hcliff@wybbs.mi.org (Cliff Helsel) (09/21/90)
I found the following instructions in a text file on a bulletin board and wonder whether this will do what is claimed. Materials Required: Radio Shack mini-box #270-235 1/4 watt resistor, 2.2k-2.4k ohm #271-1325 75pf-100pf variable capacitor hard to find? 2 - F61a chassis type coaxial connectors RS #278-212 12" - No. 12 solid copper wire 12" - RG59 coaxial cable 1. Bare a length of No. 12 guage solid copper wire and twist around a 3/8" nail or rod to form a coil of 9 turns. Elongate coil to a length of 1 1/2" inches and form right angle bends on each end. 2. Solder the variable capacitor to the coil. It doesn't matter where you solder it, it still does the same job. The best place for it is in the center with the adjustment screw facing upward. Note: When it comes time to place the coil in box, the coil must be insulated from grounding. This can be done by crazy-gluing a piece of rubber to the bottom of the box, and securing the coil to it. 3. Tap (sp?) coil at points 2 1/2 turns from ends of coil and solder to coaxial chassis connectors, bringing tap leads through holes in chassis box. Use as little wire as possible. 4. Solder resistor to center of coil and grouond other end of resisotr to chassis box, using solder lug and small screw. 5. Drill a 1/2" diamater hold in min-box cover to permit adjustment of the variable capacitor from the outside. Inspect the device for defects in workmanship and place cover on mini-box. Tighten securely. 6. Place device in line with existing cable on either side of the converter box and connect to television set with the short piece of RG59 coaxial cable. Set television to HBO channel. 7. Using a plastic screwdriver (non-metallic) adjust the variable capacitor until picture tunes in. Sit back, relax, and enjoy!!! ------------------------------------ If it will do what is claimed would anyone be willing to answer some questions about the construction of this device. Cliff Helsel hcliff@wybbs.mi.org or hcliff@wybbs.UUCP
jws@thumper.mlb.semi.harris.com (James W. Swonger) (09/21/90)
This looks like the type for descrambling the most primitive type of pay-TV - you know, like the HBO channel that sits by itself on channel 5. This lonesome channel is made unviewable by overlaying another signal very close to it. The cable company puts a trap in the line when you pay. Then you can get that one channel without a new box. The other channels, which get grouped together in a pay-channel block, are doctored in other ways which require more sophistication to restore. I suspect that a simple 1-stage filter might leave something to be desired. A multi-stage one would probably give better results. You should NOTE: Our local cable monopoly, and probably most of the others, is having a big push to catch people who are (Gasp!) "stealing" cable services. It is easy for the cable dudes to find a trap such as the one described by sending the signal up the line and seeing if there's any funny characteristics at that frequency. Question: Does anybody know whether the cable box makers put any sort of ID marker (e.g. a notch or resonance at some frequency) at the box input to tell if one of their boxes is on the line? I have had this suspicion for some time but have not seen anything one way or the other. If you are going to be a naughty boy and/or girl, you should be sure to isolate whatever you are doing from the cable. Buy a distribution amplifier (not just a splitter, something which doesn't pass signal backwards) and put it in line where the cable enters your house. The idea is to only let the cable see a straight 75-ohm load, like you have one TV hooked up. Anything on the other side should be made invisible to prying eyes/ears/test equipment. Not that I would advocate illegal acts.
wolfgang@wsrcc (Wolfgang S. Rupprecht) (09/21/90)
hcliff@wybbs.mi.org (Cliff Helsel) writes: >I found the following instructions in a text file on a bulletin board and >wonder whether this will do what is claimed. >Radio Shack mini-box #270-235 >1/4 watt resistor, 2.2k-2.4k ohm #271-1325 >75pf-100pf variable capacitor hard to find? >2 - F61a chassis type coaxial connectors RS #278-212 >12" - No. 12 solid copper wire >12" - RG59 coaxial cable In a word; no. It might be a good tv *scrambler* though. -wolfgang -- Wolfgang Rupprecht uunet!{nancy,usaos,media!ka3ovk}!wsrcc!wolfgang Snail Mail Address: Box 6524, Alexandria, VA 22306-0524
depolo@eniac.seas.upenn.edu (Jeff DePolo) (09/21/90)
In article <1990Sep21.125256.16206@mlb.semi.harris.com> jws@thumper.mlb.semi.harris.com (James W. Swonger) writes: > > This looks like the type for descrambling the most primitive type of >pay-TV - you know, like the HBO channel that sits by itself on channel 5. >This lonesome channel is made unviewable by overlaying another signal very >close to it. The cable company puts a trap in the line when you pay. Then >you can get that one channel without a new box. Remember the old HBO systems that used UHF frequency broadcasting and when you paid for the service, they installed a UHF antenna (sometimes a corner reflector or small dish) and a receiver? Would it be illegal to receive this? The way I interpret the laws, if it's in the air, with the exception of transmissions covered by the nasty ECPA, it should be legal to receive said transmissions. Is this correct? --- Jeff -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jeff DePolo N3HBZ Twisted Pair: (215) 386-7199 depolo@eniac.seas.upenn.edu RF: 146.685- 442.70+ 144.455s (Philadelphia) University of Pennsylvania Carrier Pigeon: 420 S. 42nd St. Phila PA 19104
fmgst@unix.cis.pitt.edu (Filip Gieszczykiewicz) (09/22/90)
Greetings. (Concerning the cable company being able to detect "hackers" by sending signals up to your house...) What would they say if, when they came to your house, that the cable came through the wall and went right next to a huge AC motor. After all, if it was ON, there would be no question as to what was causing the change in freq. response :-) Or the variations of the above.... Take care. (Hey! it's 5:37 AM....) -- _______________________________________________________________________________ "The Force will be with you, always." It _is_ with me and has been for 10 years Filip Gieszczykiewicz "A man without a dream is like a fish without water." FMGST@PITTVMS or fmgst@unix.cis.pitt.edu "My ideas. ALL MINE!!"
