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Introduction The difference between cable TV and regular TV can be seen in cable TV's "official" name, Community Antenna Television (CATV). Basically, with CATV, the cable company installs a TV antenna, and a satellite dish at a good receiving location somewhere (they call this place a "head-end"), and then re-transmits the TV signals over cable to customers' homes and businesses. CATV systems use frequencies between 108-400 Mhz. to send their extra channels through the system. The mid-band (channels 14-22) is between 108-174 Mhz., super-band (23-36) is between 200-290 and hyper-band (37-53) is between 290-400 Mh. (These ranges are approximate.) To keep the CATV signals from interfering with the regular services on those frequencies. the cable company must keep leakage from their system down to an absolute minimum. This is easier said than done, and no matter how hard they try, CATV systems still leak to some extent, however minimal it may be. With equipment available from your local Radio
Shack along with your TV, you can pick up low-level CATV signal leakage
and get free CATV service without having to pay an installation fee or
monthly service charges. This is all perfectly legal because you (currently)
have the right to receive radio signals that come onto your domain, and
in all reality the cable TV company shouldn't be letting these signals
leak out of their system to begin with. When attempting this you should
be aware that if your cable TV company is competent, you might not find
an area in your neighborhood's outside plant that has enough leakage to
get a good signal. Also, the way the government has been acting lately,
one never knows when they might decide people who experiment with low-level
RF signal reception are a threat to society. If such a thing does occur,
make the necessary preparations before one of those UH-60 Blackhawks full
of men with MP5SD3s lands on your lawn to bring you into "protective custody".
How to Do It: Your wireless CATV reception station will need the following:
module that mounts near the antenna and a remote power supply. The two piece models offer better amplification as they amplify the signal before it gets noise from going through the coax. channels (optional) transformer if your TV doesn't have a 75 Ohm antenna input
The system is put together as follows: ANTENNA | AMP | AMP CABLE +----POWER----CONV.---TV SUPPLY (If 2 pc. AMP)
CABLE ---CONV.---DESCRAMB----TVOnce you have your system put together you have to find a leak to receive off of. The cable companies find leaks by driving down the road with a field strength meter. You can do this by walking under the cable and stopping where you see a peak on the meter. You can get a field strength meter for under $50 at Radio Shack. However, unless you use a tuned field strength meter you will also register any strong RF source. If you have a portable TV such as a Sony Watchman, you can tune to a channel that you normally won't receive and walk around until you get reception. On a side note, many of those portable TVs that use an analog tuning dial (as opposed to a channel selector knob) often are able to receive mid-band cable channels without a converter box. (The Sony Watchman Model FD-10A can.) To check if your portable TV can do this, examine the TV's VHF (Ch. 2-13) tuning selector. The mid-band capable TV's have only 1 band for VHF selection. To get mid-band with these TV's, simply tune between channels 6 and 7. You will also be able to pick up various types of voice commo from 88-174 Mhz, although the selectivity and sensitivity on portable TV's suck for picking up narrow-band FM voice. You might fare better getting in some of the stronger FM broadcast stations on 88-108 though. When looking around for a good CATV leak, check
under junction boxes where the main line is tapped to run cable drops to
subscribers. They often degrade from being exposed to the elements. Also
check around the homes of neighbors who you feel might have added extra
CATV extensions to their houses wiring plant. If they have an antenna on
their roof, then chances are they took the wiring plant that was hooked
up to their antenna, and hooked it up to the cable system. The cable company
generally uses good quality (expensive)
Once you've found a leak, aim your antenna at
it. You should then be receiving free cable TV. The reception may not be
perfect, but what do you expect for nothing? To get better reception, try
one or more of the
insulator material is the important part, as it is needed to prevent you from accidently shorting out your neighbors cable line. ---======================================== | ^-solder here ^-magnet wire |<-apply insulating material | ^-leave tip cleanWhen that's done take assembly and crazy glue over to your neighbor that has cable TV. Find a nice run of coax and push the pin in. Make sure the tip has good contact with the center conductor of the coax. Then unroll the magnet wire and crazy glue it to the coax in a way that it won't be noticeable. What you just did was add an antenna to your neighbors
cable. You will now be able to enjoy the use of your wireless cable TV
setup. The main problem with this setup is that the resulting "leak" will
most assuredly be
Chapter 2: How to Piss Off Your Cable Company and Give Your Neighbors Free Cable TV Radio Shack sells a device which will enable you to do just that. It will also let you use any standard TV for cable reception without having to purchase separate converters for each TV, or run coax. Go to R.S. and pick up a Model 15-1281 Cable TV Block Converter. This handy little device will take your mid and super band channels and convert them to UHF TV broadcast band frequencies. Hook it up to your cable system, and attach a good UHF TV antenna to the "TO UHF" f-connector. +-------------------+ ! RS 15-1281 ! ! ! ! CABLE TO TO ! ! IN VHF UHF ! ! * * * ! +---!------------!--+ To Cable ! ! To UHF System------+ +------ Antenna
It is important that you use a good high gain antenna or you will not get any range. What you are doing is taking the cable channels 14-36 and retransmitting them over the normal UHF TV channels. This way, any non-cable compatible TV can receive them. The range isn't too great though. Expect about 300 feet or so under ideal conditions. Antenna type, height, placement, and the receiver set-up will have a lot to do in determining your range. There's a lot of possibilities for the experimenter here. Optionally, you might also want to contemplate adding a small 1-5 watt amplifier to the UHF output (Get the info from The Motorola RF Devices Manual, available for free from Motorola. Call your local rep. for info.) |