Global articles on espionage, spying, bugs, and other interesting topics.

Why Cheap Bug Detectors Do Not Work

On average, we get an enquiry a week asking about RF (bug) detectors available online. There are a plethora of these devices for sale via spy shops, Ebay, Alibaba and a myriad of similar shopping sites. The problem with most of these devices is that they just don’t work! The manufacturers and resellers of these types of products are relying on your paranoia to sell these devices, ultimately resulting in ‘money for jam’ on their end.

“But I bought one and it constantly alerts me to a bug in my room!”, I hear you say.

Well of course it does – otherwise you’d probably complain and ask for a refund. The modern radio spectrum (all the invisible signals floating through the air) is somewhat overcrowded and range from local radio stations, to weather sensors and mobile phones. In fact, there are few electronic devices available today that don’t transmit some form of signal, whether intentionally, or simply via spurious emanation. So, whilst your detector is screaming blue murder, it’s probably picking-up everything but what it is supposed to!

Without going into intricate technical detail, the majority of these RF detectors are simply broadband radio receivers, built using cheap electronic components, with little or no filtering and virtually no ability to finely tune a signal. They therefore pick-up everything (well almost). These detectors will flag signals that are supposed to be there and not necessarily the ones that aren’t.

For example, a cheap FM listening device (electronic bug) bought online for say, $15, will transmit somewhere between the frequencies of 88MHz to 108MHz. They might power out to a few hundred metres if you’re lucky and by tuning using your car stereo or any other commonly available radio receiver, you will probably hear the target environment. Tune being the operative word. Your newly bought detector will technically pick it up, however, it will also pick one of scores of radio stations in the same frequency range, because it is not locked to the specific transmitting frequency of the bug and being a broadband device, it usually can’t be tuned.

But Why?

Radio stations transmit at phenomenal strengths to reach their audience. They have huge transmitters that chew up a stack of juice! So, your small $15 FM bug just can’t compete. Your cheap RF detector generally won’t have the ability to distinguish between the million dollar radio transmitter and your $15 battery operated listening device! The flip side to this of course, is that if you desensitise your receiver (turn down the pick-up ability), then they will most likely  detect nothing – in most cases, their parts are just too cheap and nasty. That’s not to mention the lack of quality antennas on these receivers.

The above said, not all receivers are that bad – just most of them. Have a look at a few of the cheaper detectors listed on the likes of Amazon and read the reviews. They either buzz or alert constantly, or not at all.

If you have a genuine need to detect a domestically available listening device, then approach a professional counter-surveillance product supplier and expect to pay in the thousands of dollars range…

The equipment we use to detect radio transmissions has seen us invest hundreds of thousands over the years and even then, there’s no guarantee (although if our gear can’t detect it, there’d be few others’ who could).

Don’t be sucked-in by the marketing hype. In an ideal environment, out in the back of nowhere, their receivers might have some benefit – but they are no substitute for genuine counter-surveillance receivers.