Cheap beepers (sonic locators)

[Fore Check]

Hey all-

Thought I'd give a try using the "personal alarms" available as a sonic locator device. Found a site with good prices and a nice product for rocket use.

https://www.streetdefender.com/cgi-bin/catalog.pl?catalog=0

I purchased a pair of black MC-231 alarms and got fast delivery and good email follow up after making the web purchase.

Here's what I got. It's 1.5" wide, so it should fit nicely in rockets with BT60 airframes and up. It already has two lanyards/clips, so no extra steps are needed to drill the alarm or wrap it with tape or tie-wraps or anything to attach it to the recovery system. When the black lanyard strap is given a light tug (thus removing the pin) it emits a SCREECHING warbling alarm. I'd say attaching the provided metal clip to a loop or knot in the shock cord close to where it exits the airframe, and clip the lanyard strap to the nose cone, and it's done. Provided the shock cord is longer than the the total length of the alarm, the nose cone at ejection should pull the strap/pin out of the alarm, sounding it at ejection. Then the alarm itself would be attached to the rocket airframe in the event of a separation.

(sorry about the poor focus... )

 

[Sailorbill]

They work great. Found a rocket laying in a Sorghum field. Could not see the rocket until you were on top of it and even with the locater you had to be in the same row to hear it.
I do replace the part that attaches the body of the alarm to the recovery harness with some heavy Kevlar thread. The little metal rings have been known to open up during an energetic ejection event. I have also tied and taped the beeper to the recovery harness for added insurance. We had a flyer who found the beeper but not the rocket. I have never seen a problem with the pull pin lanyard though.

 

[astrowolf67]

I've used some similar to these that I found at a local KMart store. I did drill a small hole in the case, and replaced all the lanyards with kevlar thread. They work great for locating rockets in tall grass as long as you have a good line of sight to your landing spot. The siren is loud, but, the sound can easily be blocked by tall grass, soy beans, ect. These things are also fun to hide behind your door, and set off as your wife opens it to come in the house :kill: I've only done that once

 

[lalligood]

Forecheck,

Thanks for the link. RadioShack no longer carries (at least in my area) the "blue egg" beepers & I've been wanting to get some new ones.

 

[Fore Check]

Originally posted by lalligood
Forecheck,

Thanks for the link. RadioShack no longer carries (at least in my area) the "blue egg" beepers & I've been wanting to get some new ones.

No problem. I too read about the blue Radio Shack eggs and made an effort to get some and couldn't. So, after much web searching, I found these. Thought I'd pass it along.

 

[Stymye]

It already has two lanyards/clips, so no extra steps are needed to drill the alarm or wrap it with tape or tie-wraps or anything to attach it to the recovery system.

I'm not fasmiliar with that model but make sure the lanyard connection is good strong and not going thru a thin area of plastic. I found that out the hard way and now re-enforce them if possible.

 

[Karl]

Hey Fore Check!

Believe it or not, we use these 'over the pond' too! Just a slightly different brand.

I have found many rockets in 6ft+ tall Rapeseed using them. I had one fall from 2000ft after tearing loose from the rocket, and it was still bleeping out its tone when I found it.

They don't seem to like hard landings though. I usually put abit of electrical tape over the battery connections to keep it in place. I've had the battery knock out of place on landing and turn the beeper off.

All hail the 140db beeper. Locator of all things rocketry

 

[highrolla7]

Forecheck,
These things work great! I have the blue egg looking one and used it (yesterday) Saturday at the Crown Jewel launch in Walcott. Attached it to the top of the piston (with the keychain part) and taped the egg part down the shock cord a bit. Loaded it into the PML patriot 1/4 and launched her up around 4400-4500 feet or so, used my stealth jr smaller chute so I would avoid the corn and it landed across the road in a small bean field (was my L2). Funny thing is, I could here the egg warbling up in the air as it was decending- very faint, but could hear it. Walked to the area, and it was yelling pretty loudly. These things are cheap and work great! The rocket hunter transmitter than BHP let me use beeped occasionally, but the egg was louder than ever!

 

[Stymye]

I had one land in a tree just warbling away!,...I heard more than one person say"somebody shoot that thing !" before the day was over..it was a good 500 yards away!

 

[astrowolf67]

Originally posted by stymye
I had one land in a tree just warbling away!,...I heard more than one person say"somebody shoot that thing !" before the day was over..it was a good 500 yards away!

In an orange and black V2? That thing wailed all day long!

 

[Chris B.]

Originally posted by highrolla7
Attached it to the top of the piston (with the keychain part) and taped the egg part down the shock cord a bit.

Taping the beeper to the recovery harness has always worked fine for me too. Since I took this pic I've started using a small karabiner to attach the pull-pin to the U-bolt instead of a keyring as it's less fiddly.

I also prefer to use the weight of the booster section to pull the pin out. I have found that the pin is secure enough to hold the weight of a 3" nosecone and I'm concerned this may prevent the beeper from working.

 

[highrolla7]

thats the same way I do it except its attached to my piston- same concept. the one thing I did notice about yours was it looks like the tape will cover the "sound hole". I wrapped mine and left the center hole open.