Police radios can trigger positive breath test, at least with the equipment used in the UK, according to an ex-police officer informant for The Register who revealed that while at training school they were taught never to hit the transmit button on their handset while waiting for the breathalizer analysis to finalize. This leads to inevitable speculation that an officer “might surreptitiously give a
quick burst of transmit on his radio whilst his partner was
administering the breath test to an uncooperative suspect.” Even if the suspect is eventually acquitted, they will have been paid back for their cheekiness with massive inconvenience. The Register article advises those stopped for suspicion of driving under the influence to request that the officers turn their radios off. Let’s forget for a minute the fact that you ought to be caught if you drink and drive. IMHO it would be better for you to just keep an eye on their itchy fingers on their handset triggers and, if they transmit, you might be able to use the facts above to invalidate any positive test findings. (It’s akin to the way in which you can get your radar speeding citation dismissed if you can establish that the officer doesn’t know how long it’s been since the radar gun was last calibrated.)