Here are some options for Lost Model Alarms and on-board Battery Monitors

[cobalt]

Don't even ask how I came to compile this list. :)

The first three seem the best to me (more functions, lighter weight, flexibility for varying voltages, etc.)

Anyone have any recommendations from experience?

hth,
Jason

BC6 Flight Monitor
http://www.yntdesign.com/
Click Prod. >> Elec. >> BC6

Schulze Blinki's
http://www.rc-direct.com/schulze_monitors.htm

BatMon (DIY, schema, firmware, manual, parts list, etc.)
http://www.digitalproductsco.com/batmon/

GEM 2000
http://www.electrotekrc.com/home.htm

DigiAlarm
http://www.californiasailplanes.com/Lost%20model%20alarm.html

Custom Electronics -- Lost Model Alarm
http://www.customelectronics.co.uk/lma.htm
Extraordinary loud version -- lol!

VoltWatch (Monitor only)
http://www.hobbico.com/accys/hcap0330.html

Air Alert Flight Pack Monitor
http://www.hobbico.com/accys/hcap0335.html

Downed Model Locator II (DIY, schema & RadShack parts list)
http://www.ncws.com/rcrock/locator2.htm

Scale-Lites II GEM 2000 (Monitor only)
http://www.electrotekrc.com/scaleII.htm

C-Tronics Flight Alarm
http://www.c-tronicsinc.com/Products.htm

Slope Shepherd (DIY, schema & parts list)
http://www.ncws.com/rcrock/shepherd.htm[/url]

Ni-Cad Sensor (DIY, schema & parts list)
http://www.uoguelph.ca/~antoon/gadgets/ncs.htm

## EDIT: Added MARS Beeper & Club C2VM Sailplane Locator

MARS Beeper
http://zagi.com/html/mars.shtml

Club C2VM Sailplane Locator
http://www.geocities.com/andre25ca/anglais/electronics.html

[jlk]

I have the Hobbico AirAlerts in all my slope planes and they work fine are plenty small and light enough and for $14 a piece a good deal. Some of the rest seem more sophisticated, I mostly fly EPP on the slope, maybe you would want something fancier for a nice glass ship.

Jordan

[aeajr]

This is an amazing resource list. Thanks!

[fdisk]

After some recent personal expierence with loosing planes and using LMA's, I'm on the hunt for the perfect setup.

I put an LMA on a plane after loosing one in a semi-confined area. I lost plane number two in a thermal too far away to hear a locator. Plane number three got a berg receiver because I thought interfearance may have helped keep me from getting out of the thremal when the plane got too far. The berg filters out signals so well that my LMA didn't beep when turning off the TX! Luckily I bought the Hobbico Air Alert which has a timer that will beep if you don't move the stick it is connected to for 1 minute.

I'd like to do even better if possible on my next purchase. I'm looking for an LMA that has the following features:

Timer feature like the Hobbico.

Remote trigger to make it beep NOW!

On board battery to run the LMA, but still have a voltage watch for the rx connection. If the plane battery gets low, beep BUT also if the battery ejects or the LMA disconnects -- BEEP!

Those three features take care of any problem I can think of that can be helped by LMA. I just haven't found one that does it all.

[Hippo]

Originally posted by fdisk
I'm looking for an LMA that has the following features:

Timer feature like the Hobbico.

Remote trigger to make it beep NOW!

On board battery to run the LMA, but still have a voltage watch for the rx connection. If the plane battery gets low, beep BUT also if the battery ejects or the LMA disconnects -- BEEP!

FDisk,

Another one flew away on you? I'm really sorry to hear it. But your ideas sound good. I work pretty closely with the folks who designed that LMA I sent you. (The one you never got to try... :( ) So, I'll get in touch with them and see if they can't do a little software revision.

I don't know if you'll find one with it's own battery. The designers of these things are usually picturing separate receiver packs. But I'll push for the feature.

Thanks for the update.

