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Old October 17th 05, 04:05 AM
Peter Maus
 
Posts: n/a
Default Ten-Tec RX340 meter lamp replacement

Telamon wrote:
The lamp burned out and instead of replacing it with another blue/green
bulb I elected to use LEDs. I sanded the surface of the LED case to
make the light it generated non-directional. I used three blue ones
from Radio shack 276-316 in a line in place of the bulb and outside
the meter case I used a resistor to limit the current. It looks pretty
cool but very "blue." Now that I see the result I'm thinking that maybe
white LEDs like a 276-320 would have been better choice as even the
white LEDs look somewhat blueish to me.

Anyone have any experiences using LEDs to replace bulbs on receivers?


Yeah, I used a blue LED to replace an incandescent on a Telefunken
HD5000. The device was behind a green filter. The result was very, very
blue. With no trace of green.

I went back to white.

I've also used white LED's, which created a heated debate here, to
replace the dial light on my T/O 3000-1.

The results are good. Covering the bulb with a thin tissue produced
better results than sanding. Abrading with steel wool produced the best
dispersion results.

I've also done some experimentation replacing the fuse type bulbs in
my Marantz 2218 with LED's. The results, so far, have been less than
exceptional. I tried replacing the stereo pilot on the Marantz with an
LED, but the incandescent was integrated into the circuit, so I need to
build a resistive network that emulates the incandescent in operation,
and tap the LED out of that.

Digi-key offers a drop in LED replacement for a number of bayonet and
screw in incandescents both A/C and D/C. The lighting circuits for both
my McKay Dymek AM-5 and McIntosh C-26 are odd values so a direct drop in
isn't available. And the Mc Kay rips the lighting voltage out of
another circuit, so draw, and drop will have to closely approximate the
incandescents.

Then again, I'll only have to do it once.

The upside of LED replacement of incandescents is two fold. The lower
heat generated has enabled me to restore some of the cosmetics which
were damaged by the heat. And pretty early in the life of the receiver,
at that. The purity of colors has made for some very striking dials. The
light blue accents on the tuning scale and the red accents on the
function indicators are visible from the street when the lights are low
in the living room.


Right now I'm looking at the bluest meter on the west coast and the
moving red needle looks almost iridescent.



Things with LED's can get pretty surreal when there are colors
involved. And the color gels in place for the incandescents, don't matter.