"I'm not abdicating trying to transmit on 243.0, just saying that while the military radio monitored guard freq automatically,"
I expect that military aviation radios do that for the same reason that military vehilces have 12V electrical
systems. Someone decided a long time ago (in the 1940's) that this would be a good idea and wrote a procurement regulation saying "We're not gonna buy it unless it has a 12v electrical
system" and in the same way, someone decided a common guard channel would be a good idea--and then simply wrote a procurement spec that said "We're not gonna buy it unless..."
That's all it takes. Clever, really.
" I know of no such civilian radio that does."
Well of course not. Civilians are a herd of cats, there's no one to write procurement regs for them. However, many marine
VHFs have the capability to automatically dual- or tri-monitor multiple channels at the same time, and 16 is usually a one-touch setup for those. Not 121.5, because that's still an aviation channel.
"I don't know of anyone that leaves a radio set to 121.5, that means you have one less radio to use."
You are kidding me, right? What, you retired when crystal-bound radios were still the standard? These days, radios are digital and monitoring two or ten or scanning a hundred channels pretty much in a second or two, is normal. Ham radio, marine
VHF, ICOMs and other that do air bands...my ham h/t will scan all the tower and ground frequencies for an airport
, and 121.5, and run through them all in a second or two.
No one dedicates a whole radio to one frequency, unless it is a rich or obsolete military installation
. Yeah, I know, B52s and missile silos are still using 1960's technology...that's not the real world.
"Most Airliners crossing oceans will leave a radio set to 123.45 " Rich owners with obsolete equipment
"If your trying to get an Airliner on a remote
chance you have an aircraft handheld VHF, you'll have far more luck with 123.45 than 121.50" And the wonderful thing is, I don't have to dedicate a radio to it, or buy crystals for it. Just change the channel.
"But would the Coast Guard responding to an EPIRB
, be monitoring 121.5, and Aviation only emergency
freq?" Apparently, from published reports, all SAR air responders do. The reason that EPIRBs are mandated to broadcast a 121.5 signal, is so that approaching aircraft can d/f on the 121.5 signal. RDF is still a more certain way to find something, than "well we got these numbers from some guys who got these numbers from some guy who..." and with fond memories of LORAN
C and timing skip, numbers can be worthless compared to a needle[sic] that says "THAT WAY".