[fdisk]

I have only lost two and the last one was a couple months ago. I have just been waiting to post this until I had looked around on my own first to see if I could find what I want.

I have also started getting braver again with the new setup but still cautious about going beyond my limits so that also focused my attention on finding the perfect one. Specifically, I had one instance of a rough landing (in plain sight) dislodging the battery which renders my current LMA dead. The "Extraordinarily loud" LMA from above has a battery and can be remotely activated, but I don't think it can tell you low or lost battery or beeps on timer.

Update: I emailed Custom Electronics to see if their LMA has the extra features and just didn't list them.

[erashby]

I assume that since these LMA work off of the Rx that it is at 6v even when using a 10 cell pack, right.

[fdisk]

As long as you have a 10 cell supporting BEC. I have blown up an LMA making the assumption that my BEC would give me a low enough voltage. It didn't.

[fdisk]

Custom Electronics responded. They don't have a timer feature and this is what he said about being able the other feature:

"The version with a separate battery is simply louder. The electronic switch that sets the alarm off requires power (tiny amount) from the rx battery. Sorry the rx battery is not monitored."

So I'm still looking for the perfect LMA.

[DeaninMilwaukee]

"I have the Hobbico AirAlerts in all my slope planes and they work fine are plenty small and light enough and for $14 a piece a good deal."

Question: I've got a couple of these same units, but I thought they had to be plugged into the throttle channel. What do you do on a slope plane?

My reason for asking is I'd really rather have it on another channel as I tend to leave my throttle on one setting for more than one minute and then the stupid thing starts beeping. :(

Can I plug it into a different channel like maybe aileron?


Dean in Milwaukee

[fdisk]

I have my camera trigger plugged inline with my hobbico air alert on channel 6 because I have a berg5 which does 1,2,3,4 and 6. I believe it is the flap dial but I have that mixed on the TX side with channel 5 which is a switch so that it is more camera friendly. Works fine. If I hear the beeping I know it has been too long since the last picture :-)

[aeajr]

Originally posted by DeaninMilwaukee
"I have the Hobbico AirAlerts in all my slope planes and they work fine are plenty small and light enough and for $14 a piece a good deal."

Question: I've got a couple of these same units, but I thought they had to be plugged into the throttle channel. What do you do on a slope plane?

My reason for asking is I'd really rather have it on another channel as I tend to leave my throttle on one setting for more than one minute and then the stupid thing starts beeping. :(

Can I plug it into a different channel like maybe aileron?


Dean in Milwaukee

I have the same unit in my Spirit glider. Wants to be on channel 3 on my Hitec system and looks for an ESC on the other side. If you plug through it on another channel, the servo is disabled.

I spoke to Hobbico support yesterday. This unit is NOT RECOMMENDED FOR GLIDERS. It assumes an electric airplane though this is not stated anywhere.

They said if I put a Y cable on an active channel, like the rudder, it should work find since the rudder is actively used on most gliders.

I will move this to my electric plane and get something different for the glider. There are other locators that are more friendly to gliders. I will get one of them and they are similarly priced in the $16-$25 range

[DeaninMilwaukee]

Next time I pull my plane apart I will give the the y-cable a try.

Thanks!
Dean in Milwaukee

[aeajr]

I put the Y cable in today. Connected the locator to the elevator channel. Works fine. Still, a Y cable adds $6-8 to the price of the locator and is just one more thing hanging around inside the plane.

I think this is OK for an electric, but I would not recommend it for a pure glider or a fuel plane.

Also, it is not all that loud. My next one will be a different model from another source.

[erashby]

Originally posted by aeajr
I put the Y cable in today. Connected the locator to the elevator channel. Works fine. Still, a Y cable adds $6-8 to the price of the locator and is just one more thing hanging around inside the plane.

I think this is OK for an electric, but I would not recommend it for a pure glider or a fuel plane.

