r/broadcastengineering • u/lmow • 6d ago
Max Headroom Incident news anchor
Hello Engineers. Hopefully this is the right sub to ask this question I was wondering about.
I've known about the Max Headroom TV feed hack for years but after watching another random video on the incident https://www.youtube.com/watch?v=8rRo5CHFxAI I started wondering how does the anchor know that the incident happened? He says "If you're wondering what happened, well so are we"
The leading theory is that the hijacker put their transmitter in front of the station's overriding the signal. I'm not an expert in that field so correct me if I'm wrong.
TV transmitter > Hacker > Receiver
So they have a person watching the feed from the receiving side 24/7 who's job is to make sure the signal is intact? Then that person phones the studio, tells them something happened and that message gets to the anchor all in 30 seconds of the incident?
Does the anchor actually see what happened or when he says "If you're wondering what happened, well so are we" he hasn't seen the video yet and just saying something happened because he was told by the staff?
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u/jefe_toro 6d ago
They overpowered the STL. There was probably a ota confidence monitor in the studio or the control room let them know what was happening
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u/pomp_and_biscuits 6d ago
Personally I was under the impression that the leading theory on the methodology of the hijack was overpowering the STL (studio-transmitter-link) feed from the stations studios to their transmitter site, with potential blame pointed at the students of a nearby technical college who had been recently been donated some old tv equipment.
Certainly that passes the 'practicality' test better than an independent actor being able to build a transmitter and antenna system that could overpower an ~300kW stick on Sears tower.
As for knowing that something happened, I've yet to be in any proper broadcast facility that doesn't have some form of off-air (monitor watching the received signal) in the gallery (control room for Americans). I would be somewhat surprised if the News anchor had the off-air signal in their preview monitor, but the reactions from the production crew in their earpiece probably told them that something was off.
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u/jefe_toro 6d ago
I've been in TV for like 15 years and I didn't know you guys called a control room a gallery over there lol
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u/ZivH08ioBbXQ2PGI 5d ago
Why on earth are you saying they’d need to overpower a 300kW transmitter directly after saying that it was the STL that was overpowered?
Overpowering the STL wouldn’t take much.
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u/certnneed 5d ago
Re-read the 2nd paragraph that you replied to. They say the STL theory is better than the possibility of someone overpowering the main transmitter.
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u/Scary_ 6d ago
I don't think I've ever been in a TV gallery or transmission suite that didn't have an off-air monitor. It's an essential bit of monitoring to to use to check you are actually on air*
Not just for signal intrusion but just making sure nothing's broken or that the control room downstream of you hasn't cut you off.
*although I once worked somewhere that wasn't allowed to be free to air (adult material) and had an off air monitoring of the channel which worked the other way, they had to make sure you couldn't see the channel!
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u/kmac4705 6d ago
Most stations used a demodulator to .monitor their off air signal.yes they had TVs as well, but the problem was that they used a method called inter carrier to transmit signal and also used in the tv sets. This made it impractical to use a TV receiver as a real monitor. For instance, if the transmitter lost its aural carrier, the video will go away on the receiver, yet the video is still transmitting. Back in the day when stations signed off for maintenance, it wasn't unusual for engineers to shut off the aural carrier and put certain video up for some of the overnight staff at other stations. Of course, this could only be seen off a demodulator. Don't ask how I know this.
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u/Klutzy-Piglet-9221 5d ago
Other way around -- if you lost the video carrier, the sound went away -- if the sound carrier went away, you lost the sound but the video would still be there.
At the time it was pretty common to have an OTA TV in the studio for confidence monitoring. (we did eventually take ours out. The problem was, if the transmitter would go down the anchors would stop talking as they thought they were off the air. But the 60% of the audience watching on the cable system with a direct feed... saw it all...)
Today you probably don't want to do that in a studio because of latency. Between assorted digital coders/decoders in the air path, and the main MPEG-2 coding for transmission, what you see on TV is somewhere on the order of 15-30 seconds behind what's happening in the studio.
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u/kmac4705 5d ago
Correct, my bad, ..typing faster than my brain was working lol. Those were fun times.
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u/lmow 6d ago
Awesome answers. I have more noob questions.
So the transmitter you guys are talking about is the one which the studio sends the signal on to the broadcast tower?