me (09/24/90)
In article <1990Sep21.125256.16206@mlb.semi.harris.com>, jws@thumper.mlb.semi.harris.com (James W. Swonger) writes... > > Question: Does anybody know whether the cable box makers put any sort of >ID marker (e.g. a notch or resonance at some frequency) at the box input to >tell if one of their boxes is on the line? I have had this suspicion for some >time but have not seen anything one way or the other. Yes they do. In my neighborhood, they use crimp-on colored plastic tags indicating the authorized service. Trucks haunt the neighborhood with a vertical dipole (approx 135 Mhz, it looks like) "listening" .... perhaps for the LO of a unauthorized cable controlbox. In my experience, (9 yrs?) there is little to no risk in installing an in - line filter to notch out the HBO-jamming signal.
downin@dtoa1.dt.navy.mil (Downin) (09/24/90)
With my cable company I get all the premium channels on my TV (only problem is they are scrambled). The picture appears wavy and the colors are slightly off. The sound comes in crystal clear. When I fine tune the set I can usually get a VERY snowy and slightly wavy picture to come in (black & white only). Also, without the fine tuning I can hear a high pitched whine like an oscillator running off frequency. I suspect that all that has been done is the sync signals have been screwed with in some way. This would explain the wavy picture, off colors and oscillator whine. Is it possible that it might be something else though? And does anyone know where I can get schematics forta device that would completely re-construct the sync signals? Dave Downin downin
brown@vidiot.UUCP (Vidiot) (09/25/90)
In article <477@wybbs.mi.org> hcliff@wybbs.mi.org (Cliff Helsel) writes:
<I found the following instructions in a text file on a bulletin board and
<wonder whether this will do what is claimed.
This only works on systems that use carrier interference, ie, a signal that
is equal to carrier heighth is added about 2.5 MHz above the carrier.
What this does is cause the AGC of the TV's tuner to believe that the signal
is real strong, so it buries the signal in the mud by reducing the signal gain.
What this circuit does is become a notch filter for this extra carrier.
The version given is very broad and needs to be changed to a fixed capacitor
within the notch needed for the particular channel and a very small variable
cap to fine tune it. Also needed is a variable pot for the `Q' adjustment.
The whole idea is very touchy and needs to be re-adjusted every couple of
weeks.
This method will not work for active methods of scrambling. This is a passive
method only.
--
harvard\ att!nicmad\ spool.cs.wisc.edu!astroatc!vidiot!brown
Vidiot ucbvax!uwvax..........!astroatc!vidiot!brown
rutgers/ decvax!nicmad/ INET:<@spool.cs.wisc.edu,@astroatc:brown@vidiot>dgc@euphemia.math.ucla.edu (David G. Cantor) (09/25/90)
Readers interested in cable TV descramblers should read the classified ads in the widely distributed magazine Radio-Electronics. There are 30 or so companies advertising these devices. They seem to carry all standard brands, e.g., Scientific Atlantic, Jerrold, Zenith, Tocom, etc. The business appears to be highly competitive and, given the completely open advertising, probably legal. The only catch appears to be that none of these companies will sell within the State within which they are located. dgc David G. Cantor Department of Mathematics University of California at Los Angeles Internet: dgc@math.ucla.edu
alex@bilver.UUCP (Alex Matulich) (09/26/90)
In article <3611@oasys.dt.navy.mil> downin@dtoa1.dt.navy.mil (Dave Downin) writes: >With my cable company I get all the premium channels on my TV (only >problem is they are scrambled). The picture appears wavy and the colors .... > I suspect >that all that has been done is the sync signals have been screwed with The way I understand it, the sync signal is actually inverted. Yes, circuits can be built to restore the sync, but it's not something trivial. -- _ |__ Alex Matulich (alex@bilver.UUCP) /(+__> Unicorn Research Corp, 4621 N Landmark Dr, Orlando, FL 32817 //| \ UUCP: ...uunet!tarpit!bilver!alex ///__) bitnet: IN%"bilver!alex@uunet.uu.net"
rbrink@hubcap.clemson.edu (Rick Brink) (09/29/90)
From article <3611@oasys.dt.navy.mil>, by downin@dtoa1.dt.navy.mil (Downin): > Is it possible that it might be something else though? And > does anyone know where I can get schematics forta device that would > completely re-construct the sync signals? > May 1990 of "Radio-Electronics" has inst. & sch. for a sync. restorer.
