Review on SURECOM SF401 Plus: Advanced Frequency Counter with CTCCSS/DCS Decoder for Radio Transceiver by Kevin Huot

Sometimes you need to be really close to the device you want to scan. By close I mean almost touch, but if you're just trying to determine what frequency something is tuned to (that doesn't provide information natively and isn't digital) then that usually works pretty well for us. We use it from time to time during some of our tests and it has come in handy a few times since we added it to our collection of tools and gadgets. Of course, this will not give you any results (usable results) if the device you are scanning is digital/encrypted.