Mythbust this please.

[inachu]

Reading some whole earth catalog that was over 15 years old and there was an article how you can hookup your VCR to an antenna and broadcast your own video signal 1 or 2 miles away.


Seems a bit far fetched.

 

[PhIlLy ChEeSe]

I'd think its more then that to make it work, got a link or can you copy n paste it?

 

[inachu]

I'd think its more then that to make it work, got a link or can you copy n paste it?

Wish it was a link. I read an actual whole earth catalog book.


I found a link but not to the whole earth catalog:

http://www.instructables.com/id/Turn-your-VCR-into-an-RF-or-AV-Transmitter/

 

[Paperdoc]

On any VCR the coaxial RF output connector (the one you connect by cable to your TV's Antenna input) is sending its signal as a standard RF signal on Channel 3 or 4 (depends on how you set your VCR). So, if you then connect that VCR output to an actual over-the-air receiving antenna for a TV (specifically, one for low-band VHF channels 2 through 6, at least) you can transmit that signal in the air. Now, the output of the VCR is very low. It is, after all, designed to run a short distance over a good line to a tuner input (on the TV) designed for weak incoming signals. So, no surprise, your broadcast signal will be very weak and pick-up-able only within a short distance.

The link inachu provided suggests this weak signal can be boosted if you put a broadband cable TV amplifier in the line from VCR to antenna, and this is correct. However, it does mean that you now risk being caught broadcasting an illegal signal on public TV channels. And despite one comment in that link, this IS a public, restricted broadcast space (Channel 3 or 4), not something limited to VCR use. Your signal can interfere with licensed commercial signals on those channels and maybe adjacent channels.

By the way, that link also shows in the photos that the poster tried to construct a broadcast antenna by jamming a coat hanger wire into the VCR's output connector. That is a lousy inefficient antenna, which I'm sure contributed to the very poor quality the poster observed. Any standard TV antenna for reception, such as rabbit ears or a modest Yagi antenna, would also work as a transmission antenna, and be much better than random wire. Such receiver antennas, though, are usually quite directional, and do not send their signals out uniformly in all directions.

 

[mindless1]

Seems kind of pointless today with ready made products, streaming STBs, let alone the versatility of networking computers in general.

Anyway it's just a low level signal and the gain from an add-on amp and antenna vs the distance and interference, and of course receiver sensitivity, determines the range.

In some ways it's not so much different than hooking the headphone output jack of your phone up to a home stereo then the louder you crank it up, the further away people can hear it.

 

[WHAMPOM]

Reading some whole earth catalog that was over 15 years old and there was an article how you can hookup your VCR to an antenna and broadcast your own video signal 1 or 2 miles away.


Seems a bit far fetched.

No. That was how low power local TV was done. Camcorder to VCR, VCR to amp, amp to omni-dir antenna. You could get a twenty mile range. Big Corp TV lobbyed Congress and now we have digital. You do notice there is now nothing made that you can hook up a camera to and sends out a digital signal?

 

[TheELF]

You do notice there is now nothing made that you can hook up a camera to and sends out a digital signal?

I think I heard about something like this at one point,I think they where calling it youtube

 

[AD5MB]

yes, it would work. no, it's not legal

simple inexpensive legal solution, if the content is suitable for amateur radio:

1) get an amateur radio technician license. It's a 35 question test.
2) get a frequency agile RF modulator from eBay. ChannelPlus 5525 at $80: http://www.solarpanelstore.com/solar-power.wire.mc4_assembly.mc4_key.info.1.html
3) Set the RF modulator to channel 59, which is a standard ham radio ATV ( Amateur TV ) channel and blaze away. you can get commercially made Yagi antennas to boost the sig strength at both ends . Standard TV antennas do not increase signal strength

I have 3 ChannelPlus 5545s in my CCTV system. I can't tell you how reliable they are, because they never fail. they have all been in service for about ten years.

You can use a standard NTSC TV receiver set to cable channel 59 to receive.

 

[Paperdoc]

WHAMPOM raised an important point I had forgotten. ALL over-the-air TV broadcasting today in much of the world is being done by digital signals, most of them in the UHF bands. Few TV's these days are configured to be able to tune into older analog TV channels, although most TV's can do this. Thus, even if you do broadcast these signals, few people will stumble across them and view.

However, to do this still will be illegal because it will interfere with licensed digital broadcasts on channels 3 or 4, and possibly adjacent. Although the signals broadcast today are digitally encoded, some still use the carrier frequencies of the older Low VHF band that carried analog Channels 2 through 6.

 

[Cogman]

No. That was how low power local TV was done. Camcorder to VCR, VCR to amp, amp to omni-dir antenna. You could get a twenty mile range. Big Corp TV lobbyed Congress and now we have digital. You do notice there is now nothing made that you can hook up a camera to and sends out a digital signal?

There were a couple of reasons for the killing off of analog TV. Probably the biggest driving factor is that analog TV signals consume a lot of bandwidth and claimed low frequency bandwidth to boot (low frequency bandwidth is really valuable because it has long broadcasting ranges and penetrates practically everything). Any company doing wireless data transmission will pay top dollar for a slice of the spectrum at such a low frequency.

This bandwidth was reclaimed so that the FCC can auction it off for a pretty penny.

https://en.wikipedia.org/wiki/United_States_2008_wireless_spectrum_auction

I haven't seen what they have done with the VHF spectrum yet.