Also, it is not all that loud. My next one will be a different model from another source.

Which model do you have?

[aeajr]

I have the Hobbico Air Alert, about $16. I think it is an OK choice for electric planes. Not as good for fuel or sailplanes.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXSZ87&P=7

Look further up the thread for my comments.

I recommend all planes should have some kind of device like this if there is ANY chance it could go down in woods, tall grass or somewhere where the plane might be hard to spot; say, on someone's roof. You might not see it, but if you have a plane locator, you might be able to hear it.

Of course there are much more expensive options, like a walston, but the plane unit for a walston is is over $100 and it is useless unless you have the $400-800 location finder. These are good investments for clubs, especially glider clubs.

[gregw]

Windrider has the DigiAlarm for $17 shipped.

Go to http://www.windrider.com.hk/products/product.cfm?id=3 and the DigiAlarm is listed as "I am here 2 in 1 finder"

I had previously bought one from Canterbury Sail Planes in New Zealand for around $25 (including shipping to Hong Kong) before I found that Windrider also had it available.

One thing I like about the DigiAlarm is that it weighs only 6 grams and is pretty loud.. :D

Also, you don't need a Y cable as it already has a built in connector for your servo..

[crvogt]

Recently one of my planes went down in a Bramble patch near the local glider field, finally found it after a couple of searches. Took about two hours of hard searching pushing throught the thickets and overgrowth. Decided I needed a Lost plane finder quickly. I ordered 2 GWS "be-found-beeper" from Areo-micro for $14.95. I only was looking for a Locator, but much to my suprise it also beeps when the battery gets low!!! Works kind of neat, You can hear the low battery beeper from way up, gives you time to get the plane down when you hear the beeping.... Works great for the price, am very pleased....
http://www.aeromicro.com/Catalog/gws_be-found_aircraft_beeper__futaba__1500029.htm



Carl

[aeajr]

Thanks for this GWS finder. I had not seen this one. Looks OK.

Where do they recommend it be installed?

What kind of plane do you have it installed in and how far away can you hear it? Did you test it in the air for sound carry?

The Air Alert and several of the others have a cylinder on the board which has the beeper. You can put a hole through the plane and pop this piece out, or you can just mount the whole thing on the outside.

From the inside of my Spirit glider, mounted under the canopy, I can only hear the Air Alert for about 30 feet on the ground. In the air I can hear it maybe 50 feet.

I am sure if I mount it through those ranges will tripple.

[fdisk]

I had a freak battery ejection over the weekend. It reminded me that I still hadn't made my batteries visable with color or a streamer. It also punctuated my need for a self powered locator. Does anyone know of a locator that is self powered and will beep if it gets unplugged from the rx?

[aeajr]

Originally posted by fdisk
I had a freak battery ejection over the weekend. It reminded me that I still hadn't made my batteries visable with color or a streamer. It also punctuated my need for a self powered locator. Does anyone know of a locator that is self powered and will beep if it gets unplugged from the rx?

I had not thought of hte streamer idea for the battery packas. Great idea!

This is not the usual locator, but this is the one I use on my Aerobird when it is windy out. Doesn't connect to the receiver.

http://www.keyringer.com/

Find the plane 5 miles away
http://www.texastimers.com/helpful_hints/walston/wal_cover.htm



Circut design you could build yourself and put on separate battery (http://www.geocities.com/andre25ca/anglais/electronics.html)

Circut design for another locator (http://www.ncws.com/rcrock/locator2.htm)

[fdisk]

That keyringer looks useful, unless everyone at the field had one. :D

I haven't checked out the rest yet, but thanks for the alternative options!

[erashby]

The DigiAlarm says that it should not be used with battery packs of more than 4 cells.
Does that mean that it is for gliders only?
Or can it be used in electric planes with 10 cell packs sinced the BEC drops the voltage down?
How do you know that the Lost Model Alarm at Windrider is the DigiAlarm?
Just because it looks the same?
What about the DIY LMAs can they be used with a 10 cell pack?

