Older Beacons must be Replaced

Starting on Feb. 1, 2009, NOAA satellites will only receive signals from the new 406 MHz frequency beacons. The older emergency beacons, operating on the 121.5 and 243 MHz frequencies, will no longer be detected by SARSAT. Signals from the 406 MHz beacons can be detected instantly, are more accurate, and offer global coverage. NOAA has provided advance notice of the switch since 2000.

“It’s vital that anyone with the old 121.5 MHz beacon make the switch to 406 MHz beacons immediately so their distress signals can be heard,” said Chris O’Connors, program manager for NOAA SARSAT. “Plans for this changeover started in 2000 and we want everyone that relies on these devices to have the proper equipment.”
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I may be wrong, but I think those freq.'s may have been the CONUS dust-off freq.'s on some of the army bases I visited also. Wonder why they sound so familiar?

Around the US I know there are a bunch of tower/approach freq's and MOA freq's around 121mhz. Most have matching UHF freq's also. I wouldn't think the 121.5 would be used on VHF AM, but, a similar one, maybe 121.650 would have jogged your memory. I think that happens to be a Midway (IL) Airport freq.
(Not to be confused with Midway, a bad memory for the imperial navy)

Nah, I think I may be remembering the old AN-PRC 90 radio I had.

121.5 and 243.0 are the aviation VHF and UHF "Guard" freqs. used for communicating emergencies. That's part of the reason they were used for SAR - aircraft flying overhead could hear the beacon.

The PRC-90 was the military survival radio which has 243.0 for the initial contact/beacon and then you'd go to 282.2 for regular communications and free up Guard.

Doesn't matter. The one time I really needed it, it didn't work.

Up until that time, It always gave me a warm fuzzy having it though.

As far as I have heard they are not requiring the beacons in private aircraft to be changed yet. Many towers and most of the VOR’s still have 121.5 receivers in them. Of course event the 406 beacons transmit on 121.5 so rescue teams can home in on them. With ELT’s it’s the last 100 yards that is the hardest. A lot of automatic reporting systems are on 121.6 we use to use 121.6 for training but had to move to 121.775 for that. Both the 121.5 and the 243 are AM signals. Just like most high tech equipment, the more you need it the better chance it will not work.

243.0 is also the first harmonic of 121.5. ( 121.5 * 2 = 243.0 ).