Range Report PVM-21 Failure to Register Shots

[Starbuck]

My PVM-21 won't register shots. Any troubleshooting ideas would be appreciated.

I have:

Charged the battery
Input bullet weight and appropriate gain setting (123 gn., 6.5mm, 80% gain, FWIW)
Placed lightscreen 10' from muzzle, 3' off ground
Snugged all cable connections
Called Ed Dillon at Neconos who advised me to replace the long cable, which I did

It registers shots indoors, when I shoot my .177 cal air pistol through it, but when I take it out to the range it has registered shots intermittantly at best over the two or three years I have owned it (with many different calibers), and yesterday not at all - it just wouldn't register - the readout just always said "IR DONE".

Have I missed something that I should be doing with the PVM-21? I have searched manual, the Hide and the Net and I see no description or reports of the problem I am having

 

[Lowlight]

Mine is picky as hell, I had to make lines on the unit making sure I shoot directly across straight. Any angle it doesn't work. if you are sure the wires are right, maybe a IR unit is not working.

But the unit is a heck of a lot more work then it is worth. It doesn't talk to the computer correctly, etc, etc... I was let down by it.

Magnetospeed.... just saying.

 

[Starbuck]

Mine is picky as hell, I had to make lines on the unit making sure I shoot directly across straight. Any angle it doesn't work. if you are sure the wires are right, maybe a IR unit is not working.

But the unit is a heck of a lot more work then it is worth. It doesn't talk to the computer correctly, etc, etc... I was let down by it.

Magnetospeed.... just saying.

Thanks LL.I'll review the angles aspect. I've got the Magnetospeed too and love it, but am bothered by the POI shift it causes. Maybe I should learn to get over that....

 

[K2Ballistics]

Mine is very picky as well. Angle is critical as LL pointed out.

I usually find that it performs much better when I place it at least 18 to 20' from the muzzle. Also make sure you are not shooting completely over it. Sounds silly, but is easy to do. Your bullet is still rising at this range. For a scope height of 2", I usually shoot about 2.5" off the bottom of the sensor area...but definitely below the top of the sensor area.

Marked mine with lines as well. Horizontal grad lines on front face to get height right and vertical center lines on front faces of BOTH yellow brackets to get alignment correct. Before you fire, your vertical reticle should be aligned with the center lines on each bracket.


Do you ever get "high bias" errors when starting up the unit? If so, your sensors and IR led's could be out of alignment. Snug your bolts and check alignment with a straight edge across the faces of the sensors and IR's. You should have no perceptible gaps between the black plastic of the sensor/IR housings and your straight edge. If you do, they are out of alignment.

FYI, after some use, I discovered that mine registers "high". This was corrected somewhat by changing my spacing out to 28", but this was no small endeavor.

 

[Starbuck]

Mine is very picky as well. Angle is critical as LL pointed out.

I usually find that it performs much better when I place it at least 18 to 20' from the muzzle. Also make sure you are not shooting completely over it. Sounds silly, but is easy to do. Your bullet is still rising at this range. For a scope height of 2", I usually shoot about 2.5" off the bottom of the sensor area...but definitely below the top of the sensor area.

Marked mine with lines as well. Horizontal grad lines on front face to get height right and vertical center lines on front faces of BOTH yellow brackets to get alignment correct. Before you fire, your vertical reticle should be aligned with the center lines on each bracket.


Do you ever get "high bias" errors when starting up the unit? If so, your sensors and IR led's could be out of alignment. Snug your bolts and check alignment with a straight edge across the faces of the sensors and IR's. You should have no perceptible gaps between the black plastic of the sensor/IR housings and your straight edge. If you do, they are out of alignment.

FYI, after some use, I discovered that mine registers "high". This was corrected somewhat by changing my spacing out to 28", but this was no small endeavor.

Thanks for the suggestions. With respect to moving lightscreen further away from the muzzle, this was how the two PVM-21s were set up at the October 2012 XLR class I attended at Gunsite, so your suggestion here has good corroboration. Marking up the lightscreens with lines sounds like a solid idea too. Thanks again.

 

[K2Ballistics]

Did you resolve the issue? Let us know how you make out.

 

[Starbuck]

Yes, the 25' CAT5e Network Cable did the trick, plus making sure that the lightscreen was reasonably parallel to the trajectory.

Dunno which fixed it, but it's fixed, at least for now. Shot 20 rounds with no issues.

Had the 1K range to myself today at the Colorado Rifle Club. 64F, sunny, 5MPH 9 O'Clock breeze. PVM-21 working again. A beautiful day:

 

[K2Ballistics]

Nice pics. Glad you got it worked out.