From att!compuserve.com!73163.113 Wed Oct 12 17:11:05 1994 From: Bob Littlefield <73163.113@compuserve.com> To: Subject: Doug's Catalog Content-Length: 18288 X-Lines: 460 --- Forwarded Message --- #: 266 S0/CompuServe Mail [MAIL] 30-Sep-94 14:47 EDT Sb: d:\amipro\docs\cat.asc Fm: DOUG PRATT [76703,3041] Pratt Hobbies, 2565 John Milton Drive, Suite 201, Herndon, Virginia 22071 Phone 703/689-3541, voice and fax; CompuServe 76703,3041 Thank You for inquiring about our products! Pratt Hobbies was created to develop new and exciting products for rocketry enthusiasts. Our ECS-2 radio system is in full production, after over two years of development. We've made substantial improvements in our HeatShield line of flameproof parachutes and Parachute Protectors. We've been able to lower the price of our Kevlar Safety Line shock cord backup material and our Pad Blanket grass fire preventer. And our new Power Pack and Launch Box are already proving to be very popular! If you're new to rocketry, let me recommend the book "Basics of Model Rocketry" as a guide to getting you through the early stages. Recently revised to include modern technology like high power and reloadable motors, it's a bargain at $8.95. If you want your copy autographed by the author, just ask! The very best way to learn about and enjoy rocketry is by finding other rocket modelers. You don't have to look any farther than your home computer for one of the biggest rocket clubs in the world! The ModelNet service that runs on CompuServe has very active message sections and libraries devoted to Sport Rocketry, as well as official participation from the two national groups, NAR and Tripoli. We will be happy to send you an introductory CompuServe subscription, which includes a month of free CompuServe access and a usage credit for the "plus services" like ModelNet. Just check the box on the order form. We wholeheartedly support the National Association of Rocketry and the Tripoli Rocketry Association. If you are not a member of one or both of these groups, you're missing out on the best part of the rocketry experience. NAR and Tripoli fight for our rights with Washington regulators and work to make our sport safe and secure. They deserve our support. If you want more information on either or both organization, just check the boxes on the order form. Best regards, Doug Pratt Control Your Recovery By Radio! ECS-2 Two Channel Event Control System (see photo on cover) A custom-made radio system designed for rocketry! The ECS-2 is designed and built by Ace RC Inc. of Higginsville, Missouri, in collaboration with Pratt Hobbies. Ace RC is the only American manufacturer of radio control systems, and has a 40-year reputation as the best in the business. The ECS-2 uses a tone-coded system that is virtually interference-proof. The receiver and battery pack are small and light, making it easy to move them between models. Receiver power is supplied by a special Ni-Cad battery pack (charger included). The receiver itself is sealed in plastic, and measures 1 1/2 inches in width. The system can be easily fitted into most rockets with 2 inch or greater diameter. Two "safety harnesses" are included with the ECS-2. These are cables that connect to the receiver outputs; your ejection charge unit plugs into the safety harness. Each harness has a jack in the middle. The harness is installed in your model by drilling a hole for the jack and fitting it with included hardware. A safety disconnect plug is kept in this jack while the rocket is mounted on the pad. A test light inside the plug will light when the channel is activated, as a continuity check. No power can reach the output of the safety harness as long as the plug is in place. Once the plug is removed and the system is armed, pressing the transmitter button delivers 6 volts to the selected receiver output. MOSFET technology prevents accidental activation; the ECS-2 is flashbulb safe. Prototype receivers have been range tested to over 5000 feet on the ground; range in the air will be greater. Range really iisn't as important as you might think; after all, if your model flies out of range, it'll fall back in. Typically, the ECS-2 will go into a model that has a payload section. The unit mounts in the bottom of the payload section with Velcro for positioning, and a