Tag Archives: MFJ-822

SWR Meter Bulb Replacement – Win!

I use an MFJ-822 SWR meter with my base rig and it has served me well. Only issue is the small incandescent 12V bulb burned out making it hard to read in a low light situation. I replaced the bulb with a white LED rated at 12V by MPJA. This did require a bit of careful surgery but was successful. One screw removed the case. The bulb is connected with a small Molex connector. The meter connections have to be un-soldered in order to get at the bulb. The meter movement is gently pried off the cover. Here it is disassembled:

Photo May 23, 3 20 57 PM

The bulb used in the MFJ meter is not field replaceable. It is glued into the meter plate. I gently popped it out and then drilled out the hole for the LED. A bit of super glue holds it in place. Reassembly was straightforward, just be careful to re-solder the meter correctly. Here is the meter with white LED goodness:

Photo May 23, 3 49 57 PM

Keep in mind that doing this retrofit likely voids any warranty you may have with MFJ so do it at your own risk and as always, Your Mileage May Vary.