Here's something I did as a goof when I was a young lad of sixteen, but it may be useful to some of you McDonald's activists...A buddy of mine was into amateur radio, or ham radio if you prefer. He had a technician's level license from the Federal Communications Commision. My part--I drove the car, since I was the only one of my fiends with a car. At noon, we drove to a local Taco Bell outlet and interrupted their lunch business by knocking their wireless drive-thru headsets off the air, and harrassing the customers in the process. When a customer tried to place an order at the speaker, my buddy would press the "XMIT" button on his ham radio transceiver, and goof on them. For example, "Six tacos? No wonder you're so damn fat!!", or, you get the idea. Nobody could place their orders, and my buddy and I got a great laugh out of it. Now, let me explain how it works...
A wireless drive-thru intercom consists of one or more HEADSETS, which are worn by workers, an outdoor SPEAKER, and a CONTROL UNIT transceiver, which acts as a go-between for the other components of the system. A metal detector imbedded in the concrete near the speaker alerts the headset wearers when a vehicle approaches. The speaker is hard-wired into the control unit, which transmits the sound from the speaker at a low frequency to the headsets. The headsets transmit at a higher frequency to the control unit, which repeats that broadcast over the speaker. When a high frequency signal from a headset is detected by the control unit, it stops transmitting sound from the speaker at its assigned low frequency until that high frequency signal stops, which is when the wearer of the headset quits talking.
Here is where knowledge of ham radio comes in. The headsets transmit their signals at an assigned frequency somewhere between 50 and 60 MHz. For the sake of our discussion, let's assume your local McDonald's uses 54.1 MHz FM. A ham radio transmitter, when new, will tune in that frequency, but must be modified before they can transmit at that frequency. Fortunately, this is a simple process of opening the transmitter and cutting one wire. Now, the headsets have two buttons, "A" and "B". When the operator presses "A", he can talk to the customer at the outdoor speaker, and this will also be heard by other workers wearing other headsets. Pressing "B" allows the wearer to talk to his cohorts wearing other headsets, but the outdoor speaker will not repeat. Since the headset only transmits at 54.1, how does the speaker know whether or not to repeat this signal? The answer lies in the control unit. Pressing "A" makes the headset transmit a tone as well as the operator's voice, while "B" does not. The control unit removes the tone, when present, and repeats the sound of the operator's voice over the speaker. No tone, no speaker. You must find the frequency of this tone to activate the speaker. Most ham radios have tone generators.
Bring your ham radio transmitter to McDonald's, and sit in your parked car near the drive-thru. Tune in low band FM frequencies until you hear the sound of the headset wearers on your transceiver, but don't transmit anything yourself yet. You must find the right tone frequency next. The control unit is rarely turned off at night, so come back after closing and experiment. Change the tone frequency until you hear your own transmissions on the speaker. Now, it's time to GOOF!
Come back during heavy business times for McD, and just use your imagination. Your transceiver probably brodcasts at about five watts, which is more than enough to knock those 1 watt headsets off the air. Goof on customers, spread propaganda, curse at them, it's all up to you. Be careful; G-men can track down the source of your offending transmissions, but I get the impression that McD activists don't mind the prospect of getting caught.
I have no other imformation on ham radio; you should seek the advice of somesone who knows more about it. If your McDonald's uses a hard-wired drive-thru intercom system, forget it.
Do you Britons, Aussies, Canadians, etc., even have amateur radio?
Stay tuned,
Hugh Morris
