by Bill Cooke
Mention Estes to a rocketeer these days, and you usually get a smirk; they are famous for Ready-To-Fly (RTF) and other easily built low power kits. Not much thrill to many in flying birds using 13 mm, 18mm, and 24 mm motors (1/4 A to E impulse). But that’s changing… Read more
by Daniel Cavender
Last year, the field at Manchester, TN was planted half in sod and half in corn posing certain logistical challenges regarding recovery. There were several rockets that were lost in the tall corn and never recovered. One rocket made its way into an unfortunate combine and did significant damage. That issue is being resolved, and to our benefit, the field is all sod this year. HARA is implementing some new range safety practices to mitigate any further such incidents, but good launch site stewardship is the responsibility of every flyer. All flyers with rockets built using fiberglass, metallic, and other dense materials may be asked to outfit their rocket with a sonic beacon (if not already equipped with GPS or radio beacon). To help flyers find these beacons, this product review will examine two products: the LG personal security keychain alarm, and the Adept SB1 sonic beacon.
LG Personal Security Keychain Alarm
The LG keychain alarm is a very cheap and very loud device that can be quickly pressed into service as a sonic rocket recovery beacon. The alarm needs to be taped to the shock chord. The trigger device is a pull pin that takes about 2 lbs of force to trigger. HARA President, Ray Cole, flew one of these beacons at the March launch and it worked great. They were on sale for $4.95 at Lowes. The batteries are replaceable and the case is robust and provides protection from moisture and BP residue. At $4.95, this is a piece of insurance that will pay for itself time and time again.
Adept SB1 Sonic Locator Beacon
The SB1 is a small 90 dB sonic beacon designed for rockets. It can fit in the body tube of a 29mm rocket. The trigger device is a jumper tied to the shock cord that pulls off of two wires on the back of the SB1.The SB1 needs to be taped to the shock cord against the trigger and jumper. This is a poor design and did not work too well in the field. The jumper fell off easily during packing. The open unit made it prone to damage from the littlest amount of moisture or BP residue. Compared to the $5 option from a hardware store, the SB1 did not hold up.
by Daniel Cavender
The Perfectflite Stratologger combines the best features of the MAWD and HiAlt45, and offers greater programmability, data storage, and reliability. Those familiar with both the MAWD and HiAlt45 will have an easy time transitioning to the SL100. The SL100 is the same size, and has the same mounting holes pattern as the HiAlt45. The SL100 can operate up to 100,000’ MSL, and temperatures approaching -40°F. The SL100 records, altitude, temperature, and battery voltage at 20Hz for 9 minutes a flight, and can store flight data for 31 flights (> 55 times the MAWD). The SL100 has a telemetry output for real-time data in flight with your RF link. Precision sensor & 24 bit ADC yield superb 0.1% altitude accuracy (5 times the MAWD). The SL100 incorporates a post flight locator siren to aid in locating your rocket. An auxiliary output allows you to install an amplified external beeper.
At start up, the SL100 reports currently selected program preset, main parachute deployment altitude, previous flight apogee, and lastly, battery voltage, then lastly continuity by beeps.
The Stratologger seems a superior altimeter and at $20 cheaper than the MAWDs, which are now discontinued, it seems a good bargain for the capabilities. Thanks to the Perfectflite team for again building a quality, reliable, affordable altimeter.