why 406 beacons are bad

[lordmonar]

Bottom line.....you are way to late to this argument to be bringing up "arbitary" changes as the reason why you don't like it.

Move on.

No, the bottom line is that we have lost a capability that is used to save lives, and it has been removed arbitrarily and unnecessarily, when the new stuff could have easily been ADDED.

But what the heck, I've only been doing SAR and communications since the early 1970s, both in CAP and professionally, so it's not like I actually know anything about it, compared to an expert such as yourself.

So....if you were such an expert....why did they just ignore your wisdom? 
Dude....I can do the Ad Homins too.

Let's agree to disagree okay?

[Buzz]

if/when you do get the call you will not be out looking for some carrier only signal that turns out to be some defective TV tuner or a USB hard drive......because of the digital encoding.  So less false alarms, less wild goose chases for an ELT in a hanger..

how does a TV tuner or a USB hard drive send a radio signal? Just wonderin'

A TV tuner receives the over-the-air frequency, then converts it to an "intermediate frequency" (or sometimes more than one), the same as your satellite TV box.

A computer operates at several different radio frequencies.  A USB drive can act as an antenna for the frequency which it's operating on, and most are pretty much unshielded.

[Buzz]

So....if you were such an expert....why did they just ignore your wisdom? 

They ignored the wisdom of several hundred people wiser than I, who wrote and testified on the subject during the (brief) decision-making period.

Let's agree to disagree okay?

The ONLY place that we disagree is on the FREQUENCY.

Consider 406 to be Beacon Superhighway, the beautiful, smooth new 21-century 8-lane with onramps and offramps for everyone.  Compare this to Route 121.5, ELT Road, the four lanes laid down in the 1940s, with dips and the occasional pothole.  This decision takes most of the traffic from Route 121.5 and puts it onto Beacon Highway, with every other user in the world, simply because it saves a couple of thousand dollars for the Highway Department.

When you had a flat on Route 121.5, the tow truck from the nearest town would come out and find you, often assisted by the local hot rod club.  If you get the same flat on Beacon, the Freeway Authority Recovery System is the only resource.  They promise to give you faster service, but they are the only game in town. 

There is no reason, technologically, to put all traffic onto Beacon.  Anyone who has ever worked with digital communications will tell you that there are several major reasons that a 406 beacon might be operating properly but doing no good.  A burst of static that trashes the first part of a data frame will result in the entire frame being disregarded.  Likewise a collision between multiple frames from different transmitters.

In computer networking, an acknowledgment is sent from the recipient to the sender -- if it isn't received the frame is sent again.  In the 406 system, there is only one-way error checking (a checksum in the data frame).  This is fine, if yours is the only signal being sent, and the weather is good.

Planes don't crash unless the weather is good . . .right? 

By putting the digital on 121.5, the chance of frame collision is miniscule compared to putting it on 406 with the massive number of accidental activations, lost kids, out of gas backcountry Jeepers, hikers, etc.

Of course, we should be involved in some of those searches, but the ideal would be a separate beacon frequency for each person in need, with second best being a frequency for each TYPE of users (aviation, kids, hikers, boaters etc), the same as an idea highway would give each vehicle its own lane (with second best being bus lanes, truck lanes, car lanes, etc).  Instead, we have Radio Rush Hour, with all of the possible nasty scenarios, and the Highway Department wants to make it the ONLY ROAD IN TOWN, reducing Route 121.5 to a bike path.

[Extremepredjudice]

if/when you do get the call you will not be out looking for some carrier only signal that turns out to be some defective TV tuner or a USB hard drive......because of the digital encoding.  So less false alarms, less wild goose chases for an ELT in a hanger..

how does a TV tuner or a USB hard drive send a radio signal? Just wonderin'

A TV tuner receives the over-the-air frequency, then converts it to an "intermediate frequency" (or sometimes more than one), the same as your satellite TV box.

A computer operates at several different radio frequencies.  A USB drive can act as an antenna for the frequency which it's operating on, and most are pretty much unshielded.

What! Stop making stuff up sir!

I'm not an expert on TV tuners, but they transmit it via CABLE.

The USB drive thing is hogwash.

[Buzz]

True, most SAR agencies would be buying 406 equipment anyway, to find EPIRBS, but the vast majority of locator equipment used in SAR for aircraft is bought and paid for by individuals, not by agencies. 

What?  I'd like to see some evidence to back that up.  While I'm sure there are a few personal DF units out there in CAP, I've never seen one in two wings in 15 years.  And if you're not talking about CAP, I'd like to know what group of individuals is doing missing airplane searches with personal DF equipment and that collectively have bought more DF equipment than CAP and a host of state and federal agencies combined.

Reread -- my fault for not making myself more clear -- and you will see that I mean equipment used for SAR INVOLVING aircraft, not equipment IN aircraft used for SAR.

You're thinking Doppler gear.  I'm thinking aircraft radios, HTs, radio scanners, etc., not only those used by CAP but also by other aviators or volunteers.  Now all of those resources are going to be rendered less effective -- most to the point of uselessness.

"For lack of a nail, a shoe was lost . . ."
 

