FX MK2 Chronograph ?

Forums Other Parts, Accessories, & Equipment FX MK2 Chronograph ?

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    AirgunBill
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    Does anyone know if the FX chronograph can calculate b.c. from just shooting it attached to the muzzle. Bill

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    fe7565
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    The current software does not.  Would it be able to?  I think that FX chrono's reliable measurement range is limited to a few feet only.  Theoretically, the software may be able to be setup to measure the velocity right when the pellet exits the barrel AND again a few feet away from that point.  But the BC calculation would be based on only a distance of a few feet which is not going to give you meaningful numbers.

    If you setup a second FX chrono in front of the target (facing the target), you could get a second (and meaningful) reading of the pellet's velocity.  However, that's pricey and you can get a used Labradar for the price of two FX chronos.  Also, the BC changes during the flight path and you are only able to measure at two points. 

    So the best option is to use a Labradar which tracks the pellet through several predetermined distances and gives you BC calculations on the fly. Or do it the old-fashioned way and setup two or more Chrony's.  Or setup screens that the pellet punches through and measure the drop along the pellet's path….then plug it into Chairgun.   Yrrah from down under did that quite a while back. 

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    AirgunBill
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    Thanks so much fe7565 for the detailed explanation of what the FX's chronographs capability might be. I still think the convenience of the FX chronograph for most work would be worth it. Also since calculating b.c. is not done that often I would just break out my Chrony. Bill

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    fe7565
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    Glad it helped a bit.  Looks like some of Yrrah's old Yellow Forum posts are now archived.  Could not find the one I mentioned: 

    https://www.tapatalk.com/groups/yellow/yrrah-you-got-me-interrested-t234116.html

    https://www.tapatalk.com/groups/yellow/apparent-bc-changes-with-range-to-200-yard-chart-g-t162456.html#p1560325

    • This reply was modified 1 year ago by fe7565.
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    swissarmyknife
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    My experience is that the FX chrono measurement range is very short. During my Crown tuning I had my back stop set only 4 feet away from the muzzle and the chrono read the FPS without an issue which means that it must measure the velocity within less the distance of the 4 feet. I also confirmed this later on the range to make sure that there wasn't a Doppler calculation error and the FPS were still spot on at 45 yards.

    Knowing that it only records speed at such short distance from the muzzle will make any BC calculation extremely inaccurate.

     

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    Raider03
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    I believe the FX chronograph is on (transmitting radar) and waiting for the return signal from the fired pellet. Once that signal is received then a velocity is calculated based on the doppler frequency shift. At stationary object or a slow moving object would not trigger the velocity calculation. The software could wait a specified amount of time and record a second of third doppler frequency data point. The real issue is the power of the radar unit. If the unit has enough power more data points could be collected and used to report velocity down range and calculate pellet BC. Without enough power the return signal will be too low to measure. It does seems from a review that the FX chronograph has a very narrow cone angle on the radar signal as the angle of the unit to the barrel changes the performance. This would also make it difficult to track a pellet at longer ranges.

     

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    fe7565
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    Raider03, yes the power is not enough for longer ranges and the it would also need a horn antenna that focuses the signal in a more narrow cone.  But that cone would be so narrow that the FX Chrono would need to be almost like a scope as far as mounting on the gun to line up with the pellet's path.

    Also, with greater distance their is an angle error that is introduced if the FX Chrono is not aligned perfectly with the pellet's path. I do not think the existing sensor has any angular sensing capability.  And even if it would, do not think the software compensates for that in its current format.

     

     

    • This reply was modified 6 months ago by fe7565.
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    mmahoney
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    The battery life of the FX Chrony is not very long. Upping the power to calculate the BC would make it exponentionally worse. I'm not sure how much further the signal can be amped up to go. It would have to be pretty far to get an accurate BC. If my understanding is correct, BC changes as the velocity of the pellet changes which means a more accurate BC will be made at 100 yards than 10 yards. Look at the size of the LabRadar and even it has trouble with .177 pellets past 50 yards.

    I think the FX Chrony is good for measuring barrel velocity, but limitations in the size of the unit and power requirements make it a poor candidate for a BC calulator. If you really need to know BC, I think the LabRadar is the way to go.

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    ctshooter
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    There are some spec posted on the FX chorny. I think it only reads about 1 foot in front and about 8 inches up and down.

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