nx00699@dsac.dla.mil (Gene McManus) (10/03/90)
From article <10676@hubcap.clemson.edu>, by rbrink@hubcap.clemson.edu (Rick Brink): > From article <3611@oasys.dt.navy.mil>, by downin@dtoa1.dt.navy.mil (Downin): > May 1990 of "Radio-Electronics" has inst. & sch. for a sync. restorer. If anybody has a spare copy of this issue of R & E, I'd be interested in buying it. Gene /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ ( Gene McManus @ DLA Systems Automation Center, DSAC-X ) ( Columbus, OH 43215 (614) 238-9403, Autovon 850- ) (____________________________________________________________________) ( Internet: gmcmanus@dsac.dla.mil (131.78.1.1) ) ( UUCP: {uunet!gould,cbosgd!osu-cis}!dsacg1!gmcmanus ) \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
rusty@steelmill.cs.umd.edu (Rusty Haddock) (10/05/90)
In article <2135@dsac.dla.mil> nx00699@dsac.dla.mil (Gene McManus) writes: >From article <10676@hubcap.clemson.edu>, by rbrink@hubcap.clemson.edu (Rick Brink): >> From article <3611@oasys.dt.navy.mil>, by downin@dtoa1.dt.navy.mil (Downin): > > >> May 1990 of "Radio-Electronics" has inst. & sch. for a sync. restorer. > >If anybody has a spare copy of this issue of R & E, I'd be interested >in buying it. Check your local public library for back issues possibly using their copying machine to dup' the article. If you can't find it let me know and I'll dup' the copy I have. BTW, has anyone BUILT this project and got it working? A couple of us here at UMd are about to order the P.C. boards and components from the P.O. Box in the article. [I track the company(?) down via the phone today so they're still around :-] We'd like to use it for cleaning up VCR output that's going to our frame-grabbers (of various makes). Thanks! -Rusty- -- Rusty Haddock DOMAIN: rusty@mimsy.cs.umd.edu Computer Science Department PATH: {uunet,rutgers}!mimsy!rusty University of Maryland "IBM sucks silicon!" College Park, Maryland 20742 -- PC Banana Jr,"Bloom County"
ray@ole.UUCP (Ray Berry) (10/05/90)
nx00699@dsac.dla.mil (Gene McManus) writes: >From article <10676@hubcap.clemson.edu>, by rbrink@hubcap.clemson.edu (Rick Brink): >> From article <3611@oasys.dt.navy.mil>, by downin@dtoa1.dt.navy.mil (Downin): >> May 1990 of "Radio-Electronics" has inst. & sch. for a sync. restorer. I have one of these kits I'd be willing to part with at a moderate dis- count (~$80) from the new price (unassembled, as received from vendor). -- Ray Berry kb7ht uucp: ...ole!ray CIS: 73407,3152 /* "inquire within" */
bill@videovax.tv.tek.com (William K. McFadden) (10/06/90)
In article <26851@mimsy.umd.edu> rusty@steelmill.cs.umd.edu (Rusty Haddock) writes:
-> >> From article <3611@oasys.dt.navy.mil>, by downin@dtoa1.dt.navy.mil (Downin):
-> >> May 1990 of "Radio-Electronics" has inst. & sch. for a sync. restorer.
->BTW, has anyone BUILT this project and got it working?
A friend of mine who repairs TVs and VCRs for a living built one. He says it
works pretty well, but can be a bit finicky to set when you change channels.
Overall, he says it's a win.
--
Bill McFadden Tektronix, Inc. P.O. Box 500 MS 58-639 Beaverton, OR 97077
bill@videovax.tv.tek.com, {hplabs,uw-beaver,decvax}!tektronix!videovax!bill
Phone: (503) 627-6920 "The biggest difference between developing a missle
component and a toy is the 'cost constraint.'" -- John Anderson, Engineer, TI