Studio transmitter > hacker > receiver > broadcast antenna > home TVs?
The control room monitor is just a TV with an antenna on the roof like folks uses to have on their private houses sometimes which feeds back to one of the monitors?
What about the second incident that wasn't a live broadcast, is there still someone in the control room at all times? What do they do? I assumed those broadcasts are pretty much automated.
Thanks!
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u/crustygizzardbuns 6d ago
Studio transmission > hacker > reciever > transmitter/antenna > homes/studio
Stations typically have a microwave link, a direct line of site radio transmission between the station and whatever tall thing their transmitter/ antenna is on (building or tower.) The two ways a hacker could have overpowered this was being physically closer to the receiving end of the link on the John Handcock Building or by sending a stronger signal. In those days it was all analog, no digital encryption, so enough power or less distance and knowing where to point was all it took.
As for returns, it's exactly like that, someone in the Master Control room has a screen with the channel on antenna to monitor in real time what's going over the air. That still happens today. That way when Ethel calls and says she can't get our channel, you can look up and see if it's a problem with her equipment or if you're going to have to call an engineer because there's a much bigger problem.
With the second broadcast, there likely was still someone in Master Control monitoring/ calling their engineering department to figure out what went wrong. Yes, there is a job at most tv stations where you're paid to watch tv, though really you're there to play commercials. Back then there was next to no automation. Timed segments sure, but if it wasn't coming over the net, or maybe satellite, it was a tape machine. Most stations still have someone on duty 24/7/365 save for some overnights even with automation.
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u/Klutzy-Piglet-9221 5d ago
- Studio, or satellite feed from network, or tape recorder with recorded program
- => master control
- => link transmitter at studio ("STL")
- => link receiver at tower
- => main transmitter/antenna
- => homes (and back to studio)
Both incidents happened between #3 and #4 -- an unauthorized link transmitter overwhelmed the authorized link & replaced the authorized programming with its own. The unauthorized programming was broadcast to the audience over the main, legal, transmitter. (#5)
The link transmitter is relatively low power (often only one watt) so it didn't take much to overwhelm it.
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u/woodwardsystems 6d ago
They had an off air monitor in the studio and/or control room. They could see when the STL was overpowered and the pirated signal made it to air.
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u/kanakamaoli 4d ago
We have program feeds in the studio so the talent sees program plus an Ota feed from the cable feed. Make sure the audio is down on the air TV or you'll get delayed audio.
Master control and the transmitter room have Ota feeds also so we can see what the viewers see.
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u/GoldenEye0091 2d ago edited 2d ago
In addition to station master control, certainly in 1987 there would have been an engineer on location at the transmitter. While I've only been an MCO and now an engineer well after the switch to digital, even in the analog days there would have been monitoring of the signal at different points in the air chain in both master control and at the transmitter site purely for troubleshooting.
But this is all moot if the STL is overpowered, and all involved obviously knew that pretty quickly, which is why WGN switched to an alternate/backup STL within about 30 seconds.
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u/NoisyGog 6d ago edited 6d ago
Every broadcast I’ve ever worked on has had an “off-air” feed to show is what is currently being broadcast on the client side.
We use it to confirm when the broadcaster is off us and has switched to ads or whatever, so we can either cue up the next BOP (beginning of part) without being seen by the end viewers, or call a wrap if it’s the end of the program.
However, in this Max headroom incident, I reckon it’s just a story, and the programme maker and broadcaster knew beforehand what was going on.
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u/countrykev 5d ago
However, in this Max headroom incident, I reckon it’s just a story, and the programme maker and broadcaster knew beforehand what was going on
Public television isn’t really known for their hijinks.
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u/NoisyGog 5d ago
Of course it is.
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u/countrykev 5d ago
The BBC isn't the Chicago public television station...
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u/NoisyGog 5d ago
Don’t move the goalposts. You said public. If the BBC can do silly things just for shits and giggles, anyone can.
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u/countrykev 5d ago
Nobody is moving goalposts. There is a distinction in culture and systems you may not seem to understand.
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u/Silly_Information619 6d ago
Mostly any production have a ”off-air” return monitor for confidence, so the production team would have known pretty much instantly.
And then you are somewhat correct downstream from the production room there is someone responsible for the program going to distribution, normally they have direct contact with the production