I Need Help To Build A Weird Device

[Ian_Gere]

Some of you may remember that a while ago I bought a set of Soviet tank drivers' night vision gear. Well, getting it all working as a belt supported rig hasn't been entirely simple, principally because the right eyepiece of the first one they sent me failed not long after I got it set up. That was a bummer, since I had just left good feedback for the eBay seller - but they have been great and sent me a whole new set. But also the first time I tried it out, plugged into an 11.1V LiPo, it didn't work at all.

So now the helmet and IR lamp run off a 2200mAh 12V lead acid battery, which conveniently fits into a late Soviet era personal medical kit pouch. At some point I may see if the tubes in the eyepieces work better with the transformer powered by adding a single fat LiPo cell, to make the nominal voltage 15.7V, because the people I bought it from told me they can take up to 18V. But for the time being it works well enough to be usable as is.

The problem is that to my mind the main reason to use NVG is stealth and being a knackered old fat git doesn't help with that mission at all. But then again, there is always passive stealth, or sitting still waiting for the enemy to blunder into my field of fire. And that is where this thread comes in...

...because the transformer makes a very quiet clicking sound. It isn't a sharp sound, nor is it loud enough to be noticed over the rustle of your own clothing and equipment, much less localised by average adult ears. Not true however of young fresh ears, especially those who have not yet discovered the joys of night clubs, and can thus hear a mouse fart at 50 paces.

Now, I do have a solid state high voltage power supply with which I could attempt to replace the transformer. At some point I may well give that a go - but I know nothing about HT and wearing something on my head with 15+KV running through it with bodgetastic components involved does not immediately fill me with enthusiasm.

So what I want to try building is a quiet distraction device - something which makes just enough noise to cover and/or confuse the sound of the transformer. It needs to be small, relatively light, throwable, robust enough to withstand being thrown, and findable in the dark without having to rely just on the sound it makes (because my own ears are about 2/5ths fucked).

What I'm imagining is something like a tennis ball with holes drilled in it, cut mostly into 2 halves and stitched back together with wire. Suspended on elastic inside will be a few IR LED's powered by a small battery and "X" - the noise maker. Something electronic would be great, so it could be powered from the same battery as the IR LED's and turned on/off by poking something like a pen through a drill hole to press a switch. But something mechanical, a wind-up toy part or something, would do the trick - just so long as I could get to the winder with a screwdriver or something, without having to disassemble the thing just to wind it.

So there it is people... any ideas would be gratefully appreciated.

 

[Ian_Gere]

Oh yeah, in case anybody is interested in a similar project, I bought the NVG from tdm_electronics. I can fully recommend their customer service and their prices are very good compared to most places which have this gear for sale regularly.

 

[Russe11]

Recordable greeting card would be my starting place for sound. You can then record whatever sound you want. If you tie it to a tree and activate it by pulling a string, the person approaching will hear your message and investigate. I don't know whether they loop the sound so you can just throw it and leave it running.

How about a cooling fan with a bit of cable tie set to rattle on the blades?

Some sort of sex toy?

 

[n1ckh]

How about a wobbly ball ??

 

[TacMaster]

You could take a leaf out of WarZ and develop a 'Disco Ball' device- in the book these were plastic spheres with LEDs of all colours embedded in it, which would distract zombies in the book. It might be a bit of an effort, but if you wanted to complicate it further you could set up a radio receiver in it which would turn the LEDs on or off when a specific frequency is broadcasted by a radio.

You could also put a small buzzer in the device which would work for the sound element of distraction.

 

[Chock]

Since you are going to be using night vision, I'm presuming it will be dark, so how about this... Get a cheap torch from a pound shop, and rig it up with this cheap toy:

http://www.ebay.com/itm/MAD-LIBS-Word-Game-Keychain-Keyring-ELECTRONIC-Records-Voice-Madlibs-Basic-Fun-/120791193732?pt=Electronic_Battery_Windup_Toys_US&hash=item1c1fb75884

That toy will let you record your voice, or any other sound and then it will randomise what it has recorded and play it back, so you won't get exactly the same decoy noise all the time, which means it won't sound like an obviously repetitive decoy. coupled with a torch going on and off, it will sound and look a lot like a couple of people sneaking about and flicking their light on for a second or so to suss out what they are doing.

The controller and servos from a cheap radio controlled toy will allow you to trigger your device remotely, by rigging the servo movement to the on/off switch of your device.

I've occasionally done something simpler - but similar - to that at Trojan Airsoft on their pitch black CQB 'Purge Night'. I take along a few cheap small LED torches, I usually have these as back up tac lights which can be quickly taped to a gun if your real one goes U/S, but they also make excellent decoys if you place them behind cover so that a bit of light can be seen. Being that the torches were only 1.50, it hardly matters if you lose one or two of them, and you won't care about throwing them either for some decoy noise, so even if they break on impact and the light goes out, they've still made a decoy sound. Sometimes I've lent them out to others on my team who don't have a suitable tac light on a hire gun or whatever. Never travel without a few cheap torches if you are doing night CQB, they have loads of uses as decoys or for lighting up entry/choke points, or simply to help people out if they haven't got a light on their weapon. Make sure you carry some tape too, so you can secure the things to whatever you have to or to tape them to the end of the weapon.