[gregw]

Originally posted by erashby
The DigiAlarm says that it should not be used with battery packs of more than 4 cells.
Does that mean that it is for gliders only?
Or can it be used in electric planes with 10 cell packs sinced the BEC drops the voltage down?
How do you know that the Lost Model Alarm at Windrider is the DigiAlarm?
Just because it looks the same?
What about the DIY LMAs can they be used with a 10 cell pack?

I put my first DigiAlarm on my Combat Wing XE2.. It just plugs in line with one of the servos. Just don't put it between the ESC and the receiver and you will be fine.

As to how I know the Windrider LMA is the DigiAlarm, I bought one from Windrider to put in another plane and it functions exactly the same as the DigiAlarm that I bought from Canterbury Sail Planes.

[crvogt]

aeajr,

The GWS "Be Found" beeper has the speaker like a little tube, you could mount it inside and put the speaker through a hole in the fuselage. You can see it sticking out the bottom in this picture
http://www.grandwing.com.tw/english/product/aux%20circuit/befound.htm

I have one mounted on the outside of one of my planes, sound is quite loud, went down in the weeds, I closed my eyes, and found the plane about 100-150ft away. On one of my other planes put it inside, cuts the sound down still can hear it at 50ft.

I have it mounted in my Bluecor powered glider and can hear the beeper while in flight, up a couple of hundred feet....
http://www.fototime.com/inv/1C06298A7F25A22

Aslo mounted in my Lazy Blue park flyer just stick it inside, good enought to find the tree it goes into... hehe
http://www.fototime.com/inv/C56A3A76139FEBD

Hope this helps
Carl

[evan]

The "keyringer" seems like a simple yet elegant idea. Anybody have an experience as far as the range and loudness of this thing is concerned in field conditions.

I lost a plane a couple of months ago and after searching for about 3.5 hours in thick brush and thorny vines, finally found it. The darn thing was within 40 yards of the area I was combing through with only the tailfeathers sticking out of the brush 5 feet tall. With a LMA this would've been found in 30 mins. or less.

[fdisk]

crvogt, I'm curious about your glider. What wing worked better, the white foam or the bluecor?

[aeajr]

Originally posted by evan
The "keyringer" seems like a simple yet elegant idea. Anybody have an experience as far as the range and loudness of this thing is concerned in field conditions.

I lost a plane a couple of months ago and after searching for about 3.5 hours in thick brush and thorny vines, finally found it. The darn thing was within 40 yards of the area I was combing through with only the tailfeathers sticking out of the brush 5 feet tall. With a LMA this would've been found in 30 mins. or less.

I use the keyringer on my Aerobird. Since it doesn't have a receiver in the usual sense, there is no place for me ot plug in a standard locator. Here is a photo of how I mount it.

If the air is calm and with a clear sightline, I can activate the keyringer from about 150 feet. In practical terms, about 40-80 feet is more like it.

On several occasions I have found the plane, but the key ringer was knocked off the plane. However it still responded so I found the plane, then I found the keyringer.

[fdisk]

Double-stick tape is your friend. Long after it looses it's true stickyness it still provides an excelent non-skid surface for things that are held down by rubber bands.

[evan]

aeajr; thanks for the response. I fly at high altitudes and over heavily wooded areas and the unit might not be suitable for my use; wish it had more range but it's still very interesting.

The MARS looks interesting too, anybody know where you can order this thing. I hit the add to cart button on the supplied link and it was giving me a Zagi Fixx?

[aeajr]

I had the same problem with the cart link for the MARS. I send an e-mail to the webmaster about the broken link.

