Category: Oddities

Once is happenstance, twice is coincidence:

Three times is enemy action, but we’re not there yet. I was willing to believe something I’d done had killed both of the radios, even though it seemed unlikely for them to last five years and fail almost simultaneously.

So I dismantled this one to see what’s inside. Pull off both knobs, remove the two screws at the bottom of the battery compartment, pry gently with a small screwdriver, and the whole PCB pulls out:

A bit more prying separates the big pieces:

Looking closely at the main PCB showed some problems I definitely didn’t cause:

Although it’s been riding around on my bike, the white blotches on the PCB came from inadequate flux removal after hand soldering.

A collection of images taken through the microscope reveals the problems:

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I swabbed off the crud with denatured alcohol to no avail. The bottom side of the PCB has even more components and, I’m sure, even more crud, but I didn’t bother removing all the screws required to expose it, nor did I dismantle the other failed HT.

I doubt Wouxun’s QC improved over the last few years, which means the two replacement KG-UV3D radios I just bought are already on their last legs, despite my paying top dollar to the same reputable source that sold me the first pair.

We’ll be ready for new radios on new bikes by the time these fail.

A high energy collision / accident / mishap in front of Adams Fairacre Farms (a.k.a., the grocery store) demolished 20 feet of their dry laid stone wall along Rt 44, flattened several bushes, gouged trenches in the grass, and scattered plastic debris into the parking lot. The remains of a headlight eyebrow running light emerged from a snow pile:

From the back:

Contrary to what I expected, it has one white LED at each end of the chromed reflecting channel, topped with a shaped plastic lens collecting the light:

The LED PCBs are in series, which produced a backwards wire color code on one end:

The other end looked more reasonable:

The white SMD LEDs draw 300+ mA at 3.6 V, so they’re obviously depending on external current limiting provided by the regulator PCB, sporting a TLE4242 linear current regulator and a handful of passives:

AFAICT, they didn’t use the chip’s PWM control input or its LED failure status output.

Extracting the various PCBs from the wreckage and reconnecting the wires produced a satisfactory result:

The regulator limits the LED current to 120 mA at any input from a bit over 7 V to well past 12 V, with each LED dropping 3.0 V.

Dunno what I’ll use this junk for, but at least I know a bit more about eyebrow lights. The chip date codes suggest 2010 and 2012; perhaps linear regulators have become passe by now.