Klarus XT11 (XM-L U2 - 1x18650, 2xCR123A/RCR) Review: RUNTIMES, BEAMSHOTS, VIDEO+

sog_sniper

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Thank you very much Selfbuilt for the prompt response...Another query from a newbie, what is the purpose of using PWM???
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selfbuilt

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Thank you very much Selfbuilt for the prompt response...Another query from a newbie, what is the purpose of using PWM???
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Short-version, it is a simple way to reduce the output of a light, by reducing the amount of time the light is on (i.e., variable amount of time full-power "on", in pulses of a fixed frequency - thus, pulse-width modulated). Due to the phenomenon of persistence of vision, this will be perceived as dimmer light (assuming the frequency is high enough).

The competing method known "current-control" actually involves driving the emitter at lower levels (which is more efficient, as the emitter is more efficient at lower currents). But current-control is difficult to do stably at lower outputs, and will generally result in some tint-shifting of the LED (due to the varying drive levels). Continuously-variable lights are almost always PWM-controlled, and some defined-level levels use PWM as well (especially for low output levels). See the electronics subforum for a greater discussion.
 

sog_sniper

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Short-version, it is a simple way to reduce the output of a light, by reducing the amount of time the light is on (i.e., variable amount of time full-power "on", in pulses of a fixed frequency - thus, pulse-width modulated). Due to the phenomenon of persistence of vision, this will be perceived as dimmer light (assuming the frequency is high enough).

The competing method known "current-control" actually involves driving the emitter at lower levels (which is more efficient, as the emitter is more efficient at lower currents). But current-control is difficult to do stably at lower outputs, and will generally result in some tint-shifting of the LED (due to the varying drive levels). Continuously-variable lights are almost always PWM-controlled, and some defined-level levels use PWM as well (especially for low output levels). See the electronics subforum for a greater discussion.

Well said Selfbuilt, thank you very much for the explanation... Two thumbs up for you and please continue sharing your comprehensive flashlight reviews..... More power
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silverspurr

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[SIZE=+1]I recently purchased/received the Klarus XT11.
I have owned the XT10 for over a year and decided to upgrade to the XT11.
While the color and brightness [SIZE=+1]are[/SIZE] very nice, there are two flaws this light has that for me make it uncomfortable and unpredictable when having to use the light.
#1. as I'm sure you have heard from others, the anti-roll plastic ring not only is not a tight fit (the XT10 is a perfect tight fit), it spins freely in a circle AND up and down AND if you put your index finger on one side and your thumb on the other side of it, it wobbles side to side which for me is terrible especially at $71.00 - $89.00.
However the wost design flaw is the fact that the strobe is set off too easily when I don't want it to go off.... simply by using the larger button/switch.... if my thumb even slightly touches the smaller mode button/switch.... the strobe goes off! Terrible.
This is absolutely not an issue with my XT10.
I don't want to (should not have to) have to consciously face the smaller mode button/switch outward each and every time I want to/need to use momentary on... without having the strobe fire off!
[SIZE=+1]The Klarus XT11 w[/SIZE]ould be a superb light (as is the XT10) if not for these two (2) design flaws.

The problem with the newer XT11's strobe/mode button is it's extremely "hair-trigger"[SIZE=+1] which[SIZE=+1] is why [SIZE=+1]the strobe fires when I don't want it to, simply when I press the main (round) button.. but if the slightes[SIZE=+1]t pressure/touch of my thumb makes even the [SIZE=+1]slightest[/SIZE] contact with the smaller (half moon) button, the strobe fires.
By comparing both the XT10 [SIZE=+1]and XT11 one in my left hand the other in my right hand, [SIZE=+1]there is a clearly audible and tactile sound/feel when the XT[SIZE=+1]10's strobe button is depressed with my thumb, and on the [SIZE=+1]XT11.... [SIZE=+1]I barely hear or feel any click[SIZE=+1], it just fires[SIZE=+1].[/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE][/SIZE]


[/SIZE]
 
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selfbuilt

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However the wost design flaw is the fact that the strobe is set off too easily when I don't want it to go off.... simply by using the larger button/switch.... if my thumb even slightly touches the smaller mode button/switch.... the strobe goes off! Terrible.
This is absolutely not an issue with my XT10.
The XT10 and XT11 actually use the same tailcap and switch. It sounds like your XT11 sample is a lot more sensitive than your earlier XT10. I don't know if this a general change over time, or simply natural variation in sensitivity levels among all the switches. But it means that you would swap the tailcap from your XT10 on to your XT11, to keep the sensitivity you are used to.
 

TEEJ

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This looks handsome, indeed...

0fb073045afcac1759df92f64544c042.jpg


Image taken from Klarus' website.

OW!

I think that version would not be good to keep in my front pocket...I think it would put a hole in my pocket, and some stuff very near to that pocket...like ME.

:eeksign::eeksign::eeksign:
 

silverspurr

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The XT10 and XT11 actually use the same tailcap and switch. It sounds like your XT11 sample is a lot more sensitive than your earlier XT10. I don't know if this a general change over time, or simply natural variation in sensitivity levels among all the switches. But it means that you would swap the tailcap from your XT10 on to your XT11, to keep the sensitivity you are used to.