For IR-based NV systems (not sure if yours is that or a LLTV based system), you can of course swap the LED bulbs in torches to IR bulbs with a quick bit of DIY desoldering/soldering, and that will extend the range of your NV if yu place those torches to point at entry points etc.

Remember to play the A-Team music whilst you are making your device, and for an added bit of authenticity, you could try 'welding' with a burning torch lol (always used to make me laugh when they showed them doing that on the A-Team, still, it was only a bit of harmless entertainment, not a documentary).

 

[Chock]

Incidentally, if anyone wants night vision, but doesn't want to spend a fortune on some ex-military gear and having to rig up a power system because they don't have a convenient T-55 Main Battle Tank to plug their NVGs into, you could do a lot worse than to get hold of some of these things:

http://www.ebay.co.uk/itm/Spy-Net-Night-Vision-Binoculars-Goggles-50ft-Range-Childrens-Adults-/400728582224?pt=UK_Photography_Binoculars_Monoculars&hash=item5d4d48e850

Although they are intended as, and indeed marketed as a toy, hence the low price and 'spy' blurb, they do actually work pretty well and are certainly good enough for checking out large rooms in darkened CQB. They have an IR illuminating beam on the front and two built in screens to give stereoscopic vision. Of course for thirty five quid one can hardly expect them to be as robust as an AN/PVS-14, and they are hand held as opposed to a helmet mounted monocular, but they do actually work pretty well for all that. Check out this youtube video of them in action:

Those are actually the older model incidentally, the newer ones look a bit less military-esque, but can record to an SD card and have a few fake thermal effects so you can change the visuals to look a bit like the thermal view of the Predator in the Arnie movie of the same name, which would allow you to throw in all those Arnie-ism classics such as 'Ged to de choppaaar!' and 'Chim Hopper, i know deez man, Green Berets oud ov Ford Breg' as you skulk about in the dark.

If you want a cheap (i.e. about thirty quid) helmet-mounted monocular solution which uses similar IR technology, they also make this thing, which could easily be adapted to fit the helmet rig on a PASGT or FAST helmet:

http://www.amazon.com/Spy-Gear-Ultimate-Night-Vision/dp/B00D6N8V18/ref=sr_1_2?s=toys-and-games&ie=UTF8&qid=1375962052&sr=1-2&keywords=spy+gear

Anyway, I'm off to cover myself in mud so that nobody can't see me with their NV gear, make a bow and arrow out of some old M203 rounds and a bit of wood, then indulge in more Arnie-like Predator quotations...

'We move... five meeder spread... no sound...'

 

[Ian_Gere]

Thanks lads, keep 'em coming! I've got to go out shortly then get some sleep, but as I said, all ideas gratefully appreciated.

 

[Chock]

Here's another thing you can add for a bit of a laugh next time you are doing CQB in the dark. Stick this on your phone to freak everyone out:

https://play.google.com/store/apps/details?id=com.j&hl=en

It looks and sounds exactly like the one in the movie

 

[jcheeseright]

Tennis ball with a clicker inside and an IR v-lite taped/glued to the side so you can find it using your night vision.

I wouldn't recommend anyone tries to use the toy 'night vision' types in any serious way though... the bank of HUGE IR LEDs on the front glow pretty red, provides a nice bright red aiming point for people to shoot at your face!

 

[Chock]

Actually those IR projector lights don't really appear that bright when you see them from more than a few feet away, they do show up on video, but really they are only the same as the bulb on the front of a TV remote, and those things are hardly a laser designator, so yes, they do show up a bit, and I'd agree that quick glances through the thing rather than staring at one point for ages would be the smart thing to do. Personally, I think they are more useful for simply being able to see where you are going; this is particularly true in Trojan's Weir Mill site in Stockport, which on things like their Purge CQB night, is completely blacked out, so it's bloody dangerous navigating the stairwells in total darkness (that place is six storeys high). Week before last, some guy fell down a stairwell and cracked his head in that place. The marshals had to declare a ceasefire whilst they sorted him out. Don't think he was too badly hurt in the end, but more than once in that place I've been walking in pitch black and not known there was a stairwell right in front of me, and even just dropping one step when you're not ready for it can hurt a bit. so I'd take a tiny IR light over flipping my tac light on any day of the week, because putting your tac light on in those stairwells is like wearing a bell as far as stealth is concerned and pretty much guarantees you're gonna get a face full of gas blowback pistol shots when you turn the corner!

 

[jcheeseright]

While ONE of those IR LEDs isn't very bright, a whole bank of them can be seen from a good 30 or 40 yards away pretty easily. I know, I've done it. Once someone's vision has fully night-adapted those little red glowing LEDs are very very obvious.

Not only that, the lenses on those things are (obviously) very cheap and the image you get is not at true 1x magnification, it's often more like 1.2-1.3x, combine that with the fact that the lens (singular!) itself will be offset from your face by several inches makes walking about pretty hazardous in itself, especially given that with only one objective lens, regardless of the amount of screens inside of it you'll have no stereoscopic depth perception.

