How many times have you hit the launch button, only to wait for what seems to be an eternity as an old battery tries to crank enough juice through an igniter to launch the rocket? 

The Pratt Hobbies Power Pack 12-volt ignition power supply can put an end to such experiences. It also can fire virtually any igniter you might care to use and will take much of the adventure out of clustering motors. 

When I built my launch system, I looked long and hard for a good power source. I wanted a rechargeable supply with plenty of power, but which didn't take up a lot of space and didn't cost an arm and a leg. For a while, I used four D cells inside the unit and an external jack to connect to car batteries. I searched for other options. 

The first Power Pack cost $59.95 and came in a plastic enclosure with a switch. The new PP-12B costs $24.95 and is somewhat different than the original. The 10 Sanyo sub-C ni-cad batteries are packaged in a flexible, plastic-like substance. There is no switch. 

I had considered buying a Power Pack, but didn't want to pay the original price. The introduction of the lower-priced PP-12B made the purchase feasible. The $24.95 includes a charger. If you're presently buying disposable batteries, it won't take long for this product to pay for itself. 

The Power Pack attaches to launch systems with two banana jacks. You'll need to modify your launch system to use banana plugs. If the system includes polarized electronic components - such as transistors, integrated circuits, capacitors or other such devices - you'll need to be careful about the polarity. My system uses an old-fashioned lamp continuity system, so polarity wasn't important. 

Although you're supposed to charge the unit for 12 hours after receiving it, I charged mine for one hour and then tried it on a MRC igniter. It worked instantly. I continued to charge the unit for the recommended time and then tried it on a series of igniters. I ignited electric matches, thermalite and some home-made igniters. In all cases, the igniter went off instantly. 

Without recharging it, I took it out flying. It's a small unit and fit easily into my range box. I bought a couple of banana plugs at Radio Shack and fashioned a plug-in connection to my launch system. I launched a three-motor cluster, using Estes igniters. Liftoff was instantaneous. I flew one more rocket and it too lifted off rapidly. 

The next day, I flew another cluster with three Estes igniters, and again, liftoff was immediate. I then pulled out an old igniter which had lost much of the igniter material off of the tip. I tried it on a single-motor rocket. The rocket did not lift off immediately; I paused, then hit the launch button again. The rocket lifted off. When I went to the pad to launch another rocket, I noticed that the igniter had actually melted into the plastic igniter plug. Apparently, there was so much current going through the wire that it became hot enough to melt into the plastic! 

I flew two more rocket using igniters that were in good condition. Again, ignition came with no delay. The launch system was going through 20 feet of 18-gauge cord. 

I am very pleased with the Power Pack. I now can launch clusters or high-power rockets without having to drag out an old car battery. It's cheaper than jury-rigging together two 7.2-volt RC car batteries and safer than using motorcycle batteries, which can spill electrolyte. Pratt Hobbies also believes the Power Pack is superior to gel cells, which can sulfate if not kept at peak charge constantly. 

The pack includes an internal overload switch to prevent damage if the pack is accidentally shorted for a long period of time. The instructions caution against carrying the Power Pack in a metal range box, since the two jacks could shorts through the metal, possibly damaging the ni-cad batteries. 

The Power Pack would seem to make an excellent choice for a relay unit - of course, since it cranks so much power, who needs a relay? Well, you do need one for certain igniters and for the most reliable ignition. 

Pratt Hobbies offers two related products. The Launch Box features the Power Pack and a flashbulb-safe continuity circuit with a shielded launch switch. There also is a higher-powered Power Pack with twice the number of ni-cad batteries for just $10 more. If you can swing the extra 10 bucks, you'll likely have all the power you could possibly want for rocket ignition. 

The Power Pack solved one of my ground support problems and I hope it can do the same for you. 

The Power Pack is available from various hobby stores or directly from Pratt Hobbies, 2565 John Milton Drive, Suite 201, Herndon, VA 22071 hone (703) 689-3541. Price is $24.95 plus shipping.