simple bulkhead or cap to keep it in place during flight. A standard ejection charge unit (available from North Coast Rocketry and other suppliers; we sell the reloadable units made by Robby's Rockets) plugs into the output. In flight, the rocket motor's ejection charge deploys a streamer, giving the rocket a speedy descent from high altitude with little wind drift. When you're ready, hit the transmitter button, and eject the main parachute from the rocket's payload section. Of course, our HeatShield parachutes and streamers make installation simpler, since they don't require wadding! The second channel can be used to fire a second stage, air-start strap-on motors, or kick out the streamer. We've flown prototypes with reloadable motors, and left the ejection charges out of the motors, controlling all phases of recovery from the ground. However, we recommend using the motor to deploy the drogue; that way, you have redundancy in recovering the model. You can also plug the accessory ALB-1 Locator Buzzer into the spare channel; when you push the transmitter button the ALB-1 emits a loud noise, to help you find your model in tall grass. A buzzer that is constantly on can blend into background noise; being able to pulse the buzzer will help you find your model faster. The rechargeable battery pack supplied with the ECS-2 receiver is a custom-made five cell 150 milliamp-hour unit. We use the best quality Sanyo ni-cd cells. The included charger will bring the pack up to full charge in 16 hours, and will not overheat the pack if it's left on for a full day. We selected these cells because they are small and light, making them easy to install. They will run the ECS-2 receiver for eight straight hours and still pop a flashbulb. If you want to field-check the battery pack, make sure you use a battery meter that can apply a load to the cells, and is designed for five cell (6 volt) packs; most of the testers sold for RC airplanes are designed for their standard 4-cell packs. We recommend and sell the Ace Voltmaster 2; it's one of the finest ni-cd testers available. A simple relay unit will allow the ECS-2 to control camera shutters or other devices. Call us; we can make custom units for your special projects. ECS-2 Event Control System, complete $149.95 SH-2 Safety Harness, 2-pack $19.95 SP-1 Safety Plug with continuity light $4.95 DC-1 Deans connectors, male, 2-pak $2.00 BP-150 Ni-Cd Battery Pack, 6 volts, 150 milliamp/hours $20.00 BC-150 Battery charger for BP-150 $11.00 VM-2 Ace "Voltmaster" Battery Test Meter $48.00 LES-1 "Robby's Rockets" Loadable Ejection System $19.95 ALB-1 Accessory Locator Buzzer $21.00 New! Control your Impulse Veri-Fire launch system by radio! The "ECS-2 Cable Link" from Impulse Aerospace plugs into the base unit of the Veri-Fire launch system and one output of the ECS-2 receiver, allowing you to control ignition with an ECS-2 radio. Launch your models from half a mile away! ICL-1 Impulse Aerospace Cable Link $14.95 The Veri-Fire launch system from Impulse Aerospace is the finest relay launcher available. Circuitry actually measures the resistance of the igniters; it can tell the difference between a bad igniter and a short! We are proud to have the Veri-Fire system in our catalog. IVF-1 Impulse Aerospace Veri-Fire Launch System $94.95 Ni-Cd batteries are Better For Launching! Here's Why: Most igniters need a good pulse of volts at considerable current to ignite. Even flashbulbs and electric matches take more power than you might think. That's why the "standard" for high power ignition is 12 volts. Most ignition systems come with clamps to attach to a car battery; that's fine, if you have your car at the launch site! Many modelers use small 12-volt motorcycle batteries or "gel cells" (lead-acid cells with gelled electrolyte) for power. These work very well, but they have some bad habits. The worst one is their tendency to "sulfate" if they're not kept at peak charge constantly; an insulating chemical deposits on the battery's plates, ruining it. They're also quite heavy and can be cumbersome. Nickel-Cadmium rechargeable batteries have some distinct advantages over lead-acid batteries. For one thing, they can be stored at any state of charge for any length of time; just charge 'em up again and they're ready. They don't leak and they