# Rocket Locator

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#### cwbullet

##### Obsessed with Rocketry
Staff member
Global Mod
They are well built and work to fin a rock in a corn field.

#### kjohnson

##### mox nix
Very happy with my Pratt MicroBeacon. It's easy to use, and is loud enough to be heard if you get near where the rocket landed. Can be used in any sized rocket over BT-20, beeps and flashes as soon as you put in the battery. The warbling tone is very distinctive, we call 'em rocketeer annoyance devices if they are going off in the prep area.

Can't say I've ever seen one of the WeeBee's, it seems a little more complex (lift off detection, low light sensor,flash or beep, metal casing, etc) and at 6 times the price, it doesn't seem to be in the same category as the MicroBeacon.

kj

#### Marlin523

##### Well-Known Member
Thanks for all the input. I ordered a MicroBeacon.

#### DM1975

##### Upscalien
TRF Supporter
As cheap as they are, I figure I will buy a few of these as well to keep in the rangebox. Good insurance I suppose, especially now that I have a Black Hawk 24 en rout.

#### n5wd

##### Well-Known Member
Have you used one of these?
http://www.pratthobbies.com/proddetail.asp?prod=MB-12
If so, what do you think of it?
We found door alarms at Harbor Freight for about a buck each. A little bit of wire and tape to hold the magnet on until chute deployment, and you've got a very audible alarm! If the commercial one doesn't work out....

#### Gillard

##### Well-Known Member
i've been using the pratt microbeacon for a few years, a must when it gets to late summer and i'm flying in a corn field

#### n5wd

##### Well-Known Member
Is this the door alarm you use?

http://www.harborfreight.com/door-window-entry-alarm-94983.html

How exactly do you use it? How heavy is it? It seems kind of big.
Yep, that's the one - guess they were on sale when we found 'em.

It's about as big as a pack of chewing gum. I attach the main part of the unit to the eyebolt on the upper stage, and the magnet, which is held on by a strip of masking tape to keep the alarm silent until after apogee, is attached to the shock cord in such a way that when the cord pulls straight it'll pull the magnet away from the alarm, setting it off.

#### WillMarchant

##### Well-Known Member
TRF Supporter
I attach the main part of the unit to the eyebolt on the upper stage, and the magnet, which is held on by a strip of masking tape to keep the alarm silent until after apogee, is attached to the shock cord in such a way that when the cord pulls straight it'll pull the magnet away from the alarm, setting it off.
You can perform a similar thing with the Pratt module. Use a strip of plastic in between the battery and the spring.'

Unless you like the thing serenading you during flight preparations... :roll:

#### qquake2k

##### Captain Low-N-Slow
Yep, that's the one - guess they were on sale when we found 'em.

It's about as big as a pack of chewing gum. I attach the main part of the unit to the eyebolt on the upper stage, and the magnet, which is held on by a strip of masking tape to keep the alarm silent until after apogee, is attached to the shock cord in such a way that when the cord pulls straight it'll pull the magnet away from the alarm, setting it off.
I found this on Ebay:

http://cgi.ebay.com/Worlds-SMALLEST...ltDomain_0&hash=item53e12d40ed#ht_6470wt_1084

The "rip cord" feature would be ideal for rockets.

#### Winston

##### Lorenzo von Matterhorn
I found this on Ebay:

http://cgi.ebay.com/Worlds-SMALLEST...ltDomain_0&hash=item53e12d40ed#ht_6470wt_1084

The "rip cord" feature would be ideal for rockets.
Great find! I just ordered one of them both to use in rockets and to discover its pulsing circuit design. I've been looking for an extremely loud _3V_ piezo or dynamic annunciator and the large selections at both Mouser and DigiKey don't have anything that loud (although one can rarely take Chinese specs like "125dB" at face value) at that voltage. And all of the components of that alarm combined are cheaper, even including shipping, than most of the individual annunciators alone from Mouser or DigiKey.

#### jsdemar

##### Well-Known Member
Here's a listed with 37 of them, "Buy it Now" for $1.99 ($4.49 with shipping).
Just a follow-up to let y'all know these things work great. I ordered 4 and used one at NSL in my M-motor flight. I duct taped the unit to the shock cord and attached the pull string thru a quicklink. I shaved off some of the plastic on the pull tab to make it come out easier. It deployed with the main 'chute.

The rocket was about 1/2 mile out into the thorny 6ft mesquite bushes and I was about 1000ft off the line. The warbling sound brought me right to the rocket. A $5 located beats losing$1000 worth of rocket, 'chutes, electronics, motor casing, etc. Already did that once out there!

-John

#### qquake2k

##### Captain Low-N-Slow
Just a follow-up to let y'all know these things work great. I ordered 4 and used one at NSL in my M-motor flight. I duct taped the unit to the shock cord and attached the pull string thru a quicklink. I shaved off some of the plastic on the pull tab to make it come out easier. It deployed with the main 'chute.

The rocket was about 1/2 mile out into the thorny 6ft mesquite bushes and I was about 1000ft off the line. The warbling sound brought me right to the rocket. A $5 located beats losing$1000 worth of rocket, 'chutes, electronics, motor casing, etc. Already did that once out there!

-John
I just ordered two of them.