If you are flying expensive planes high over bad areas, you may want a Walston:
http://www.texastimers.com/helpful_hints/walston/wal_cover.htm

The guy at California Sailplanes claims this one can be heard from 100 yards. I haven't tried it.
http://www.californiasailplanes.com/Lost%20model%20alarm.html

[gregw]

Originally posted by aeajr

The guy at California Sailplanes claims this one can be heard from 100 yards. I haven't tried it.
http://www.californiasailplanes.com/Lost%20model%20alarm.html

I have two and from my experience, I would say that 50 - 75 yards is probably more accurate..

You can also buy same LMA from Windrider at http://www.windrider.com.hk/products/product.cfm?id=3

[evan]

The maximum operating voltage of the unit from California Sailplanes is 6 Volts (nice looking unit). I need something that will operate up to 12 volts that's why I was checking out the MARS unit. I fly EPP foamies and 1 electric sailplane using 7-10 cell battery packs.

[gregw]

Originally posted by evan
The maximum operating voltage of the unit from California Sailplanes is 6 Volts (nice looking unit). I need something that will operate up to 12 volts that's why I was checking out the MARS unit. I fly EPP foamies and 1 electric sailplane using 7-10 cell battery packs.

I have the DigiAlarm on a Combat Wing XE2 running a brushless Mega 16/15/4 on 8 cells.. The alarm will work if you connect it, either to the Receiver in a spare channel, or in line with an existing servo. Just DON'T connect it between the ESC/BEC to the receiver and you will be fine.

[Hippo]

The Digi-Alarm (formerly called the Pathfinder) and the Wing-Max mixer with LMA are both available at FoamFly too.

http://www.foamfly.com/customer/search.php?substring=lost+model+alarm

Since WindRider is offering theirs for $17 with shipping, I thought you guys should know I've created a coupon for you guys dedicated to finding your planes. On the shopping cart page enter "EzonersLMA" in the coupon box to get $2.50 off the Digi-Alarm. That brings your shipped total down to $16.85 if that's the only thing you buy.

I never believed that this thread would go into such depth, or that so many people were losing their planes out there. I'll do what I can to help.

Thanks,
-Dan

P.S. A quick look around, and I see that I'm the one out of date. Digi-Alarm is the current name, and Pathfinder is out. I've updated the site.

[evan]

gregw, thanks for the tip; I'll do that.

Dan, thanks for the heads-up and coupon. I ordered one to try out and if it works well, i'll order at least one more. I was also looking for a collet type prop adaptor 3.2mm with a spinner for a Mega 16-15 series motor but seems like you dont have it. If you do; just include it on my order and charge accordingly.

Thanks to everybody for the information. I learned a lot.

[aeajr]

Dan,

I had not seen the web site before. Thanks for the special offer. I ordered two of the model locators. I was planning on ordering one from another site for $20 +10 shipping. I got two from your site for under $30. Really appreciate your help.

[tim hooper]

Gents all,

It's been pointed out to me that there is some great info in this thread, and that it seems a shame not to share it with a wider audience.

In view of that I'm going to shift it sideways to the Modelling Science forum.

tim

[fdisk]

Thats great Tim. I was hoping for more exposure because I'd still like to find a non-DIY locator that has an external battery, can be remotely triggered and communicates with the plane's RX for signal and voltage readings.

[aeajr]

Well, I sure would never have found it in Modeling science. What Modeling science are we dicussing here. These are products you buy off the shelf.

If you want, put a link there, but don't move it there. It will get lost.

Whatever. :rolleyes:

[aeajr]

Today was wonderful.

Got to the field by 9:15. I put out the BIG hi-start to run some practice luanches with my new glider. I am totally new to gliders.

Made about 20 great launches over a period of 3 hours.

One flight almost ended in disaster. I went down in the woods. I heard it hit from the middle of the field. I was sure it was a kit plane again.

Changed to long pants and walked into the woods. I was no more than 10 feet in when I hear what I wanted to hear. Beep Beep ..... Beep Beep!.

The plane was about 150-200 feet into the woods, about 10 foot up in a tree. Not a scratch on it. I used my toss line and sinker to get it down. I could not believe it wasn't broken anywhere.

