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Cable signal scrambling method question

C

CurtisNEPA

Do you remember back in the day when you had a cable subscription and when you tuned to HBO or Cinemax, the picture is scrambled, but you can still hear the audio but with the noisy *ditditditditditdit* sound in the background? I remembered visiting my dad's friend's house years and years ago, and we were allowed to watch TV, but when I put in those said channels, I see the same scrambled video but the audio was crystal clear without the noise. That was on a big screen TV. There are some instances that when there was severe weather and the cable went out, and as the service came back on, all I remembered was that the channel was scrambled for a few seconds and then the signal was stabilized. This wasn't on any premium channels, it was on normal basic cable when that happened. The audio portion of that scrambled signal sounded like loud, creepy beeping noises with white noise in the background and the video was that of a "squiggly line", but looks different than premium TV.

Curious what kind of scrambling methods did your cable system used?
 
As a kid I remember the first cable system we had in the mid 80s, used to scramble channels where the picture is kind of wavy , almost like you want to turn the knob and tune it in. Every now and then you could make out a picture. And you could hear audio for the most part. I remember as kids we were curious about the playboy channel and stuff 😁

In 1987, when we moved to Yorba Linda, CA, the cable company there was different. The paid channels had white flashing bars and made a high pitch beeping sound. You couldn't see or hear anything. They also had A/B switches, which I had also never seen before.

(On a different note, I also remember when certain cable channels would have the touch tones before a commercial)
 
In the late 1980s/early 1990s addressable cable boxes weren't in use, at least where I grew up. The only 3 pay channels back then were HBO, Showtime and 1 other (probably Cinemax or Starz back then??). They installed a standard cable box/tuner in your home, but there were 3 cylindrical filters located up at the top at the utility pole where your cable feed split off the main line. Later, they began installing large grey plastic utility boxes on the back of everyone's home. There was a small door at the bottom left that could be accessed with a screwdriver, where one could check the cable coming into the home for signal and the connections. However in the larger part of that box, there were the cylindrical filters for the 3 pay TV channels, and that section of the grey utility box was secured by a seal, the color of which indicated which services you subscribed to, so the cable guy could verify which filters were in place vs. the service you were paying for.

I was told the reason for the grey home-mounted utility boxes was because a number of people attempted to climb the utility poles to remove the filters and were injured, and this resulted in lawsuits. Thus, the idea of placing the filters inside a secure box mounted on the home where customers didn't need to climb or work at height to remove them.
 
I have a tape somewhere that has a couple of hours of scrambled Disney Channel at the end with very loud beeping noises (scrambling, of course). The tape also has a press conference on the Tonya Harding-Nancy Kerrigan case. The taper must have forgotten to pay for the extra subscription. I also have part of the Holyfield-Stewart fight from 1993 off PPV with scrambled video and clear audio. I guess they wanted to save money and let the announcers do the talking.

DTMF tones were used on several networks in the 1980s to cut over to cable-inserted commercials - CNN, A&E, maybe TNN and Lifetime. Court TV was using audible tones up through the early-mid '00s! RTV/RetroTV as well, but we no longer have an affiliate.
 
Neel said:
As a kid I remember the first cable system we had in the mid 80s, used to scramble channels where the picture is kind of wavy , almost like you want to turn the knob and tune it in. Every now and then you could make out a picture. And you could hear audio for the most part. I remember as kids we were curious about the playboy channel and stuff 😁

In 1987, when we moved to Yorba Linda, CA, the cable company there was different. The paid channels had white flashing bars and made a high pitch beeping sound. You couldn't see or hear anything. They also had A/B switches, which I had also never seen before.

(On a different note, I also remember when certain cable channels would have the touch tones before a commercial)
Click to expand...
This is how a generation learned to watch TV sideways and squinting
 
Neel said:
In 1987, when we moved to Yorba Linda, CA, the cable company there was different. The paid channels had white flashing bars and made a high pitch beeping sound. You couldn't see or hear anything. They also had A/B switches, which I had also never seen before.
Click to expand...

I don't remember seeing those "flashing bars" when we used to have cable, it's mostly "squiggly lines". Our cable company we had was Service Electric.

As for the flashing bars, does it also have those squiggly, or wavy lines going side to side?
 
Adelphia Comm HBO, Disney if you didn't have the channel it never showed up unless it was a free preview weekend. Was until I had Cablevision where it was the weather channel it would scramble with audio every so often on HBO, Showtime, etc.
 
I remember the early days of cable and hearing the beep beep sounds on some channels. In the area we lived in the positive traps were little boxes they placed in your line just before the cable box. When the Disney Channel was added, the installers got so backed up on installs that they had you come to the office to pick up the trap to install your self. That lasted for a year as they were about to do a total rebuild of the system from a 29 channel one to 77.
 
The tones were quite prevalent with ESPN especially! 😊

We first subscribed to cable in New Britain, CT in April 1981. We had the old wired three level Jerrold click button box and fine tuning wheel. It only went up to channel 37. 14/15/16 was HBO, The Movie Channel and Escapade (after 8 pm). We had TMC for at least a year.

Several years later, we had HBO instead. Even after our system's first digital rebuild in 1993, it was still possible for all TVs on our floor to get HBO. Tuned the bedroom TV to cable 14 and it worked. 😊
 
CurtisNEPA said:
I don't remember seeing those "flashing bars" when we used to have cable, it's mostly "squiggly lines". Our cable company we had was Service Electric.

As for the flashing bars, does it also have those squiggly, or wavy lines going side to side?
Click to expand...
They were white bars that went horizonal across the screen and made a "beep beep beep" sound. Yorba Linda cable company was the only place I saw pay tv scrambled like that (and also use an A/B switch)
 
Also, sometimes switching to a scrambled channel can cause seizures to some people. Probably because of the "squiggly lines" that run vertically and colors changing?
 
DTMF tones were sent by cable networks usually three seconds ahead to signal local equipment to roll a tape and switch to local commercials. As for scrambling, the white lines and loud chirping sounds were caused by a system called a "Postive Trap". This means the subscriber had to have a trap to block that interfering signal in order to receive the channel without that interference. Negative trap was used to block the channel completely usually at the pole outside. Channels that used traps were usually low numbers, because traps perform better at lower frequencies. Other scrambling systems were usually based on "sync suppression" which prevented the tv from showing the signal. The descrambler would restore the sync information usually contained in the audio channel.
 
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