TK75 2,900lm SOOO LATE TO THE PARTY ON THIS ONE.

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
Hi and Seasons Greetings,
I was using my old, but amazingly reliable and unmodified TK75 last night, and noticed a small quirk with the ui ( maybe there has already been a thread on this point ). When switched on, the lowest mode emits x cd ( I have not measured the actual output ) of light. With the light still switched on, and a cycle through the four brightness levels, the low output appears to be roughly 2x cd ( double the brightness to my naked eye ). Subsequent cycles of the output levels, still with the light not having been switched off then back on, give the same result. When the light is switched off, then back on, low goes back to that real low output initially, then up to the higher low ( !?** ) for the duration of that power up, after a cycle through the four outputs. I did this about ten times, and every time, the result was identical. I tried swapping out cells, same result. Cleaning of anything that can be cleaned, same result. This is not an issue that I am worried about, as it appears very consistant and has probably been doing it since day one. Just that I have never noticed it prior to last night. Its not even something I would alter, if I could. Has anyone else ever experienced this behaviour with their 2.9klm TK75, and was it a 'known' quirk of this model TK??
Cheers and a Happy and Safe Xmas to you.
 

aginthelaw

Flashlight Enthusiast
Joined
Jan 28, 2007
Messages
2,655
Location
NJ, USA
Mine doesn't do it but I haven't found the box or paperwork yet to know if I have the 2600 or 2900
 

NoNotAgain

Flashlight Enthusiast
Joined
Jan 25, 2014
Messages
2,364
Location
Blue Ridge Mountains, VA
I've looked at my TK75 2600, 2900 and Vinh modified TK75KT lights. All operate from the lowest setting and cycle through, and return to the lowest.

If memory serves me, the TK75, 2600 lumen light used the Cree XM-L emitter. The pcb is white in color which easily seen around the emitter.
The TK75 2900 lumen version uses the Cree XM-L2 emitter and the pcb is green.
 

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
I've looked at my TK75 2600, 2900 and Vinh modified TK75KT lights. All operate from the lowest setting and cycle through, and return to the lowest.

If memory serves me, the TK75, 2600 lumen light used the Cree XM-L emitter. The pcb is white in color which easily seen around the emitter.
The TK75 2900 lumen version uses the Cree XM-L2 emitter and the pcb is green.


Its a weird one, its like about a 5 lumen low at switch on, then with a cycle through the four outputs, the low is ' normal ' and remains so regardless of how many cycles of the output occurs. Not until the power is cycled off then on again, does this real ' low ' low appear again. Its probably been happening since i've had the light, but has taken me some four years to notice............hmmmm.
 

blah9

Flashlight Enthusiast
Joined
Mar 10, 2011
Messages
2,105
I never noticed this before, but my modded TK75vnkt does this too. I believe it's the 2900 lumen version originally.

I've also noticed a few times that the LEDs will stay on very slightly once in a while after I turn the light off, but that's a separate issue. I'm not too concerned about it though because I only use that light for certain purposes so it's not a big issue. Maybe I should think about emailing Vinh about that sometime though. I'll have to see if that still happens.

To clarify, I mean that they barely glow. Has to be super dark to even notice it.
 

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
I never noticed this before, but my modded TK75vnkt does this too. I believe it's the 2900 lumen version originally.

I've also noticed a few times that the LEDs will stay on very slightly once in a while after I turn the light off, but that's a separate issue. I'm not too concerned about it though because I only use that light for certain purposes so it's not a big issue. Maybe I should think about emailing Vinh about that sometime though. I'll have to see if that still happens.

To clarify, I mean that they barely glow. Has to be super dark to even notice it.


Yeah, i dunno what the go is with it, and it certainly doesnt concern me greatly. Its just unusual behaviour, that is not mentioned in any literature re the light. The good thing is its extremely consistant in the way it happens, and doesnt otherwise affect the way this exceedingly reliable and handy torch ( whoops, flashlight ) operates. Its something that wouldnt put me off buying one, if they were still available new.

:thumbsup:
 

aginthelaw

Flashlight Enthusiast
Joined
Jan 28, 2007
Messages
2,655
Location
NJ, USA
Sorry it took me forever but yes I do have the 2900 Lumen model. And try as I might it never comes on in super low like yours. You're just using the power button to turn it on and it goes into super low mode? You're not pressing & holding the button to turn on?
 

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
Sorry it took me forever but yes I do have the 2900 Lumen model. And try as I might it never comes on in super low like yours. You're just using the power button to turn it on and it goes into super low mode? You're not pressing & holding the button to turn on?


No, its just a normal flick of the button for low low, then anything subsequent to that, and its the four normal modes, until the next power off/on cycle. Its mode memory and flashy ones are normal also.
 

harro

Enlightened
Joined
Dec 5, 2009
Messages
890
Location
Northern Victoria, Australia
Subsequent to what's already been said, I have had the chance to put this torch in front of a professional light meter. The testing was in no way scientific, but close enough to reveal some interesting figures. From the front of the lens on the TK, to the peak of the sensor dome, the distance was 1 Meter. The max was then obtained by 'fishing' with the sensor. The cells were Eagletac 3100's fully charged, then run on high in the torch for about two minutes. Then the measurements were taken.

Turbo 98,400 lux ( Just for the sake of it, and close to the manufacturers claim ).

Normal low 973 lux ( after a couple of cycles through the four outputs ).

Power on low 284 lux ( at power up on low with no cycle through modes ).

The two low figures sort of sit with the ' three times the lux for an apparent double the brightness to the human eye '. This 'test' was repeated a couple of times, with very similar figures and no real changing of the 'power on low'. At least its consistant ( maybe a hidden moonlight...... ).
 
Last edited:

blah9

Flashlight Enthusiast
Joined
Mar 10, 2011
Messages
2,105
Yes, definitely doesn't surprise me with what mine looks like as well. Interesting numbers.
 

CelticCross74

Flashlight Enthusiast
Joined
Aug 30, 2014
Messages
4,021
Location
Fairfax Va
OP for awhile Fenix battery carriages had what has long since found to be just badly designed. I am sure you are aware but for the sake of anyone else that reads this the Fenix battery carriages used is for perfect example the first 2 generations of TK75 and the now defunct TK51 are not well made and kind of slowly lose their ability to conduct electricity.

I still have my TK75 XML2. Luckily the battery carriages in mine are for some unknown reason still perfect. My friends fell apart and short circuited. Strange. Those MASSIVE jumps in output you are having is most likely the battery carriages and possibly old cells. 3400mah Protected cells are what I have in my own TK75.

The eeriest thing about my own TK75? I took a gamble on Soshine 3400mah 18650's as it at the time had PERFECT protection circuits. Those 3400mah Soshines in my TK75 are FOUR YEARS OLD!! I cannot explain it at ALL! NONE of the cells have even begun to lose capacity. It makes NO sense at all!

Fenix DID correct the battery carriage design though you can get them from CPF's Fenix dealer no problem.
 
Top