Geoff, K6TFZ, wrote: I have noted by my own observations and comments of others some confusion as to exactly what colors are being observed on small parts, usually resistors and RF chokes...Incandescent lighting seems to be the least accurate for determining the correct colors, particularly yellows, oranges, and browns. Many times I have used sunlight (if available) or sought out a fluorescent lamp (cool white with at least 5200K temperature) to properly interpret colors. When in doubt, I use a meter to confirm the value.
------------------- Yes, reading color bands is a growing problem and lighting plays a huge role, especially as the color bands are made narrower and narrower on tiny parts. Incandescent light is very strong at the red end of the spectrum, making reds more pronounced and blues look weaker. Fluorescents have gotten a lot better in recent years, but all I have seen still have a discontinuous spectrum (some wavelengths where they produce no light at all) and a huge peak in output in the green part of the color spectrum. That can make gold look yellow, for example. The problem is that our eyesight has an automatic process that always assumes the light we have is white, and all colors we see are adjusted accordingly. When the source light is not uniformly "white", all the colors we see are shifted accordingly. Sunlight is ideal, but most of us build indoors and at night! I use a good magnifier to see the colors as clearly as possible and, if in doubt, check the part under both fluorescent and incandescent light. I also check a lot of resistors for value - especially the ones with blue bodies. The body color further obscures the color of the bands. Inventorying is also an excellent idea. One can establish which part is which by a process of elimination - matching up those that are obvious and then sorting out what is left while referring to the parts list. If a color is still in doubt, finding a known sample of the color often helps as I suggested with chokes recently where a gold strip looked yellow. Comparing that part with a similar part - especially with the same body color if available - that has a known yellow stripe will often make the difference clear. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [email protected] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
