Just to clarify my previous post. If you're lucky enough to be in a 'first world country' when the SHTF, it will more than likely have a EBS/EAS so all you'll need is a battery powered TV or radio and the EAS should give those frequencies out at that time. [barring an incompetant govt employee or total loss of infrastructure] So the channels to use will be given out via EAS/EBS on TV or AM/FM Radio.
And remember, the governments will want to give this information out over frequencies that are easily accessable to their average citizens. That's why I mentioned programming a scanner group with CB/FR/GRMS frequecies, because they are the ones that the average citizen can afford the hardware to utilize. And they're analog, so that's a cheap scanner. The scanner has those frequencies already programmed but they will be separated by a few hundred other frequecies that may take more than a minute or two to scan. If you program these as a scan group it only takes a second or so to scan them all and so you really can't miss a transmission on that group.
Also the average citizens' hardware doesn't scramble or is not encrypted so you can monitor most of the traffic in your AO, be it for good or bad. If there are people operating with digital equipment or with any equipment that can scramble a signal, and they do scramble their transmissions, you won't be able to listen to them no matter what your hardware investment. [maybe just the burst that lets you know someone may be in your AO with that type of equipment.] But for you and your 'clan' you should probably invest in the more sofisticated hardware that allows you to scramble your signal, so you can operate without being monitored. [by most]