Looking to build a 940nm IR light for hunting. I currently use a stock sight mark illumintor paired with a Wraith 2-16 optic.
Ive done some digging around here and seen some options for the Weltool LH2 head and some builds that were around the convoy C8. The Weltool seems like a decent option, but I havent been able to find a pressure switch for it. The fact that its not potted also gives me pause. Another option Ive been looking at is the Nitecore Ci7, but thats a back up option.
What Im looking for:
Regulated, constast output
~ 2a to 2.5a draw tops.
Beam pattern similar to Weltool LH2.
Can use a pressure pad (momentary option is a bonus)
Single cell body (21700 compatible is ideal)
Single mode
Can survive .350 Legend recoil.
The why is personal preference. Most nights we use monoculars to spot and bring rifles on after we’ve spotted eye shine or glow on thermal. I want something that holds light output and lets me clear up my sight picture out to 200 + yds (last night’s long tract was ~140 yds by comparison). The sightmark IR loses output as it goes and I start losing image clarity past 50 to 75 yards.
I dont mind building around an LH2 head, if I can find a good body and pressure switch for it. I want to keep the total build under $200 US, so paring with a sure fire pressure pad isnt an option at the moment. Im down to try a convoy build, Im just concered about it survivng my use.
Any suggestions or tips would be appreciated to help narrow down some good options.
Im open to most options that work, from a good aspheric p60 drop in to swapping emitters into an existing platform.
You could try going with a Convoy M1 (or M21B) and an Osram SFH4724 emitter, you would need to electrically insulate the MCPCB that the LED sits on, as well as using a low current 3v driver (1A max). It is the same LED used in the weltool LH2.
Convoy also has a remote switch available for it, you can replace the remote with a pressure pad using some heatshrink.
There are some knockoff surefire-clone pressure pads available on aliexpress that you can hack up without shame (for the convoy build, I don’t trust the plugs), or you could use a Modbutton on the LH2 (using a W35 or W65 body tube and remote-capable tailcap).
I’ll probably end up doing that as well. I ordered a Convoy C8 with an SST10 940nm iirc. I also saw in another post that somebody was going to try a klarus pressure pad, so I threw one of those in too.
I like the M21 and will most likely do a build with that as well.
I did have another thought in the meantime. Are there any optics for a convoy C2 that would allow me to run a pencil beam or something real focused with an aspheric lense? I dont need any spill. Not sure if it exists, but the compact size would be nice.
If I can run one small enough, I wouldnt mind exploring other additions. But it would have to be the same deal with need a pressure pad.
Question on the driver, would I get good output on 1a? Thats only a 3 to 4w output from the emitter. Also, would it benefit me to have a soft start driver?
Also, one more question, could you guide me on electrically isolating the driver? I plan to put potting compund in these, would that do it?
I found that the Weltool LH2 is 860nm, using the SFH4715 instead of the 940nm SFH4725, not sure exactly which generation. I built a C8+ with a 940nm and it is not as visible by a huge amount, so I recommend going 860nm (if using the Osram SFH4715) or 850nm if using the SST10.
If you’re still open to building something, use the 17mm 1.5A buck-boost convoy driver (single mode, 3v output) and a SFH4715 LED, you can buy it installed on a 20mm PCB on aliexpress. A Convoy C8+ is a good host but it will have spill, I don’t know of any suitable TIR or aspheric options for it but you can always ask Simon (convoy store owner)
You don’t need to isolate the driver, what you want to isolate is the MCPCB if you are using the Osram LED, but that csn be easily fixed by using an aluminum MCPCB (where the LED is soldered to). Another option is to put kapton tape on the bottom and paint the edges with something non-conductive, like nail polish so that it doesn’t short out. Make sure to use a non-conductive thermal paste, I like Arctic MX4.
Understood. I will be doing a build as well to fine tune what I want. I dont mind the spill, that was primarily for a C2 throw build if it was possible, but thats a side goal.
I’m trying to avoid an 850/860 build. The guys I run with used to use IR and had some issues after a while. Part of what we target is hogs to prevent crop damage. They said hogs started wising up to seeing the red glow on the IR lights they used. Seems a stretch, but who knows. This is their gig and their hunts. Theyre pretty damn good at it too.
I’m hoping the instensity of a highly focused light will help offset the light loss of the 940nm. I have a fairly narrow FOV anyways, so any light outside of that is wasted. We’ll find out one way or the other.
940nm still glows red, slightly less then 850 but not enough to matter. AFAIK the glow is a byproduct of running the LEDs so hard, the same way visible LEDs tend to get slightly cooler with more current. The best bet for hunting is to use a good filter, or thermal (needs no light).
I’ll eventually make the switch to thermal. I wanted to start off with IR to keep costs down. Also didnt realize 940nm would still glow… we’ll see how the C8 looks when it comes in and gets mounted.