[JetDriver777]

Ok mr know it all
"Buzz". 406 dosent use just one freq .  There
Are now 10+ freqs being used to send the data. Since 406 only can be used for distress data
Communicatiins the likely hood that the data will get to the bird is much greater than also having voice on the same freq like 121.5.

But you already know that!

It amazes me how little cap folks know about the system that they supposedly interface with every day!

[PHall]

Ok mr know it all
"Buzz". 406 dosent use just one freq .  There
Are now 10+ freqs being used to send the data. Since 406 only can be used for distress data
Communicatiins the likely hood that the data will get to the bird is much greater than also having voice on the same freq like 121.5.

But you already know that!

It amazes me how little cap folks know about the system that they supposedly interface with every day!

So sayeth Mr Anonymous. And your bonefides are what?

[JetDriver777]

Well I'm not an old crotchety fart that knows everything there is to know " becouse I've been around since the 70's"

So you are
Stuck in the old days, and for whatever reason don't like the 406 system.  WHO CARES? You don't like the freq so it's bad? BuzzThe new self proclamed master on RF has spoken!  The FCC and FAA are Morons now because they didn't talk to Buzz first!

And we wonder why knowbody takes CAP seriously!

[Buzz]

if/when you do get the call you will not be out looking for some carrier only signal that turns out to be some defective TV tuner or a USB hard drive......because of the digital encoding.  So less false alarms, less wild goose chases for an ELT in a hanger..

how does a TV tuner or a USB hard drive send a radio signal? Just wonderin'

A TV tuner receives the over-the-air frequency, then converts it to an "intermediate frequency" (or sometimes more than one), the same as your satellite TV box.

A computer operates at several different radio frequencies.  A USB drive can act as an antenna for the frequency which it's operating on, and most are pretty much unshielded.

What! Stop making stuff up sir!

I'm not an expert on TV tuners, but they transmit it via CABLE.

The USB drive thing is hogwash.

The only part of what you wrote that is true is that you're not an expert.

I dunno where you live, but I'm sure that if you look around, you'll see a little bitty round thing on someone's house, with "DISH" or "DirecTV" written on it.  This picks up microwave radiation, and downconverts it to a freqency that your TV can use.  If you look a little farther, on a mountaintop or a tall building, you will find a big tall Erector-set kind of stick thingy, probably painted red and white.  There is a highly-technical term used to describe this -- we electronics folks tall this an "antenna tower."  Stay with me now, this gets pretty technical, but things called "over the air television signals" are transmitted from these.

Neither of these is "transmitted via CABLE." 

Did you sleep through the whole "HDTV transition" thing?  This only affects over-the-air broadcasting, NOT TV sets hooked up to cable.

And if you don't know that a computer and USB interface pump out RF interference, you might want to study the issue before you decide that it's "hogwash."  Try this article from Compliance Engineering Magazine, (http://www.ce-mag.com/archive/1999/julyaug/usb.html).  Or you can do what I do, and use a spectrum analyzer to sweep around computers to chart the electromagnetic footprint (required by one of my clients, who is involved in radioastronomy and satellite communications).

[lordmonar]

The USB drive thing is hogwash.

I tracked a carrier only 121.5 signal to a house in Las Angeles...it was comming from a USB MP3 stoage unit plugged into a computer.

Unsheilded cables with a dirty motor or frequency generator can make all sorts of noise. 

[RiverAux]

True, most SAR agencies would be buying 406 equipment anyway, to find EPIRBS, but the vast majority of locator equipment used in SAR for aircraft is bought and paid for by individuals, not by agencies. 

What?  I'd like to see some evidence to back that up.  While I'm sure there are a few personal DF units out there in CAP, I've never seen one in two wings in 15 years.  And if you're not talking about CAP, I'd like to know what group of individuals is doing missing airplane searches with personal DF equipment and that collectively have bought more DF equipment than CAP and a host of state and federal agencies combined.

Reread -- my fault for not making myself more clear -- and you will see that I mean equipment used for SAR INVOLVING aircraft, not equipment IN aircraft used for SAR.

You're thinking Doppler gear.  I'm thinking aircraft radios, HTs, radio scanners, etc., not only those used by CAP but also by other aviators or volunteers.  Now all of those resources are going to be rendered less effective -- most to the point of uselessness.

No, I think I understood and you still don't have a leg to stand on.  Yes, there is some private gear used for searches involving airplanes, but there is no way in heck there is more of that which has been purchased by private individuals than public agencies and CAP.  No one is more involved in missing airplane search than CAP and there certainly aren't many private individuals buying equipment to locate them. 

[Buzz]

Ok mr know it all
"Buzz". 406 dosent use just one freq .  There
Are now 10+ freqs being used to send the data. Since 406 only can be used for distress data
Communicatiins the likely hood that the data will get to the bird is much greater than also having voice on the same freq like 121.5.

But you already know that!

It amazes me how little cap folks know about the system that they supposedly interface with every day!