don't weigh a lot. Best of all, they dump everything they've got into a short...and an igniter is really just a short. I've seen tiny little 1/3AA ni-cd batteries, rated at 150 milliamps, put a whole two amps into an igniter. In fact, without some protection, nicads will dump their current so fast that they'll get red hot in the process! The big problem with nicads has been the price, as compared with lead-acid batteries. The cells I like to use, Sanyo 1300 milliamp sub-C size, retail for $5.50 per cell...and you need ten of them to make a 12-volt pack. Well, as luck would have it, I came across a supply of brand new Sanyo sub-Cs at a very good price, low enough to make it possible to develop launch systems with them. To top it all off, these packs have an internal circuit breaker that kicks in if the cells come close to overheating. They're perfect for our purposes, and I'm delighted to offer them to you in these two new products. The Power Pack 12 Volts and 30 amps of Ni-Cd power Charger Included! Catalog no. PP-12: $59.95 (see cover illustration) The Power Pack (catalog number PP-12) supplies an average 12 volts of power at up to 30 amps momentary current. It's the ideal power source for a relay ignition system like the Impulse Veri-Fire. In our tests, the Veri-Fire/Power Pack combination lit 10 thermalite/wire wrap ignitors so fast we couldn't get a stopwatch on it. The Power Pack comes in a custom high-impact plastic case. The top plate has a heavy duty on-off switch. The terminals on the bottom plate can accept standard banana plugs or can be tightened onto bare wire leads. The charger included with the PP-12 can bring the pack up to full charge in 12 hours. An internal thermal cutoff acts as a circuit breaker to protect the Power Pack from overheating. This can happen if the terminals are accidentally shorted, or if the Power Pack is overcharged. The cutoff will break the circuit when the cells begin to overheat, then automatically reset when they cool down. The PP-12 uses top-quality Sanyo 1300 milliamp-hour cells. They are capable of accepting a fast charge at a rate of 3 amps if necessary. Modern Sanyo cells do not develop "memory" and do not need to be deep-cycled. Each PP-12 is charged and cycle-tested here, to make sure the cells are properly matched and delivering their rated power. Best of all, the PP-12 sells for less than you could buy the individual cells for! The whole package, assembled and tested, with charger, is $59.95. Go Out to Launch with a self-contained, rechargeable ignition system! The Launch Box cat. no. LB-12 $89.95 (see illustration on front cover) The Launch Box is based on the PP-12 Power Pack, and starts out with all the features of the PP-12: ten Sanyo 1300 mAh cells, internal thermal protection, and a high-impact custom plastic case. We added a transistorized continuity circuit designed by our ModelNet friend Gary Crowell. It sounds a buzzer when you have a good connection to your igniter. The circuit uses a tiny current and is safe with flashbulbs and electric matches. The FIRE button on the Launch Box is really neat; it took me a long time to find the right one. It has a clear flip-down shield that prevents the button from being pressed accidentally. The button illuminates when the system is powered up, and gives you a hard, positive "click" when actuated. Like the Power Pack, the Launch Box has terminals that can accept either standard banana plugs or bare wire. The Launch Box also has a coaxial power jack for charging its internal battery pack. The included charger can bring the pack up to peak charge in 12 hours. To use the Launch Box, you'll need wire of a suitable length. We recommend inexpensive "zip cord" or "lamp cord" two-conductor wire. Attach alligator clips at one end for the igniter, and banana plugs at the other end for the Launch Box. There's no key switch on the Launch Box; when you're hooking up the clips to your igniter, the Launch Box isn't even plugged in. In our tests, we flammed five thermalite/wire wrap igniters simultaneously through 300 feet of lamp cord with a fully-charged Launch Box. It'll fire single standard igniters all day long, then recharge overnight and be ready for the next day. For large clusters and serious models, we recommend a relay system like the Impulse Veri-Fire. For