DFA75 laser problem

Flashlights, IR illuminators. Projects, reviews and queries. DIY 'stickies' here too.
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bavarianbrit
Posts: 25
Joined: 16 Jul 2013, 10:42

DFA75 laser problem

Post by bavarianbrit » 08 Apr 2018, 17:04

Hi, I have just bought a used DFA75 (used it once and then never used again? claimed the seller) and the laser seems not to work. Is this a known problem or how can I test the laser?

B&W FOX
Posts: 75
Joined: 24 Feb 2013, 15:28
Location: BUCKS

Re: DFA75 laser problem

Post by B&W FOX » 08 Apr 2018, 17:42

Do you mean a DFA75 front mounted nv unit?
They don't use lasers they come with an IR unit that screws to the side of the body, and operates when the unit is powered up and then when you select the IR function in the menu.
The included IR has a filter fitted to it and makes the unit nearly unusable anyway :clap:
Most owners attach an after market IR to the picatinny rail such as a night master 800 or one of Clive Wards Black Sun Ruby IR units as its the only way to get a good picture..

bavarianbrit
Posts: 25
Joined: 16 Jul 2013, 10:42

Re: DFA75 laser problem

Post by bavarianbrit » 09 Apr 2018, 09:39

In the owners manual it states that a class 1 laser is fitted so I assumed that that was the IR illuminator.
I did try a T20 and the view was much better.

B&W FOX
Posts: 75
Joined: 24 Feb 2013, 15:28
Location: BUCKS

Re: DFA75 laser problem

Post by B&W FOX » 09 Apr 2018, 11:00

You will need more than a T20.IR to get maximum range and ID
The best scope I've found for the unit is a Walther 3-9x56

bavarianbrit
Posts: 25
Joined: 16 Jul 2013, 10:42

Re: DFA75 laser problem

Post by bavarianbrit » 09 Apr 2018, 14:44

I tried the IR switch and was getting 3.7 volts.
I am getting the newer aluminium adaptor this week, the plastic one broke at the rather obvious weak point the first time I put it onto a 56er. As a design engineer it surprised me that it got into production (if it was a car part that broke so easily there would be a total recall to replace all the sold units with the improved version).

B&W FOX
Posts: 75
Joined: 24 Feb 2013, 15:28
Location: BUCKS

Re: DFA75 laser problem

Post by B&W FOX » 09 Apr 2018, 21:31

You may find the following link helpful.

https://www.thestalkingdirectory.co.uk/ ... Byron-Pace

bavarianbrit
Posts: 25
Joined: 16 Jul 2013, 10:42

Re: DFA75 laser problem

Post by bavarianbrit » 17 Apr 2018, 07:31

I have just opened up the laser unit and there is a longish pair of wires going up from the connection area to the laser assembly behind the lens.
Would it be possible to rework the unit to take a 915nm led to replace the non working laser as I am getting a 3.7 volt output from the dfa75 IR switch.
Thanks

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