[Premium-Rx] lamp replacement

[Dave]

Don't do what I did...  I replaced the lamps with surface mount white LED 
strings mounted on edge (so as to shine into the acrylic) with a surface 
mount resistor for each string.  I used a good amount of these LEDs but 
still was way under the current drawn by the lamps.

Here's where the fun begins... The first time I turned it on, I was nearly 
blinded by the amount of light coming from the LCDs.  The radio is 
impossible to use right now unless you're wearing welding goggles.  I'll try 
to post a photo since it's pretty funny now.

I'll need to put a series resistor in the 15V line to the PCB so the 
receiver will become usable.

/Dave

> Jim Garrison wrote:
>
>> How easy?/How difficult?, and How cheap/How expensive?
>>
> If you are talking about leds which are found in the later version, they
> should not ever need replacement. If you are talking about the
> incandescent filament bulbs found in the early version then some or all
> will almost certainly have died by now...
>
> You can buy a replacement led board kit for the old version, I'd guess
> around $50, and this is fairly easy to install in the old version, but
> may require some machining of the acrylic spacer round the windows for
> the leds to fit.  I have found it easier to fit little surface mount
> leds (side firing yellow ones by Panasonic) on 1/8th inch wide strips of
> pcb board material, after removing the bulbs from the board.  They are
> connected in series in groups of 4, each fed with a 180 Ohm R.  8 above
> and 8 below each display.  Little slots are cut in the pcb material
> under each led.   The original tracks are used as supply busses and the
> strips can be glued, but also are held in place by the Rs and the ground
> returns.
>
> I got the leds from digikey, buy a few extra, as they have a habit of
> jumping away and getting lost...  This is actually more complicated to
> describe than to do.
>
> I have also fitted led lighting to one of my RA1792s, using a similar
> approach, a big improvement over the original which had no lighting...
>
> Good luck,
> Dan
> ac6ao / g3ncr