http://www.cnn.com/2004/SHOWBIZ/TV/1...eut/index.html

73,
Chip N1IR

"Fractenna"
http://www.cnn.com/2004/SHOWBIZ/TV/1...eut/index.html

One thing doesn't make sense.

If it was emitting on 121.5 MHz, then why was it first picked-up by a
satellite, as opposed to the dozens of aircraft that would have been passing
overhead in the time before the satellite passed over ?

The Truth !! - as filtered through journalism students sigh.

Makes perfect sense. The US and Russia have Sarsat/Cospas satellites
that monitor international distress frequencies (121.5, 234.0, 406
MHz) and alert regional search centers. This system can detect and
report much faster than random aircraft monitoring enroute. See
http://www.faa.gov/ATpubs/AIM/Chap6/aim0602.html.

73 de Benton, W4PE

On Mon, 18 Oct 2004 21:06:29 -0300, "Bob McBeth"
wrote:

"Fractenna"
http://www.cnn.com/2004/SHOWBIZ/TV/1...eut/index.html

One thing doesn't make sense.

If it was emitting on 121.5 MHz, then why was it first picked-up by a
satellite, as opposed to the dozens of aircraft that would have been passing
overhead in the time before the satellite passed over ?

The Truth !! - as filtered through journalism students sigh.

If it was emitting on 121.5 MHz, then why was it first
picked-up by a satellite, as opposed to the dozens of
aircraft that would have been passing overhead in the
time before the satellite passed over ? The Truth !! -
as filtered through journalism students sigh.

"Benton"
Makes perfect sense. The US and Russia have
Sarsat/Cospas satellites that monitor international
distress frequencies (121.5, 234.0, 406 MHz) and
alert regional search centers. This system can detect
and report much faster than random aircraft monitoring
enroute. See
www.faa.gov/ATpubs/AIM/Chap6/aim0602.html.

The malfunctioning TV was reportedly 'transmitting' on 121.5 MHz. Detecting
121.5 MHz by satellite is done from Low Earth Orbit (LEO) and depends upon
waiting for a satellite pass (typically several hours - not
instantaneously). I would have thought that there was more air traffic
(airplanes) over Oregon than that - most places have lots of airplanes
passing overhead nearly constantly.

Perhaps it was his exact location and blockage by mountains. Maybe the
timing was coincidental. OK then...

Benton wrote:
Makes perfect sense. The US and Russia have Sarsat/Cospas satellites
that monitor international distress frequencies (121.5, 234.0, 406
MHz) and alert regional search centers. This system can detect and
report much faster than random aircraft monitoring enroute. See
http://www.faa.gov/ATpubs/AIM/Chap6/aim0602.html.

73 de Benton, W4PE

On Mon, 18 Oct 2004 21:06:29 -0300, "Bob McBeth"
wrote:


"Fractenna"
http://www.cnn.com/2004/SHOWBIZ/TV/1...eut/index.html

One thing doesn't make sense.

If it was emitting on 121.5 MHz, then why was it first picked-up by a
satellite, as opposed to the dozens of aircraft that would have been passing
overhead in the time before the satellite passed over ?

The Truth !! - as filtered through journalism students sigh.




Actually the Russian COSPAS satellites have long since gone out of
operation and Russia has no plans to launch any future birds in this series.
The reported incident concerning the plasma TV transmitting a signal on
121.5 is one of the reasons that this frequency is being discontinued as
a primary frequency. Current regulations dictate the use of emergency
transmitters on a general frequency of 406 mhz. There are more than one
channel in use due to the large and growing number of ELT/EPIRB/PDR
units out there. For ground search the 406 units include a 121.5 low
power transmitter.
A properly registered and equipped 406 radio can reduce the search area
from a 20 mile radius to less than 5 miles. GPS augmentation can lead to
a radius of 15 meters or less.
I can't tell you how many false ELT tracks I have worked on as a Ground
Team Leader for the Civil Air Patrol but I did work on an actual track
as Incident Commander that resulted in the location of a double fatal
air crash. Aircraft and satellites reported the elt signal and my ground
team, guided in by aircraft, walked right up to the crash. In fact the
df operator tripped over the engine.
As to why the satellite picked up the elt and not an aircraft. The
satellite is designed to pickup the elt and all the aircraft is doing is
listening to 121.5. The commercial pilots have and do pick up a lot of
elt signals. Usually the satellite has also picked up the same elt
sometimes not.
Radio signals are funny things Sometimes you can walk right up to the
transmitter, sometimes you have to work for it.

I encourage you to look into the Civil Air Patrol. We are the official
USAF Aux. A full member in Homeland Security since before Homeland
Security was popular.
Look up web page: www.cap.gov for information about CAP.

Dave Nagel, CPT CAP