Trust me, if those spy goggles were useful on any level then people would be using them all the time, I play a LOT of night games and have only ever seen that kind of stuff a handful of times and in all of those cases the person using them has ditched them in favour of a torch in fairly short order. They're a nice idea, but in practice they're £35 worth which with night vision stuff is effectively 35p worth. You're genuinely better off with a keyring LED torch.

 

[Chock]

Oh i agree with you on many points, as I said, they are a bit of fun for 30-odd quid, with some use in specific circumstances, notably the one I mentioned with the stairwells when you are not likely/expecting to be shot at because anyone who could would be around the next flight of stairs, but are concerned with not going flying down the stairs that you literally cannot see at all, but don't want to announce your presence by flicking your tac light on. I know in this circumstance they are useful, because I've got several knife kills on people announcing their presence with a tac light as they creep around doors on stairwells, and with no direct line of sight to you from them, the IR lights are not going to be an issue.

There's no way one could or should expect them to have the same utility as a AN/PVS-14 or some other equally flashy and expensive military kit, nor be as robust. Clearly they are going to be CMOS sensors rather than triple CCD plates and are not going have Schneider Kreuznach lenses in there, but frankly, I've spent thirty quid going up to a bar and buying a round of drinks in some places - cough, cough, Paris - so I think they are a bit of fun for not a great deal of money with the odd occasion where they are of some use.

Like i said, just a bit of inexpensive fun for anyone not prepared, inclined or in a position to afford some expensive NVG kit.

Anyway, back on the topic in hand and to the OP, what is it on the transformer that is creating the clicking noise? Is it a relay in the thing, or a fault, sometimes a minor short can cause clicking in transformers, so I'd check to see if you haven't got any loose connections or dry solder joints. Sometimes clicking can be caused by loose windings or laminations in a transformer, when the loose parts move back and forth as the voltage fluctuates. Apparently that can be solved by supergluing the offending bit to immobilise them, being sure to let the glue dry thoroughly before cranking it up of course.

Failing that, have you considered trying to insulate the sound coming from the transformer? I realise you might not be able to seal it off as it probably has to have some ventilation to dissipate heat, but could you mount it on rubber bushes to prevent it transmitting as much sound to the casing? or put some foam around part of the casing to act as a sound baffle?, or even brace the casing so it cannot vibrate and transmit the sound so well?

 

[PT247]

how about a clockwork alarm clock that ticks loudly?

 

[Chock]

Even better, a clockwork alarm clock with this sellotaped to it, plus a few fake wires and detonators and a battery:

http://www.ebay.com/itm/Fake-Red-Dynamite-TNT-Cartoon-Gag-Toy-Prop-Funny-Joke-Cowboy-Clown-Western-/350850372247?pt=US_Costume_Accessories&hash=item51b04fd297

 

[Ian_Gere]

How about a wobbly ball ??

What is a wobbly ball?

 

[b1n0gHo5t]

Why not put cans on a piece of metal wire and tie them to anything near you
though if its a night game i guess you could end up with team mates stumbling into them

or a motion sense that sets off a Bullshit detector or something similar lol

 

[Ian_Gere]

I read reviews of those kiddy spy goggle thingies a while back and one said you'd be better off turning them the opposite way around and using the screen as a torch because it's so bright inside that it fries your eyes looking at them!

For some reason I just didn't even consider a motor - I believe i have a spare laptop fan lurking somewhere in my cupboards, so i think that will be the plan. I think i was fixated on an electronic solution because i was tired and coming to the end of a dose of pain meds, but yeah, i got what i wanted - some great creative solutions.

I dunno whether the transformer sound is a fault, but it is present in both the units i have and about the same in both. For all i know they could also be making a very high frequency whine, above the range of my semi-destroyed hearing. I will open one of them up at some point to see what a gwaan inside, but i suspect that the transformers are mounted on rubber already - it is a very quiet sound after all and, as i said above, not a sharp sound.

The problem with muffling the sound any more than the steel container the transformer is fitted inside does is that it is head mounted - it's a big ol' rig as it is, already at the edge of what is practical in the field. My immediate plan is to try to find a low cost practical solution, so a distraction device seemed like the way to go. I've used a few different light devices as distractors before, but the problem with all of them is that, as soon as you turn the light on, your position is compromised, no matter where you throw it, even if your position is behind cover, because the arc of throw is immediately seared on the light starved retinas of the opposition - like the predator back tracking a spear...

The main idea then is subtlety - it only needs to make localising the tiny sound the transformer makes difficult and actually, although a more obvious device may be more distracting, it still tells the opposition that something is up. For most people, the sound i'm trying to disguise will not immediately register as "the enemy" anyway and "Device X", if successful, will simply confuse the issue - possibly make those who can hear the transformer doubt their senses... at least as to where the sound is coming from.

 

[Ian_Gere]

BTW, for those who do not know what a PNV-57A looks like, this is it:

​

...minus the ear flaps.​

 

[jcheeseright]

Get that into the stalker thread! How effective are they?