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LCD/S-Meter Backlighting
With the advancements in LED's, such as flashlights, Brake and Parking lights ect.., I have been getting a few inquiries about switching the Lamp to a LED for the radio S-meter backlighting. Untill recently, the "white" LED's had a rather narrow beam width (great for flashlights). What this did to the S-meter, was left a bright middle and a dark Circumference, great for S5 or S9, lousy for 60 over or 1.
There is a new White LED out now, Mouser PN 859-LTW-77HC4, and a Yellow LED (for the 275 series) Mouser PN 859-LTL1CHKSKNN, which has an impressive 140 degree width (45 for the Yellow, most are 30 degrees, 45 just gets the job done as seen in the Pic). 140 degrees for the white, is a little dim, but as you see in the pic's, it does a good job. I tried a 110 degree Yellow, but it was just too dim. The White works better for the yellow'ish backed meters than the black backed ones (the Yellow LED is too Yellow for HF base meters I think). I am going to stock the LED's, and install them for those who want it. :-)
If you do this yourself, be sure to use a series resistor, either the anode or cathode, doesn't matter. At 13v I found a 470 ohm pushes pretty good, a 220-270 ohm runs twice the current, but only about 25% more lighting, and takes it.
S-Meter Pic's

756/746/Pro's Backlighting Sometimes the backlighting transistor overheats (runs hotter the dimmer the backlighting is set to) and eventually the solder connections fail. This seems to happen more on the 746. I replace the device with a 2SB1202 (2SB1201 is stock) it has a little better spec's, and add a heatsink. So far no repeat failures.