Bonnie, While your question has been answered quite well by several of us, the main thing to keep in mind is that if you are going to use amateur radio communications, both stations must be operational and within range.
These kind of communication must be done with tactical phone for immediacy and confirmation. If you are mobile and use VHF FM, you will have more modest range than VHF SSB, but should be able to contact your EOC or whoever is dispatching you for local support (such as shelters). Even in our difficult terrain, in the Driftless Region of Wisconsin, we can (mostly) work within the county. Some low areas can not even reach the repeater but may get through (weakly) on SSB based on our test results. If you are portable, you can quickly erect a small VHF gain antenna to increase communication distance. Note the article in the December 2008 issue of QST. We have had to do this even with repeater use for public service support of Adventure Racing. We need to keep in mind that HF use is never a practical option for 24/7 operation. And almost no hams have mobile HF (OK, my wife does if she puts on the Texas Bugcatcher, but she is a rare exception). HF SSB phone can not work consistently once you are out of ground wave coverage which can be only a few miles (5 to 15). VHF works consistently better than HF, for shorter distances and can even work well for longer distances too depending upon power levels and antenna gain and height of stations. When NVIS operation requires a lower frequency than you can operate, (160 meters for example), HF totally fails for short and medium range (typically from more than 10 to even over 200 miles), so it really is not a 24/7 option like VHF. This is especially true at night when the FoF2 can easily drop to only 1 Mhz. Even CW can be of limited use. And remember that during high QRN, which can be common during emergency weather situations, HF phone can be of limited value even if NVIS operation is possible between two points. 73, Rick, KV9U expeditionradio wrote: > The core question still remains: > How can we initiate (push) a message to the > mobile or portable operator in the field, when > the field operator has no expectation that a > message will be sent? > > Or, even more simply, how can we timely notify > the field operator "You Have Mail" via HF? > > During the Katrina disaster the traditional > HF voice nets failed to adequately provide > this type of notification service. > > It's been 3 years since Katrina. > What has we done to improve our ability > to notify field ops via HF? > > How can we work together to forge unified or > standard methods to make this happen... in a > way that will function across the various > ham Emcomm platforms and nets? > > Bonnie VR2/KQ6XA > >