everyday use, you can't beat the convenience and simplicity of the Launch Box. Never Use Wadding Again! HeatShield Parachutes HeatShield Parachute Protectors Why bother with recovery wadding? Just use a parachute made from cloth that doesn't burn! Our HeatShield Parachutes are made from bright yellow Nomex (r) cloth, rated to 600 degrees continuous or 2000 degrees momentary heat. In our tests, HeatShield chutes and streamers have been ejected over 30 times without showing more than a few dark streaks and stains from the black powder ejection charges. HeatShield Parachutes are hemmed with 80-pound Kevlar (r) thread, and use 2000-pound Kevlar shroud lines. The lines are bar-tacked to the hems. To fail, they would have to pull out the hem and a doubled layer of the cloth, or exceed 2000 pounds of force on the lines. They're strong! Available in three popular sizes. HeatShield Parachute Protectors are recovery wadding that you don't waste with every flight. They stay with the rocket, protecting your conventional plastic or nylon parachute from the ejection charge. The small Protectors (catalog no. HSPP-1) are designed for Estes, Quest, Custom and other models that have body diameters of up to 2 inches. Simply slide the grommet in the Protector down your shock cord before attaching the nose cone and parachute, or tie the Protector to your shock cord with a piece of shroud line thread. Pack it in the model before the chute, and use it over and over. Two Protectors are included in each package. The large Parachute Protectors (catalog no. HSPP-2) are 16 inch disks of Nomex cloth, hemmed at the edges. Each Protector has a loop of Kevlar cord attached to the hem. Simply slip this loop over your nose cone and shock cord, then stuff the Protector into the tube ahead of your parachute. HSPP-2 Parachute Protectors are recommended for models with body diameters from two to six inches. HSP-20 HeatShield Parachute, 20 inch diameter $8.98 HSP-36 HeatShield Parachute, 36 inch diameter $17.59 HSP-58 HeatShield Parachute, 58 inch diameter $39.98 HSS-6 HeatShield Streamer, 6 feet long $6.98 HSS-3 HeatShield Streamer, 3 feet long $9.98 HSPP-1 HeatShield Parachute Protectors, small, two-pack $1.98 HSPP-2 HeatShield Parachute Protector, large $4.98 Don't Burn Up Your Launch Site! Use the New, Improved, Thicker, Stronger HeatShield Pad Blanket ...and it costs half as much as the original ones! Catalog no. HSPB-60: was $39.98 now $19.95! The HSPB-60 Heatshield Pad Blanket is a 60 x 60 inch sheet of Nomex cloth, hemmed at the edges with Kevlar thread for strength. Spread it on the ground under your launch pad to prevent grass fires! Each Pad Blanket comes with loops in the corners and four stakes. Rocket clubs, call us for a special safety promotion deal on Pad Blankets. No More Separations! Safety Line Shock Cord Backup It works...and now it's 40% cheaper! Ever had a shock cord break, and watch most of your rocket hit the ground, while the nose cone and parachute sail off into the distance? Me too, and I decided to do something about it. Safety Line is 2000-pound test Kevlar (r) cord, the same cord we use for shroud lines on our HeatShield Parachutes. To install it, you order or cut a piece that is at least one and a half times as long as the relaxed length of the shock cord in your model. Attach one end of the Safety Line to the same mount as the shock cord, in the main body of the rocket. Now loosely spiral the Safety Line up the shock cord. Tie the other end to the nose cone. That's it! If your shock cord lets go, the Safety Line holds things together. Safety Line is available in three precut lengths. We'll also custom cut a length to your specifications. SL-5 Safety Line, five feet $2.00 SL-10 Safety Line, ten feet $4.00 SL-20 Safety Line, twenty feet $8.00 SL-C Safety Line, custom length $0.40 per foot I hate to admit it, but it's our most popular product! Pratt Hobbies T-Shirts proudly emblazoned with the legend: "As a matter of fact, I AM a Rocket Scientist." and a tasteful Pratt Hobbies logo at the bottom, on a top-quality ash grey shirt. $14.95 each available in Adult Large, X-Large, and XX-Large, and new Kid Size! Pratt Hobbies 2565 John Milton Drive, Suite 201 Herndon, VA 22071 703/476-0354 76703.3041@compuserve.com Distribution: To: Bob Littlefield > [73163,113]