Emergency Beacon Configuration

Sam, Pete, Allen and all the other APRS experts, I am configuring my MT-8000FA and in doing the research for setting up a secondary configuration, I can't seem to find much information on setting up for a 'secondary', be it an emergency beacon or perhaps a configuration for an alternate vehicle. I think, Sam, you made a reference to an upcoming secondary configuration setup as an emergency beacon, and your unworthy geek groupies are anxiously awaiting your input.

Anyway, absent your input, here's what I came up with (as Pete would say, WARNING GEEK ALERT):

1. On the 'secondary' setup page, change the icon from an ' to a ! and the alternate table symbol, \, thus rendering an "emergency" icon. Alternatively, you could use the 'Crash site' symbol?

2. Use the same frequency, 144.390 MHz, but what is 144.340 MHz for, and why is it the default on the secondary page?

3. On the 'Status' block, insert after your call sign, 'DECLARING INFLIGHT EMERGENCY - Please notify emergency responders!' as someone else has suggested. Check the 'Send every' block for a "1" to make sure the message gets sent out in every packet.

4. On the MIC-E settings block, change the 'Message' from 'Enroute' to some other choice?

I can hear Allen thinking, you better be VERY careful to make sure you don't inadvertently move this switch because you'll have the whole ham world out looking for you! This is a good thing, but I do have a locking toggle for this purpose, see pix below.

All right guys, where have I gone wrong here and please add any other suggestions.

Here is my rig setup. Right now "I'm all dressed up with nowhere to go"...waiting for my license to get posted, everything else is ready to go.



And all closed up:



The enclosure, the fuse holder, and the SMA to BNC adapter, were obtained from Mouser Electronics. The enclosure is a PacTec model HP.

Thanks to all the guys on this forum for getting me started in APRS!

Very Nice, Pat! That is the most attractive tracker packaging I've seen.

Your secondary config looks good. I think 144.340 is the European freg, but yes, reset to 144.390.

You might consider setting packet interval for a manual setting of ten seconds or so instead of the customary 60 seconds.

Including a phone number in the text box might be good, maybe a personal contact who would know how to get the SAR chain started.

Your license should be posted within a few days of your exam. If not, it might not hurt to check with the guys who administered the exam in case something feel through the cracks.

144.340 is a frequency used in a number of US locations for low power operation. Seattle is one that comes to mind. The European APRS frequency is 144.800.

Allen
VHS

Thanks, Sam. Good suggestions. Hope you'll critique the first flight when it happens...I'll let you know. I took the test last Wednesday so it'll probably be another day or so.

Pat,

Really nice looking package...nice work! Where'd ya get the locking mini-toggle...is that from Mouser too?

I played with setting up the secondary profile as an emergency beacon, and did the following (just some thoughts and a problem I saw when setting the configuration):

I left the icon as an airplane so anyone that sees it would know to look for an airplane (and an emergency icon sounds like a good idea too...either could work well).

In MIC-E, if you scroll down in the drop down menu, there is one item that says "Emergency!"...thats the one I selected, and when I hit the CONFIGURE button, it pops up a warning that says "You are about to configure your tracker with the abilty to send an emergency beacon. Are you sure you want to do that?" (So that MIC-E setting will work.)

In the status window (and this is where I had a problem), in the primary profile I said "KF7GWS RV-6 Airborne", and in the secondary profile I said "KF7GWS RV-6 emergency, (775) 544-3511 to verify"...kinda like Sam suggested. When I tried to hit CONFIGURE, it popped up a warning that said:

"The Primary or Secondary Status Beacon is too long and has been truncated. To have a longer status beacon text, use fewer digipeaters, and make the primary and secondary callsigns, digipeaters, or status texts identical."

It basically chopped almost all of the status block, including the phone number. I couldn't figure how to make the digipeaters identical, so the only way I got it to take the config was to make the call sign blocks identical (they already were) and then make the status blocks the same (which takes away the ability to put in a different message for an emergency).

Maybe Pete, Sam or Allen could detail how to make the digipeaters the same so a different status message can be used (if that is possible)...but thought I'd pass it along to prevent the frustration I was running into. I currently don't have the secondary profile set as an emer-beacon, but rather as a race beacon...but would like to be able to set the emergency beacon with a special message. If you have success with it, please post how you did it...and thanks!

Cheers,
Bob

Locking Toggle

Thanks, Bob. The locking toggle is Digi-Key p/n 360-1786-ND, they're nice, I've used them before, about $7.

Good suggestions. The only way I know to shorten the digi path is to just use the high-level digis and one hop (WIDE2-1), which is probably all you're going to need for the emergency beacon. I think I remember reading that there are a maximum number of characters allowed in the packet, so I'm assuming everything else has priority and the status message gets whatever is left over, and thus gets truncated as necessary. Unfortunately, there's no good way to test an emergency beacon that I know of. Hopefully Allen will chime in here!

And it may be a while before I get to test my rig. I think I am in for some extended delays with my license being posted--D.C. area expecting another 20" and the government is shut down now!

