FT-726R meter lamp (and why you should replace yours)

Aside

As the owner of 4 FT-726R’s I’ve slowly become familiar with some of the quirks and problems with these rigs.  Here’s one of the first things I do when I pick up one of these as a project radio – replace the incandescent meter lamp with Led’s.  And here’s why.

Just about every 726 I’ve seen has at least a little discoloration from the heat of the incandescent bulb.  Let it go too long, or leave your rig on 24/7 and you can see what happens.  These two meters are out of a rig I picked up on eBay as non-working and it must have been left on continuously, maybe for packet radio, because these are the worst I’ve seen.  Anyway, I did some experimenting with different led combinations and thought I’d post the results.

First, to get to the bulb you will have to remove both the top and bottom covers and the two top screws on either side of the face of the radio.  The whole front control panel of the radio will then tilt forward giving you access to the back of the faceplate.

Here’s the bulb location.  It just twists out, and in fact the circuit board can just be unclipped from the meters.

Original bulb and bulb “hood”.  Be careful taking the hood off, it may be somewhat fused to the bulb.  I had to use a drop of soapy water and toothpick, working my way around the rubber to get it to release from the bulb.

Here are some pictures of the different color LED’s I tried that I had in the parts bin here.  A single 5mm superbright led worked ok but I got better light distribution with dual 3mm.  I think that a couple of surface mount superbrights back to back, maybe 3528 or 5050 size would work especially well.  I’m going to give it a try on the parts rig I just picked up.

Bare superbright’s :

With bulb cover :

Green :

Blue :

Warm :

Warm with bulb cover :

This last one (dual mini superbright with cover) is the one I went with, even though it looks a tad green in the picture.  To me it looked the best out of the lot and was the closest match to the original incandescent. I inserted them into the meter backing, slid the small circuit board over the leads, and wired them in series to the board with a current limiting resistor to ground.

So there ya go.  I can leave the radio on as long as I want with no worry about the meter face starting to discolor from the heat of the incandescent bulb.

73, Ron