308

The apartment amp discussed a few posts later could be made to do VHF.

This had limited success, your mileage may vary:
http://www.audiokarma.org/forums/sho...ghlight=Ramsey

Easier to build than that (and without any FCC worries) would be a device that converts ATSC to NTSC and can re-transmit them via 75ohm cable.

All of my sets are hard-wired to my outdoor antenna. The antenna comes into the basement and then gets split to about 5 different locations. It would be nice to simply add a converter which would constantly be putting out about the 15-or-so ATSC signals we have, plus the worthwhile digital side channels on unused dial space. (Currently, that's just RTN, lol)

I even drew this diagram for an electronically inclined friend at work and told him to build it for me!

http://img.photobucket.com/albums/v6...1211192327.jpg

I built my own, albeit constrained to channel 3 or 4. Basically, it's an RF modulator capacitively coupled to a 2-Meter amp. Not sure of the output, but rabbit ears produce a clean picture on the set. Ramsey kits makes a 2 meter amp - the RF modulator is an early Astec (snipped from a junk VIC-20 computer) Modulator and amp are powered by a 6V wall wart.

Aw hell, for 40 bucks, you too can build your own:

http://www.ramseyelectronics.com/cgi...ction&key=TV6C


Cheers,

Another Ramsey
 

Ramsey also shows this little...very little...module. It is capable of RF to cable channel 59 with audio/video.

http://www.ramseyelectronics.com/cgi...tion&key=C2000

A grand 20mw. They have a higher power 100mw unit...video only. Would this transmit to an antenna and then to a cable ready VHS (which I save for the tuner) in the cable mode? I would feed it with a dedicated converter box.

I have visions of it in front of a tabletop bowtie or loop feeding everything.

And is the cable channel 59 a ham frequency with black helicopters circling above me looking for my pirate station?

Dave A

No audio. "Perfect video only transmission..."

I built one... Piece of s**t...

Oh it worked... for all of 7 feet... Could only get a clear picture by setting it right next to the antenna, and it didn't go to Channel 6, or even Channel 5...

Ramsey is not known for quality kits... :thumbsdn:

You got that right. I built their "better" AM transmitter so I could broadcast to my tube radios. Hum in audio, poor fidelity, poor range. Just not a good experience. I thought I'd done something wrong; but, my research shows that it was them and not me.

What would be a simple way to amplify the RF output of a VCR? Could I build or buy something cheap to do that?

You do need a linear amplifier, so one thing that will usually not work
is an amplifier designed as a booster for FM 2-way radios. I don't believe
that such a product is commercially available, in view of the facts that
it could officially be used only by a TV broadcaster.

The need for linearity arises from the AM nature of the video signal
(actually VSB, but still needing amplitude linearity).

P. S.:

A cable TV booster could be the thing, but I don't know the power output
level of such a beast. Other ideas?

Does the Nippon America UHF transmitter work, or is another one of those, put it beside the set and it migjht receive something?

David

Carmine-

There is a kit company that already sells exactly what you have described, in the right half of your "converter" block:

http://www.northcountryradio.com/Kitpages/vmstr.htm

I have built one or two of their amateur-TV kits, and had no trouble making it work properly as described.