I know this thread has been around for a while, but since it is stickied it probably deserves a response. Most of the channel 3 frequencies in the chart (FRS, MURS, CB) are from the Channel 3 Project -
https://amrron.com/communications-resources/ch3-project/ which also has a contact method:
Make Contact In 3 – 2 – 1
– 3 (Turn your radio on and set it to Channel 3)
– 2 (Attempt to broadcast for approximately 2 minutes)
– 1 (Attempt again every 1 HOUR, on the hour, to save batteries)
What they have as GMRS17 - 462.6Mhz - is the old GMRS channel 3. Current GRMS 3 is 462.6125 MHz. You might want to be aware of this in case you have a mix of old new radios and are wondering why you're both transmitting on channel 3 and can't hear each other. Amrron uses 462.6125 MHz for GMRS channel 3.
I believe the PMR UHF frequency listed is for European license-free band - essentially their Citizens' Band. I could be wrong on that, but I don't know that would be useful info to have here in the USA.
Many of the frequencies labeled "Prepper" or "Prepper Nets" are AmRRON frequencies, though I don't think those are all accurate anymore, though some are. I think the list may have been made based on the older TAPRN nets, which then got merged into AmRRON.
146.550 MHz was once petitioned to the FCC to be the designated national emergency frequency, but it was denied in 2012. People still push for this occasionally, which (I assume) is why this would be included on the list. Most everyone else defaults to 146.520 MHz, the national calling frequency.
