> > Many Burger Kings have a full-duplex cross band radio/repeater > > system in the drive through operation. No voters but there is > > an included sensor input to detect cars at the order take window. > And don't try to tell me that you haven't, at the very least, > _thought_ about messing with the order-takers...
What can I say.... it's interesting to see how they deploy the various systems. Some are half duplex, some are full duplex, some are carrier squelch inserting ctcss when the system becomes active and even a more wild ctcss drop to carrier squelch when the system is active. Cross band and same band operation... > If memory serves, 154.570 (a MURS channel) was the freq used > from the customer to the window. Depends on who made the box... I find the newer systems using UHF for one half of the conversation and sometimes duplex with both. In many cases no duplexer... split antennas or much larger tx/rx frequency spacings on the order of 10 and 20 MHz. At least one local Taco Bell uses a cross band system with low-band. I also found one system using a carrier current (about 1730 KHz) FM system... you could talk to it using a Radio Shack Intercom and I saw "extra stations" in the back areas using said... The Opto Electronics Explorer unit is a wonderful thang' I found a local Starbucks (evil empire) on a UHF 452/457.xxxx MHz pair while driving by on the main road out front. Most of the "fun" is found by simply turning your local monitor (scanner or radio) receiver volume up for the reverb, echo or edge of feedback effect. Or.. have a 2 watt license on one of the common order box splinter UHF pairs so I'm legal to maybe try and and place my order early. > Here's something for you Skipp, down the road from you a bit. > I got a chuckle out of it - 121 kilometers of service area for > Jack in the Box and Taco Bell drive-throughs? Frequency > coordination at its finest. > http://fjallfoss.fcc.gov/edocs_public/attachmatch/DA-07-3072A1.pdf > > --- Jeff Classic joy...
