Streamlight Argo HP

This was my first of two models of headlights. It's a nice light, except for a few flaws, flaws that are glaring enough to make me reticent to use it.

The Argo HP uses 2xCR123A, held horizontally in a row in a tube (with the white inscription in the above picture) below the LA. It's all hunky-dory, except for one thing - that battery tube is a devil to use.

Personally, I need that strap wrench to open the endcap. Otherwise, it's too small and inaccessible (blocked by the strap attachment points) for me to open bare-handed. A buddy of mine managed to do so, however, so YMMV. The cap does need to be fully tightened to securely complete the circuit, and any less will provide intermittent light and no accidental activation protection. This light is the only one that has turned on accidentally, activating itself on two occasions when put into a bag with other lights. This neccessitated a battery change while making camp at night, which is when the aforementioned buddy opened the light for me so I could change out the spent cells. (Always have spares during night activities.)

The inductor hum on this light on low mode is infuriatingly loud.

The beam is wide and splotchy, but pretty white and quite usable. The reflector is actually half-stippled and half-smooth, and I think a full, heavy stipple would improve the beam.

It pulls 0.08A on low and 0.28A on high at 5.2V, for 0.416W and 1.456W of power consumption, respectively.

This headlight is reasonable, but there are better lights for the price and lots of easier battery changes.

Update: This is one of my favorite headlights with a 17670 and a Seoul P4. I do need pliers to twist open the cap, and the 17670 is snug enough that I take off the other endcap and push the cell through with a jeweler's screwdriver, but it works very nicely. Unfortunately, though, I recently discovered that it uses PWM for low mode, causing a sometimes-noticable flicker at 1500Hz. Overall, it's a useful light.