Drake LED pilot lights

Next to Collins, Drake is probably the better of the old boatanchor rigs. Not better than Collins, just better than anything other than Collins.

One of the more annoying aspects of using older tube type equipment is maintenance. The equipment rarely needs maintenance but when it does good parts are difficult to find.

A dead pilot light is one of these parts. The rigs can still be used with a dead pilot light. The dial and meter can still be read but there is something depressing about a dark radio even if it is still working.

The last time I replaced the bulb was about a year ago. I found a #47 bulb at Radio Shack. A year later it is dead. The original bulb had lasted over 30 years but it was not purchased at Radio Shack.

Six months ago I bought an LED flashlight. A real bargain at $3.50 even if it did have a super stinky plastic grip. Yup, made in China and they probably made the grip out of hazadous waste. Took about two minutes to remove the grip and throw it away. The end result was a nice little flashlight sporting 20 high intensity white LEDs.

The 20 LEDs were all connected in parallel and powered off 4-1/2 vdc from three AAA cells connected in series. No dropping resistors or other parts.

The LEDs were easily removed as they were soldered into a circular printed circuit card. I first removed one ring of six LEDs.

These LEDs were wired in paralled and powered from the 6.3vac pilot light supply with a diode in series with one power lead and a 50 ohm 1/4watt resistor in series with the other lead.

The LEDs were bright enough to provide sufficient reflected light to evenly illuminate the white diffusion screen originally used in the R4C receiver.

The LEDs were mounted on .4 inch centers with the row of six centered on a peice of surplus circuit board which contained plated thru holes on .1 inch centers.

This board was then mounted to a copper bracket and attached to a custom made pilot light bracket. A third section of copper was used to tie the copper bracket and the aluminum pilot light bracket together.

The physical arrangement was such that the LEDs were aimed at the underside of the custom pilot light bracket. The underside of this bracket was covered with aluminum foil acting as a reflector. The dull side of the foil was used as the reflector because the shinnier side resulted in hot spots on the white plastic diffuser.

No attempt was made to use the blue filter originally provided with the radio. The white diffused light from the LEDs was perfectly adaquate and seemed to provide better visibility than when the blue filter was used. Without the filter the dial looked as though is was illuminated by a cool flourescent. Bright and readable. No need for any strange filtering.

The illumination for the meter and Xtal switch window was provided using three additional high intensity LEDs. The finished overall effect can be seen in the accompanying photograph.

Now to do the same thing for the T4XC. At present the transmitter has some sort of greenish filter and old incandescent bulbs. It will be good to get it upgraded and looking like a real match for the R4C.

My Drake twins will soon be twins again.

Those not willing to give up the blue light may be interested in using Blue LEDs. Note also that high intensity LEDs are also available in red, green, and yellow. When using colored LEDs there is no need for a filter.

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