I LOVE THESE PLANE LOCATORS. Heaven knows if I would have found it as it was not near a trail and could not be seen from a trail.

Best $15 I ever spent!

[evan]

that's good news aeajr. Glad you found it.

[aeajr]

Originally posted by Hippo
The Digi-Alarm (formerly called the Pathfinder) and the Wing-Max mixer with LMA are both available at FoamFly too.

http://www.foamfly.com/customer/search.php?substring=lost+model+alarm

Since WindRider is offering theirs for $17 with shipping, I thought you guys should know I've created a coupon for you guys dedicated to finding your planes. On the shopping cart page enter "EzonersLMA" in the coupon box to get $2.50 off the Digi-Alarm. That brings your shipped total down to $16.85 if that's the only thing you buy.

I never believed that this thread would go into such depth, or that so many people were losing their planes out there. I'll do what I can to help.

Thanks,
-Dan

P.S. A quick look around, and I see that I'm the one out of date. Digi-Alarm is the current name, and Pathfinder is out. I've updated the site.

Thanks for the deal Dan. I received my new Digi Alarms. After testing them out I like them much better than the Air Alert. They are also louder than the Air Alert. These are what I will be recommending to my friends from now on.

[evan]

Got the Digi-Alarm last Monday from Dan of foamfly and installed it today. The alarm seems to be very well made and is miniscule; came with excellent packaging, instructions and a nice little note. Tested it (on the ground) and so far it works very well. Now I just hope the weather calms down around here and we'll give it a field trial without losing the plane (hopefully):)

[Hippo]

I haven't tried out too many of the other model alarms. (It's hard to lose a plane in my backyard ;) ) But I had the Digi-Alarms on display at the Toledo model show. I decided to demo it, and pretty soon had guys in a 200 foot radius checking their pagers, cellphones, and watches. Pretty funny. Loud too.

-Dan

[aeajr]

If you want to see how effective one of these is, turn on your transmitter, then your receiver. Now have a friend hide the plane out of sight in an inconvenient place. Make sure he knows where it is for sure, just in case. Consider this a game of model hide and seek. let him cover it and do whatever he likes to hide it short of damaging it. You might even send it in without the wings to make it that much harder.

Now, have him tell you the general area where it is....very general since having a model go down suddenly rarely results in a good spot on direction and range.

Go take a look. Spend what ever time you feel you need to make sure you can't easily find it. Now, turn the transmitter off.

If you are anywhere near the plane, you should hear it. You might even find that it is vey close to you and you never saw it.

Here is an article about a club that did just this.
Finding a plane (http://webhome.idirect.com/~arrowmfg/ELT%20Beacon_files/elb-revi.htm)


This could actually be a fun club activity to see whether these things are worth the price.

Clubs might even consider including one of these as a gift to new members as part of their initation fee.

[fdisk]

Two problems with this. Servo jitter resulting in stripped gears OR (in my case) no beeping because my berg RX fools the locator into thinking all is okay.

[evan]

Hi fdisk,

Have you experienced this phenomenon "first hand"?

Static tested the Digi-Alarm using a Berg 5 receiver on the aileron channel (1) with a Hitec Eclipse 7 QPCM (set on PPM) and it worked fine; no servo jitter and the alarm went-off once the transmitter was turned off. I'm thinking of using it also on a Berg MicroStamp when I get one. I havn't flown the plane yet and dont know how it affects it in-flight.

[fdisk]

Now I'm not sure...

I never got a chance to try the digi-alarm working because mine was destroyed by overvoltage. That ESC has been terminated, but I never got another digi. I originally guessed that one of the reasons I couldn't get it to work at first was due to the berg being silent (so I moved over to flawed hardware and fried it), but maybe mine was flawed to begin with. I asked someone to try the digi on a berg for me but I don't think I ever got a response. I'd love to hear first hand that it works.

