Maybe he should stick a chocolate bar in his pocket
Some suggestions-
- Beef up all GND and other solder points with MINIMUM 4% silver bearing solder
- AR lens. Look at the issues they had with that Bluetooth programmable ZY-T08 (whatever it was called), they had to switch to a thin plain glass lens to allow the BT signal to pas, AR does a good job blocking RF/EMI
- line the inside of the tail cap boot with foil, even better silver or even lead foil.
- do not dedome, use some intact emitters.
If all those fail
- get some of that Al foil duct tape (the kind for HVAC) and tape the joints in the body
flashlight bodies are pretty much faraday cages anyway, these few changed should make the lights completely EMI proof, I honestly believe this should fix you up, no reason to give up modes/runtime converting to DD
I know there are stuff like mobile phone jammer to block cellphone in some places (opera?). Now we can come out with the “flashlight jammer” to prohibit people from using their flashlight for whatever reason it is. :bigsmile:
Dimbo The Blinky sounds like the voice of experience here. I don’t personally work in a DC, but a friend who works in a large DC regularly uses his Solarforce w/ Nanjg 105c dropin - no problems.
1. Taiwanese ghosts observers/recognition team members reported that only SureFire flashlights would function properly after reaching the suspected site, budget units from Mainland China shuts down automatically.
2. Anyone comes across likely UFO encounters would find electrical/electronic home appliances (HiFi, ovens, TVs, & computers etc) fail shortly.
3.My brother, a retired police officer, found his pre-LED incandescent torch shuts down when climbing inside ancient tombs populated around rural areas in Hong Kong. Strange was the torch functioned flawlessly when he was out the tomb.
The first was one of these 118mm x 23.5mm “Jaws Light” flashlights:
about the time of these threads, which was so underwhelming I barely got one battery through it then left it in a drawer for almost a year.
The 3C (or 3D?) XM-L and 2.8A Nanjg-105c upgrade made it very interesting; so, unable to find another, I bought this one:
to build from scratch, at 115mm x 23.5mm. The threads are different, of course, so no “Lego”; and I like the second one better since it’s available, shorter and doesn’t have a friggin FISH silk-screened on it.
And as you can tell, they’re not truly “clones”, but merely the same roll-of-coins form factor as the S2, “and that’s close enough to perfect for me”… They’re closer to the S5, TBH, but I don’t see enough difference in the whole lot to be worth arguing over.
They both still had the ugly Cree color rings. Since the only “budget” TIRs I could find were 21mm, and this guy:
http://www.ebay.com/itm/5PCS-x-60-Degree-21mm-Reflector-Collimator-LED-Lens-For-Cree-XML-XM-L-LED-/221175825976?pt=LH_DefaultDomain_0&hash=item337f1b4638
listed them at 0.99, I popped on a set & installed them.
It’s not for “throw”, as I could throw one farther than it can throw light, but the beam is broad, all-white and awesome!! The 2.8A mode gets them quite hot, and that right soon, but they’re easy enough to step down to Medium, which is still quite bright.
Hope This Helps…
Dim
If I may be pardoned for one last nearly-OT ramble…
A friend of mine was a radio-dispatched HVAC repairman (no, he was not named Buttle nor Tuttle), & we “upgraded” his van radio… I think the statute of limitations has expired so I don’t have to worry about “Uncle Charlie” coming after me…
We tweaked him up to the point his rig would heterodyne the TV in the house! When he’d pull into the driveway for a visit, he wouldn’t ring the bell, he’d key up & holler “I’m here!”
Okay, that’s OT, but here’s where we get back on track:
We zip-stripped a fluorescent tube to his ladder rack and whenever he keyed up, the tube would light up & flicker to his modulation! THAT was awesome to see going down the road!
You could do that. Take a bare fluorescent tube into your transmitter room or put one (or six) on your tower somewhere for some real laughs. It’s not like you’re stealing power or anything, so you won’t hurt your coverage. You’re just using a natural side effect for … uh … keeping bats safe at night!! Yeah, that’s it. Bat safety!
At least it’s light-related, if inexcusably OT…
Thanks for the reminiscence…
Dim
Ans don’t forget the tin foil in your hat. Oh, and your underwear.
Wow, lots of responses, this forum never ceases to amaze me! Thanks all! Now that I posted that, and got all these helpful responses, I don’t see any DC visits coming up in the near-term. 
Another random thought: it might not be EMF/EMI, but possibly the noise? The DCs I work in are fairly loud, with all the air-conditioning and servers cranking away. Having a conversation with someone right next to me requires raising my voice quite a bit, borderline shouting.
So if indeed I have some poor solder joints in my lights, the noise-induced vibration might just be enough to trigger the symptoms I’m seeing.
These lights do work fine once they’ve been taken out of the DC. And even in the DC, it’s hit-or-miss: I do get some utility out of my lights, just not the pain-free experience I’d like.
I’ve never taken the time to really see what triggers the issues, though. Usually I’m in a hurry to leave the DC as quickly as possible, so I’m focused on just getting the work done.
In the past, before I had a collection of budget 18650 lights, I just used my smartphone with a “flashlight” app which basically just turns the screen white and cranks the brightness all the way up. Some apps also allow use of the built-in camera flash LED. I haven’t used that scheme in a while, but it always worked well enough. And a cellphone is way more complicated than a flashlight (though there are a lot of similarities: LED lights, microcontrollers, lithium-ion batteries, etc).
I think I’ll start even simpler, and next time I’m there, bring even more flashlights and see if they all have problems or any are exempt from it.
Thanks again everyone!
Armadillo hats work well for blocking, (I wear 'em all the time
), but they don’t work too well for underwear! 
I suggest a flashlight HDS are not cheap but they have their Faraday cage “native” in the flashlight
We used to keep track of what the IBM 1620 was doing by listening to an AM transistor radio.
If the EM radiation there is strong enough to shake, rattle & roll the electronics on a driver that is “shielded” inside an aluminum flashlight body, i would be more concerned about the long-term exposure to it over time on your DNA.
Most of it is now DNB…
if he is there long enough it may become DN (OH)
Yes, always a good start to any problem.
Should be on the front page of BLF
Aluminum foil makes a good Faraday cage, at least for testing. You might put aluminum window screen across the front, but I tend to think it will work without that. I don’t see how a direct drive light could have problems with electromagnetic interference.
Unless its the LED its self, I wonder what would happen if you dedomed and removed the ESD diode (the tiny third wire on the top of the board not touching tie die, I rip them off LED’s I dedome sometimes [on purpose] so I dont have to pick silicone from around them to no ill effects)