In "The Doctor is IN" (Aug 2003, p 53), we should have pointed out that the formula for the LC constant should be used with L in µH and C in µF (not H and F) in addition to f in MHz.--tnx Robert Crupi, NA6H
In "Hands-On Radio" (Mar 2003, p 64), the first sentence of the caption for Figure 1 should read "The common collector circuit," not "...common emitter..." It is, of course, an emitter-follower circuit and we labeled it incorrectly.--tnx Galen Tustison, W4WET
In "Solid-State Those Panel Lamps" (Sep 2003, pp 38-39), we neglected to talk about reverse voltage protection for the LEDs when operating from an ac source. The diode will be subject to about 9 V peak, when operated from a 6.3 Vrms ac source. LEDs will normally have a PIV rating of anywhere from 5-10 V and a back protection diode placed in series with the LED will ensure against premature failure. Another LED, back to back, in series with the first, will also work and both will then light on ac. Of course, if you are running these on dc, there's no problem.--tnx Roger Wagner, K6LMN