Go read the latest Channel Assignment Table.  Those "10+ freqs being used" are actually FOUR "being used," and are aging out, the same way our radios have aged out due to NTIA transition schedules.  One is only for firstgen beacons, designed before 2002 and made until the end of 2006.  Two others offered a production window averaging 7 years.  ONLY ONE is available for beacons approved after January of this year (this window has already been open for two years, with tens of thousands of units produced), and will include the aviation ELT replacements.

There are several RESERVED frequencies, but they are not in use and no projected operational date has been released to the beacon manufacturers.  Following current pattern, this production window will be for the next 5 years, and ALL beacons not currently approved will use this ONE frequency.

[Buzz]

No, I think I understood and you still don't have a leg to stand on.  Yes, there is some private gear used for searches involving airplanes, but there is no way in heck there is more of that which has been purchased by private individuals than public agencies and CAP.  No one is more involved in missing airplane search than CAP and there certainly aren't many private individuals buying equipment to locate them.

If YOU have bought any radio equipment for use on 121.5, that is "individually purchased."  Every radio in every non-corporate plane flown by CAP on a search is "individually purchased."  Every radio tuned to 121.5 by someone flying somewhere in their private plane is "individually purchased."  Unless you want to claim that CAP and other official agencies have bought more of these radios than have all of these other users, I'd say that I'm standing pretty solidly.

[RiverAux]

Every radio in every non-corporate plane flown by CAP on a search is "individually purchased." 

Basically, that system hasn't existed for 20 year or more.  In those extremely rare situations where a non-CAP plane is flown by a CAP member on a CAP mission its going to be used for transport and isn't going to be out flying a grid and other their radio ain't going to be used for anything other than comm. 

[Buzz]

Well I'm not an old crotchety fart that knows everything there is to know " becouse I've been around since the 70's"

Neither am I.

I'm a crotchety old fart that knows everything there is to know because I've been DOING these things since the '70s. 

This is why I stay anonymous out here in cyberspace -- I know a lot of people, in a lot of different fields, and don't want someone doing a web search on my name to know that I'm in CAP (or any of the other things I'm involved with) unless I have chosen to tell them.  It's a lot easier for me to get my consulting fees when clients can't just look up my comments to others and extrapolate from them. 

This crotchety old fart recently was asked by a company to reverse engineer a patented device, because they don't want to deal with the one company which currently holds the license for the original.  I succeeded, and will make not only the original contract amount, but got a performance bonus for bringing it in so quickly, and I hold the patent on the new device.  It actually cost them more to have it reverse engineered than to have bought it from their competitor, and the patent holder would have made a fraction of what I got for doing the project.

In effect, I got paid twice for the same work because the people who hired this this crotchety old fart couldn't just go online and see that I'm the same crotchety old fart who holds the patent on the original.

People pay me a lot of money for what I know.  CAP is my way of giving back to the country, but they might not understand.  I'm sorry that I come off as a smartass, but at least I'm a COMPETENT smartass.  After one launch several years back, at the debrief I noted that, of the 100 or so people there, I had offended probably half.  I apologized to the rest for not having had enough time to rub them the wrong way, too.  I get frequent calls from people that I've irritated over the years, so I have to say that I really MUST be good at what I do, or they wouldn't want repeat engagements.

[Buzz]

Every radio in every non-corporate plane flown by CAP on a search is "individually purchased." 

Basically, that system hasn't existed for 20 year or more.

Not quite true.  The capability is still "on the books" even in areas where all SAR is corporate.

In those extremely rare situations where a non-CAP plane is flown by a CAP member on a CAP mission its going to be used for transport and isn't going to be out flying a grid and other their radio ain't going to be used for anything other than comm.

Also not quite true, but an argument for another time.

[SarDragon]

if/when you do get the call you will not be out looking for some carrier only signal that turns out to be some defective TV tuner or a USB hard drive......because of the digital encoding.  So less false alarms, less wild goose chases for an ELT in a hanger..

how does a TV tuner or a USB hard drive send a radio signal? Just wonderin'

Almost all receivers - radio, TV, radar, you name it - have one or more local oscillators, which can, under the right circumstances, radiate a signal. These signals can cause interference on various frequencies. Sometimes the interference shows up as a carrier-only signal on 121.5, and steps on other transmissions.

Computers also have oscillators that can cause similar problems.

[CJB]

if/when you do get the call you will not be out looking for some carrier only signal that turns out to be some defective TV tuner or a USB hard drive......because of the digital encoding.  So less false alarms, less wild goose chases for an ELT in a hanger..

how does a TV tuner or a USB hard drive send a radio signal? Just wonderin'

Almost all receivers - radio, TV, radar, you name it - have one or more local oscillators, which can, under the right circumstances, radiate a signal. These signals can cause interference on various frequencies. Sometimes the interference shows up as a carrier-only signal on 121.5, and steps on other transmissions.

Computers also have oscillators that can cause similar problems.

Seems like the skeptics on here aren't too familiar with intermod distortion.  An offending device doesn't have to operate on 121.5MHz to cause interference on that frequency.

[SarDragon]

Here's another example - I can tune a cheap FM radio to a freq 10.7 MHz away from specific TV channels, and totally screw up the TV audio. RF emissions are strange things to work with.