All PIEPS avalanche beacons are capable of processing a signal from an older analog beacons that were originally set to transmit on the 457.00kHz frequency. The further away from 457kHz an older beacon gets, the harder it is for any beacon to detect a signal.
The PIEPS Digital Signal Processing (DSP) models are the most advanced beacons on the market for dealing with signals from older analog beacons. DSP Models are capable of picking up a -150Hz to a +100Hz deviation from the 457 kHz frequency. After the release of version 2.8 (Summer of 2005) DSP models were updated to cover the entire -500 Hz to +500Hz from the 457kHz frequency when using the SCAN function.