Excellent!! Thanks!! Radio Shack is still barely alive in Mora, MN. And Jameco Electronics has (had) great catalogs that cover a lot of entry level electronics. DigiKey will overwhelm many, but is certainly a great place for the experienced. Ax-Man is OK, but electronics technology is worth getting right. As you say, any 100 ohm resistor could create a problem. Doug Reed wrote: > Yes, the Ax-Man stores are the place to look if you don't want to ask > someone to mail it to you. I believe there are 3 or 4 stores around > town. The only stores I am familiar with are in St Paul and Fridley, > but I thought there was one more in Bloomington. > > The color code for 100 ohms is brown-black-brown. But 100 ohms is too > low for testing a 9V battery. 100 ohms is fine for testing 1.5 volt > batteries at about 15 milliamp current load which is within the > capability of all AAA or larger batteries. > > But 100 ohms will attempt to draw about 90 milliamps from a 9V > battery. Most 9V batteries are rated for 50 milliamps maximum load. > Your 100 ohm resistor will tend to suck them down so they all fail > your test. For a similar test effect, you should use a 1000 ohm > resistor, perhaps even higher, up to 3000 to 5000 ohms so the load is > proportional to the battery capability. > > So when you are looking for the resistor at Ax-Man Surplus, the 100 > ohm resistor should have Brown as the first band, black or brown or > red for the second band, and Brown again for the third band. The bands > are counted with the first band closest to one end. > > The 1000 ohm resistor would have the third band colored Red instead of > brown. Since we don't care exactly what the value is between 1000 and > 5000 ohms, the first band can be any of Brown or Red or Orange, or > Yellow, and we don't care at all about the second band color. > > And I suggest that you look for a resistor that handles one-half watt > dissipation or more. Your batteries should never approach that but the > larger physical sizes are usually less likely to break from lots of > handling. A half watt resistor is physically about 1/8" diameter and > 1/2" long with leads about 1.5" on each end. > > The size you pick isn't really critical, it is really just for ease of > handling. You will probably find multiple examples to choose from, I > just suggest you don't choose the smallest size you find. Any resistor > larger than 1/2 watt will also work of course, if that is what you > find or want. The much larger watt values usually have the resistor > value simply printed on the side. > > And of course buy more than one of each for when you break or loose one. :-) > > Good luck. If my description isn't enough to work from, you can easily > find web pages that explain the resistor color code. And you can > always bring your voltmeter to the store and use it to check the > resistor value before you buy. Or buy a handful of different values > that have brown or red on the third band and check them at home. No > matter what you choose to do, the parts will probably cost less than > the gas to get you to the store. > > Doug Reed. > North St Paul. >