Posted by
AA5CK on
Jul 13, 2006; 6:07am
URL: http://elecraft.85.s1.nabble.com/K2-backlighting-brightness-tp392084p392085.html
Hi Ron
I went through this a few weeks ago. After trying several different
value resistors in parallel with R 10 I ended up with a 39 ohm one. This
dropped the the total resistance to about 18 ohms and increased the
current from the original 24 mA to 34 mA. Still not as bright as #5523
but close. Further increase in current didn't seem to increase the
brightness much so I went with the 39 ohm resister but YMMV.
I don't know about LEDs dimming but an increase in current may shorten
their life. Hopefully 5 mA per pair won't have a significant effect.
Maybe we'll get a more definitive answer from the list.
This is really not a big problem and I am certain I would have never
noticed the difference in brightness had the two rigs not been setting
side by side and even then it took several days before I noticed it.
Good Luck....Ted...aa5ck
ron_w wrote:
>
> Both K2's go remarkably the same, but the older K2 has a noticeably
> dimmer display than the new one which raises the questions :-
> (1) Do the back light LED's dim with time? ......the older K2 *has*
> had a lot of use.
> (2) Would changing R10 to (say) 22ohms have any detrimental effect on
> the life of the back light LCD's?
> .
> Cheers.......Ron ZL1TW
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