Great suggestion, thank you very much.
Unfortunately I just tried as you suggested removing the tailcap and switch from the XT10.... I was able to remove the initial aluminum threaded ring... however once I got down to the switch, I have no idea how I can/how to remove it as there are not two 'notches' to put a tool into it and un-screw it as is on the first aluminum ring.
I can't take a chance and force anything as someone wants to buy XT10 from me and I don't want to break anything by accident.
I wish I could change them as you suggested, that would probably solve the issue... I'm just not very tech/mechanical savvy when it comes to taking these apart.
 

TEEJ

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Great suggestion, thank you very much.
Unfortunately I just tried as you suggested removing the tailcap and switch from the XT10.... I was able to remove the initial aluminum threaded ring... however once I got down to the switch, I have no idea how I can/how to remove it as there are not two 'notches' to put a tool into it and un-screw it as is on the first aluminum ring.
I can't take a chance and force anything as someone wants to buy XT10 from me and I don't want to break anything by accident.
I wish I could change them as you suggested, that would probably solve the issue... I'm just not very tech/mechanical savvy when it comes to taking these apart.


LOL - you don't have to take it apart...I think you just swap them.

:D
 

selfbuilt

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LOL - you don't have to take it apart...I think you just swap them.
Yes, that's what I meant - you just exchange the whole tailcap between the two lights. The only potential issue is that you might have a slight mismatch in the anodizing colours.

I wouldn't recommend disassembling the XT10/11 switch itself, as it is a little more complicated than most (due to the dual switch design).
 

silverspurr

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Yes, that's what I meant - you just exchange the whole tailcap between the two lights. The only potential issue is that you might have a slight mismatch in the anodizing colours.

I wouldn't recommend disassembling the XT10/11 switch itself, as it is a little more complicated than most (due to the dual switch design).

As you suggested, I just now simply exchanged the tail caps (XT10 to the XT11) .... PERFECT!! Problem solved!!
'TEEJ'.... boy do I feel like a dope, trying to exchange the actual 'switches' LoL!!
Lucky that the two are the exact same anodized color!
There was a # (X05542) printed on the XT10 cap while no # on the XT11 cap, but absolutely no big deal.
'selfbuilt', thanks a million for your help, very much appreciated.
Works perfectly now... no strobe firing off accidentally due to the highly sensitive smaller mode button/switch which came on the XT11.
Great light, nice white LED light color.
I purchased the optional more 'aggressive' strike bezel which is kind of fun.. LoL.
Now if only they would design the XT11 so the plastic anti-roll ring wouldn't be oddly "very loose" and spin around like a pin wheel.
But at least the other issue is now gone/fixed!

Thanks again!
 

selfbuilt

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Works perfectly now... no strobe firing off accidentally due to the highly sensitive smaller mode button/switch which came on the XT11.
Good, glad it worked out for you.

I've just gone back and handled my XT10, XT11 and XT30 (all use the same inter-changeable tailcap). While none of mine are as sensistive as you describe, the older XT10 does seem to require the firmest push to activate strobe (with the newest XT30 being the most sensitive). Could be a gradual change in sensitivity over time, but might also be completely random - don't have enough samples to say.

Cheers!
 

TEEJ

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As you suggested, I just now simply exchanged the tail caps (XT10 to the XT11) .... PERFECT!! Problem solved!!
'TEEJ'.... boy do I feel like a dope, trying to exchange the actual 'switches' LoL!!
Lucky that the two are the exact same anodized color!
There was a # (X05542) printed on the XT10 cap while no # on the XT11 cap, but absolutely no big deal.
'selfbuilt', thanks a million for your help, very much appreciated.
Works perfectly now... no strobe firing off accidentally due to the highly sensitive smaller mode button/switch which came on the XT11.
Great light, nice white LED light color.
I purchased the optional more 'aggressive' strike bezel which is kind of fun.. LoL.
Now if only they would design the XT11 so the plastic anti-roll ring wouldn't be oddly "very loose" and spin around like a pin wheel.
But at least the other issue is now gone/fixed!

Thanks again!

LOL

Glad it worked out.

I tend to install GITD O-rings on my lights to make them easier to find in the dark/if dropped, etc...Not replacing the lights OEM functional O-rings....just adding more around the head and bodies, etc.

I found that if I installed a ring where the ring was, it kept it from spinning too, doing double duty.


BTW - the tail cap and ring for the XT20 are a direct swap as well. I can even use the tail cap from a ZL SC600 on the back of the XT11, its a perfect match (Turns it into a twisty UI though, as the SC600 has no switch in the cap...)

:D
 
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tadbik

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It's interesting to read about the problems with the removable grip ring. My XT11 came today and it has a metal ring.
 
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Putty

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Jan 28, 2013
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I just ordered one of these off of Amazon today. I plan to attach to my shotgun. Seems like a very bight light.

Thanks for the review.
 

eh123456

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Aug 13, 2011
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Send Klarus an email, they will send you a metal one (via your retailer).
I did and they told me to go back to my retailer to collect a metal one, very good after sales service :)


Mine is plastic.... and I got it last month from Going Gear.
 

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