P.S. I take it all back! License is posted: KJ4RZN !!! Let's go trackin...probably be Thursday, have a flight up to DeLand. But I might go once around the pattern tomorrow to see if it's working!

Thanks for the part number Pat...I've looked locally and couldn't find one...that helps mucho!

What call sign will you be using...HAM call or N#? Will look for you!

Cheers,
Bob

Testing the Emergency Beacon

I have never sent an emergency beacon out into the atmosphere. If I felt compelled to try a brief online test, I would add a comment stating "TEST ONLY!" to the transmission. Otherwise, if you just have to know if its really working, you could set up a local receiver. AGWPE, WinAPRS, and run your transmitter into a dummy load, or find someone with a Kenwood Radio and do it on a non-APRS frequency. Knowing hams, its likely to cause excitement, but I don't think it will cause anyone to vapor lock. Personally, I would test with another MIC-E message, and assume that switching it to the emergency beacon would not cause any changes. ( well, I might use someone else's call sign who foolishly sent their Micro-Trak in for repair, but I am evil that way...)

Allen
VHS

Bob, Allen, Sam:

Allen, sounds like a project for Byonics! Seriously, how about a dummy load/receiver that would decode a packet and readout into a PC. Doable? I'm sure the aviation community would love an item like that. We got to know if it works! Keep in mind that we test our ELTs regularly.

Bob & Sam, I'm planning a test flight tomorrow morning at 10 a.m. eastern (15z). Hope that's not too early for you Bob. By the way, Reno is my birthplace and I have a sis who lives there! I'll be using the tail number (N44PH) for the call sign. Hope to catch you guys tomorrow!

Just depends on whether I make my commute flight home tonight

Ah, the glam life of the airlines!

Will be watching!!

Cheers,
Bob

Oh, and let me know when you come out to visit your sis!!

Lookin' Good!

Pat,

Track looked great to me. Looked like a fun flight! Looked like it tracked you well from taxi out to taxi in. On the ground, you were hitting a repeater in South Vero, and airborne you were hitting stations in Palm Bay...even hit one over in Winterhaven! And those aileron rolls east of Blue Cypress Lake looked very nice!



Here's what it looked like close in to the airport...even showed the turn in the runup area! Nice!



Oh, and next time try using the taxiways!



Lookin' Good!

Cheers,
Bob

Success!

Hey Bob,

What a blast!

Thanks for posting my track! This is by far the coolest thing I've done with my airplane! Well, maybe in the last year. Looks like the WIDE2-1 digi path will be fine for the local area. Probably the whole state actually. Sam's experience and guidance sure saved a lot of aggravation!

One observation for you: I am getting the same packet-burst noise on my COM1 antenna as you--but only on the ground. Go figure. Actually, it was kind of comforting to hear because I knew it was working while I was taxiing out. I think I might have heard it once, maybe twice airborne too. My theory is that on the ground the RF is radiating off the taxiway. When I get my antenna, I'm planning to locate it as far back on the belly as I can get it, probably just aft of the baggage compartment. My COMs are forward of the wing spar, so I hope this is far enough back to eliminate the RF noise. We'll see and report back.

Thanks for all your input and thanks to Sam and Allen as well! Flying up to DeLand, FL tomorrow to have lunch and back in the PM. Should be fun!

Good stuff Pat!

Interesting note on the bleed-over. How far apart are those antennae?

I hear it airborne, but it is a little less noise there. Thought it just might be the "RV roar" drowning it out, but perhaps there is some "ground effect" involved. Will be transmitting with the SAR radio through that antenna Saturday, so it'll be a good test.

In the meantime, I'm looking into a notch filter to shield my SL-40 from 144.39 and 150.25 (and a few other freqs); or a band-pass filter to shield the SL-40 from 144.39 and up. The gent at High Sierra Electronics that I talked to today said the band pass might be better, as a notch for that wide a frequency range would be expensive to do well, and might block RF down into the normal comm range (below 135.95). He's cypherin' on it and we'll see what he comes up with for ideas.

If you, Allen, Sam, Pete or anyone have any other thoughts on this, I'm sure open to ideas (I do know moving the antennae might do it, but am trying not to cut more holes! )

Glad you're APRS'n away!!

Cheers,
Bob

rvmills said:

Interesting note on the bleed-over. How far apart are those antennae?

Bob

Click to expand...

They are mounted as far apart as I could get them in an RV-6, probably about 28-30". I'll measure tomorrow. Meant to do it today.

My thought would be to let the antenna experimenting run its course before messing with filters. For me, a filter would be a last resort. Hopefully you'll find the perfect antenna and placement!

Here's my current working theory: the antenna propagation pattern for the COM antennae might be a figure "8" extending along the lateral axis. If this is correct, moving the APRS antenna aft might get it out of the figure 8 lobes of the COM antennae. That's my operating theory and I'm hardly ever right, but I am forever optimistic. I'll let you know how the LORAN antenna aft works out in about a week.

Good luck and let us know what you find out.