3ALARM TECHNOLOGY
In the world of anti-theft systems there is a common misconception: many believe that having a good jammer is enough to become invisible to any security system. Reality is more complex. A jammer is a tool that works with the gates (pedestals), disrupting their detection logic. But what happens when your opponent is not the gates but the tag itself, attached to the item?
This is where 3-Alarm technology comes in. This is a class of devices that don’t just sit passively on the merchandise — they have their own active electronics that can “listen” to the environment and trigger an alarm on their own.
Evolution of protection: from 1 to 3
To understand how to deal with them, you need to clearly separate tag types by what they do:
1-Alarm (Standard):
! The classic passive tag.
- No battery inside. It only acts as a signal reflector. If you walk through the gates, the gates “see” the tag and beep themselves. If you cut the pin/tether - nothing happens.
2-Alarm (Tamper protection):
! The tag has a battery and a protection loop. This covers almost all spider tags, cable tags, and the like:
- Function: If the gates see the tag - the gates beep.
- Bonus: If you cut the tether (break the loop) - the tag itself starts beeping loudly. But if you take it out in a shielded bag or with a jammer on, it stays silent (because it doesn’t react to the gate field).
3-Alarm (Active protection):
! The peak of retailer paranoia:
- Function 1: Gates see the tag - gates beep.
- Function 2: You cut the cable - the tag beeps.
- Function 3 (The critical one): The tag has a built-in receiver. If it “hears” the specific gate signal (AM or RF), it triggers its own siren.
The problem
A jammer suppresses the gates’ receiver, but it cannot “turn off” the signal the gates transmit. A 3-Alarm tag, when close to the pedestals, picks up their strong emission and starts screaming — even if the gates themselves are “blinded” by the jammer.
How it works technically
Inside a 3-Alarm tag (whether it’s a spider or a hard tag) there is not just a coil with a ferrite core, but also an analyzer chip, constantly powered by the battery.
The electronics continuously scan the air via their own antenna. The analyzer’s firmware looks for specific patterns — pulse timings typical of EAS systems (58 kHz for AM or 8.2 MHz for RF). As soon as the tag recognises this “signature” (when you get close to the gates), it activates the built-in piezo and LED.
Main manufacturers:
- Alpha Security: Market leader. They usually mark their products with the “3alarm” logo. Often seen as spider tags and CableLok-style tags.
- Century and WG (4alarm): Use similar tech, but often without any visible marking, which makes identification harder.
Important nuance: Tag behaviour after opening (removal) can differ. With Alpha Security and Century, the 3-Alarm function usually turns off when the lock is opened. On some other models (especially older or special spider tags) the electronics can stay active even when the tag is open.
Countermeasures: Diagnostics and bypass methods
Because telling 3-Alarm from 2-Alarm by eye is often difficult (especially with brands that don’t mark them), we’ve developed several approaches.
1. Electronic diagnostics (Option on our devices)
We built “Gate signal simulation” into our units.
Idea: In a safe spot (fitting room or back of the store) you enable this mode on the jammer and hold it near the suspicious tag.
Result: The jammer outputs a weak but accurate gate-style signal pattern. If the tag has 3-Alarm, it will “hear” it and start beeping (or flashing) in your hand.
Conclusion: If the tag reacted to the simulation — you must not walk through the gates with it even with the jammer on. If there was no reaction — you’re clear.
2. Physics vs electronics (Magnetic saturation)
This method relies on the physics of ferrite and works when you don’t want to (or can’t) remove the tag but really want to take the item out.
- Theory: The tag’s antenna is wound on a ferrite rod. Ferrite can amplify the signal, but only up to a certain saturation limit. If you put it in a strong magnetic field, the ferrite loses that property — it goes “blind”.
- Practice: You need a strong magnetic detacher. If you hold it against the tag body where the ferrite coil sits (usually the side opposite the lock), the tag stops picking up gate signals. The coil loses inductance and the electronics “think” they’re in silence.
Deep dive: Sensormatic SuperTag 3T
One of the most advanced examples is SuperTag 3-Tone Alarming (3T). It’s a version of the legendary SuperTag with “brains” and a battery added.
Sensormatic SuperTag 3THow it protects:
- Pin loop: The pin is part of the electrical circuit. If you bite through the pin or rip it out by force — the circuit opens and the alarm trips. However, if you open the lock with a hook, a mechanism inside presses the contact pad and opens the circuit “legitimately” without triggering.
- Field detection: The AM coil inside the tag listens for 58 kHz. When it hears it — it turns on the siren.
How to work with it (Pro approach):
Use a standard Sensormatic hook. Insert the hook, press the mechanism, pull out the pin. If you only want to remove the tag and leave it in the store — put the pin back in. No sound.
Insert the hook. Firmly cover the tag’s buzzer with your hand (to muffle the sound). Pull out the pin, then remove the hook *without the pin in*. The tag will give a short “BEEP” and disarm. After that it’s just a piece of plastic you can carry out like a normal 1-alarm tag.
As above: a strong magnet held against the ferrite area (the side opposite the hook hole) saturates the core. The tag becomes “deaf” to the gates and won’t trigger when you walk through.
🚫 What not to do
Crude methods like chewing through the housing with pliers are unprofessional. They make noise, leave traces, ruin the item’s appearance, and if you’re caught they count as intentional property damage, which makes the legal fallout worse. That said — we’re not in rainbow-pony land; if there’s no other way and you really need to, study carefully where the actual sensor is inside and act accordingly.
Knowing the technology is your main advantage. 3-Alarm tags are built to scare beginners, but for those who know, they’re just devices with predictable behaviour that can be bypassed if you understand the physics.