[Hippo]

FDisk,

No, I never got around to trying it, but I just plugged it into my Berg-4 here, and viola! It beeps. So, I guess theres more to it than just a wiggling signal.

I still haven't tried it on the M5, but it looks good. What the hell. Hang on....

....

Okay, it works there too. No servo jitter, plenty of loud beeping. I would recommend pointing the speaker out through a hole. Jammed down in the foam it was somewhat quieter.

Sorry it took so long.
-Dan

[aeajr]

With the beeper inside a balsa glider, I can hear it from 100feet+. Clearly if you put it through or near a hole it would carry even further.

I would imagine inside a foam plane it would be very surpressed. You would almost have to put it by a hole in the fuse, or mount it into the fuse.

There are other models that are flat, like the Air alert so you can mount them on the outside of the plane. Then you can probably hear them 200+ feet away.

[fdisk]

I bench tested everything so there was no muffle problem. I have no explanation as to why mine never worked. Just my usual luck I guess.

[aeajr]

Maybe that plane was like a naughty little child. It wanted you to look for it, but not find it too fast.

Kids and planes can be like that. We love them, but sometimes they can be quite infuriating.

I hope your plane never gets lost, your battery never runs low and you never have someone else sitting on your channel.

[evan]

Hello to all,

I am elated to inform everybody that the Digi-Alarm works well with my Berg 5, after 2 days of testing or approximately 3 hours of flying time interrupted only by battery changes and common sense. I have no problem recommending it to everybody who has been following this thread.

I will order more and give one to a friend who lost his plane a couple of weeks ago. We looked for it today for about 2 hours without any luck through thick forested areas covered with weeds, brush, vines and thorns. It was a major pain in the neck trying to cut your way using a machete and getting bitten by bugs of all sorts. Hope this never happens to any of us.

[aeajr]

Thanks for the field report and the practical example of how it would have helped your friend find his plane. I am sure he will really appreciate the gesture.

Safe and happy flying!

[fdisk]

I've lost two. One might have been found if it had a LMA on it. That one taught me that an LMA is important. The other was lost with its LMA, but far, far away where it would never be heard. I even drove around with my head out the window but I never heard anything. That one taught me to respect the wind and thermals.

Thanks for the report on the Berg/LMA working !

[KreAture]

After loosing my plane into a forrest for a distance, and having incredible luck in finding it again I had learned my lesson.
So I decided to make my own locator.

I dubbed it WIMP (Where Is My Plane?) and my goal was to make it insanely light. I ended up using a microcontroller instead of a timer as it ment few components and light weight. I also did it surface mount because I hate drilling holes... SMT also makes it lighter.

Here's the result:
http://www.unixcore.com/~kreature/images/wimp/wimp_1.1_05.jpg

Some specs:
- 2 power sources. RX and seperate battery!
- Can drive buzzers up to 30-40mA
- Very light! (Board + wire = 1g !!!)
- Low power drain. Uses 1mA when not beeping.
- Semi-smart. (It can differ between a lot of noise in signal and no signal at all. and beeps accordingly)
- Uses 25% duty cycle on beeps to quadruple battery life and make signal more audible.
- Cheap! I buildt mine for about $5 !

I had sooo much fun making it :)
Will be posting full info with partlist, PCB mask and software for controller. Everyone should have one :)

[aeajr]

That Digi-Alarm is such a great Plane Finder/battery monitor/

I was flying my Spirt sailplane today in gusty wind. On one landing I dropped the plane softly into some high grass and bushes about 100 feet in.

I though I was walking straight to it ,but the beep beep showed that I was about 20 feet too much to my right. I would have walked right past it and never have seen it.

Great device.

[erashby]

Originally posted by KreAture
...
So I decided to make my own locator.

I dubbed it WIMP (Where Is My Plane?)

- 2 power sources. RX and seperate battery!

