AOR 8000 Light

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danesgs

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May 21, 2008
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Leesburg VA
Has anyone ever replaced or improved by replacing the backlight in the 8000. It is way too dim to be usable except in complete darkness.

KJ4DGE
 

TassieJay

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Apr 12, 2012
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Australia
Yes! Here's an excerpt of a review & modification how-to that was hosted on a friend's website, that has since disappeared.


Changing the back light colour LEDs:

Difficulty: moderate.

How cool would an AR8000 look with an ice-blue back-lit screen & keypad? There's a wee bit of a problem with this. On the AR8000, each back-lighting LED is powered in pairs, in series, and the voltage for driving the LED pairs comes from a dedicated 4.5 volt regulator, which means each LED will receive 2.25 volts – ideal for running green, yellow, orange & red LEDs. However, this rules out the use of blue & white LEDs with their higher typical forward voltage of 3.6 volts. That would require the use of a 7.2 volt regulator – and the TK112xx series of regulators used only go up to 5.5 volts. Besides, the battery voltage from 4xAA NiCds means you should only count on 4.8 volts being available at most. So this restricts your colour choices to: green, yellow, orange & red.

The original surface mounted LEDs, SLM-13MW types, are rated at only 2.5mCd at 10mA, and one user described the back lighting as 'wimpy'. You can most definitely find brighter LEDs than that for the same current draw. Replacing the keypad and side panel LEDs with brighter types is easy – if you're used to working with surface mount devices – but the display 'side-looking' package of two LEDs in the one physical device (SLE0022) is a bit harder to replace; all I did was to solder some SMD LEDs on their sides – one LED at each end of the lands left by the SLE0022, and soldered a short link of wire between the two LEDs to connect them in series. This provides the spacing between the LEDs required to achieve even illumination of the LCD display, as well as being a good practical way of fitting these LEDs.
AR8000_LEDmod.jpg
 
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