For those not too familiar with the Dutch pirates, their names, their frequencies, there could have been some confusion on 183 metres this evening.
On 1617 kHz you could hear Radio Turftrekker (Turf tractor), while up the band on 1656 kHz was Radio Turfsteker (Turf cutter). Similar names and easy to confuse. But a handy pointer is that Turfsteker can nearly always be heard around 1655, while Turftrekker is at home around 1615-1630.
Many of the Dutch MW pirates use coil antennas which have a very narrow bandwidth. This means moving up or down the band by only a few kilohertz can affect the efficiency of the antenna, which is why most stations stick to a similar frequency each time they broadcast. Think of Matrix, for example, and he is usually around 1670; Casablanca 1647; Utopia 1620; Keizer en Keizerin 1636; Witte Tornado 1647; Pandora 1636; Veronica 1640; Zonnester 1620; Moby Dick 1648. The list goes on and on . . .
While stations like to have their regular channel so listeners know where to find them, it's also as much to do with the antenna. So, next time if you're not 100 per cent sure who you're listening to, the frequency might just give the game away.