Will be posting full info with partlist, PCB mask and software for controller. Everyone should have one :)

What voltage does the second power source need to be?
I have used another LMA, but when the battery is ejected, as it often is, then you are just out of luck.

I look forward to the info. I am already to etch some boards.:)

[KreAture]

The second power can be anywhere from 6-26 Volts. Max 40mA would be drawn.

My plane always ejects it's battery to. It's more by design really as the battery is 60% of the weight. Thus ejecting battery removes a lot of energy from the crash...

I redid the PCB and software today to fix a problem with the circuit not always starting. It now starts all the time and it gives a beep to tell you it's ok.

Oh, for those wanting to build one:
http://www.unixcore.com/~kreature/files/wimp_1.2.zip
That contains all you need. (Remember: Personal use only. No comercial production without my written permission. Making a board *free* for a friend is ok though.)

[evan]

Reviving this thread with some real-life experience with the LMA today.

I was able to thermal my Spirit today and after about 12 mins. I got a little nervous since the plane was getting very small due to the distance and not altitude (not specked out but close) so I decided to bail-out of the thermal and bring it back. To make a long story short I landed about 50 yards short of the field where the forest of trees, vines, thorns and everything that loves to hide planes are (for a total flight time of more than 18 mins.). When I got close to the area, I turned off my transmitter and the LMA started beeping. I found and retrieved the undamaged plane in less than 20 minutes. It would have taken me at least a few days to find it if it were not for this gizmo. It was located deep in a valley like portion of the woods surrounded by vines, thorns and rut's that were thigh deep, and the plane was up on a young tree that I shook vigorously before it let go of the plane (got lucky with the catch). Moral of the story: Use it everytime cause it's just a matter of time before you get a brain-fart like I had if you fly ofter enough.

[aeajr]

Evan, that is a great story. Which Lost Model Alarm are you using?

[evan]

I use the Digi-Alarm from www.FoamFly.com. Dan has a coupon code in this thread and I hope it still works so somebody can use it. I liked how it worked before this happened and I obviously like it a heckuvalot more now. BTW I have no affiliation with FoamFly whatsoever:)

[aeajr]

Yep, that is the one I use and is the one I now recommend to everyone.

The cupon has expired, but I have two more on order. Their price is still good. I have no affiliation either.

[Hippo]

The Digi-Alarms are out of stock right now. Thanks in part to you guys. I should have more soon, and when I do I'll re-instate the coupon here for all of you.

Thanks again,
-Dan

[lad3]

I'm new to all this, but since I lost my $300+ customized Photo Sky Surfer paraplane a year ago (on MY birthday, no less:( ) I figure I need something like this before my new parts arrive.

Can the Digi be used on any model, w/o servo mixing?

[aeajr]

It can be used on any model that uses a standard 72mhz receiver, either AM or FM. Servo mixing does not matter. I have used it on models with and without mixing. Works fine!

It can either be plugged into an open channel port on the receiver, or, if you don't have an open port, you plug the digi-alarm into the port and plug the receiver into the digi alarm.

[lad3]

In other words, I can hook this into any servo port on my receiver, and then link the servo to it (or do I need a Y cable?). If I use a servo port (instead of the throttle) I don't have to worry about the total amps going thru?

[aeajr]

I don't think it likes the throttle port, but I am not sure if I ever tried it. Sounds like you have used the Hobbico Air Alert. That one wnats to be on the throttle channel. It is really targeted to at electric powered planes.

Digi-alarm does not need a Y cable.

[Jim Poor]

I recently read about a small two way radio that has a GPS locator built in. You can get the location with a matching radio. A little big/heavy for some of the planes out there, but not so bad for some of the large pricey ones.

[aeajr]

Jim,

You might be thinking of the Walston system which puts a transmitter in the plane that can be tracked by a radio direction finder. Pricy, but effective over very long ranges, measured n miles.

I think this is the link:
http://www.texastimers.com/helpful_hints/walston/wal_cover.htm