Which Chronograph ?

[Iain D]

Here is the way i got my Alpha Chrony to work inside, the light kit is expensive and if you are still close to strip lights it sometimes would show up errors,

So i went to B & Q and gota couple of LED spotlights and fixed them as shown in the picture, I have had no problems since and it only cost £10



Iain D

[18 Wheeler]

Here is the way i got my Alpha Chrony to work inside, the light kit is expensive and if you are still close to strip lights it sometimes would show up errors,

So i went to B & Q and gota couple of LED spotlights and fixed them as shown in the picture, I have had no problems since and it only cost £10



Iain D

Looks good. Minimal work and cost.

Already have some of those lights, which I use for target illumination during the winter, so I'll give it a go. Thanks.

[hareng]

Has any one seen this one http://www.youtube.com/watch?v=M-C_8kyUQbE

Nice find that, which one is the more accurate?

Just because a Chrony tallies up with another at a different location, humidity and a different light dont make it correct when used elsewhere. Manufacturers spend thousands and used in controlled environment.
Also have seen numerous times them reading a good 10% fast 17 years ago.
Even external lighting kits and adaptations would need checking even recalibrating.

Of course the Combro could be out, we dont know. The only way to find out is compare with a known to be good.

Aside from that both run 4mhz which translates to +/-1.5% error each individual shot. That means each individual shot with something running 800ft/sec could give any reading -12 to +12ft sec.

[Mr Magoo]

http://www.youtube.com/watch?v=M-C_8kyUQbE


Wow!.


I have not seen that footage on Youtube before.


Thanks Jonone


So if the combro was reading wrong and your rifle was confiscated by the police and tested


Possibly looking at a prison sentence.


Be Very Careful

[hareng]

Think we will just highlight the problem here.
Buy a new chrono and you cannot take it for granted it will read correct in 'your surroundings'

As we all know light changes, so does the readings!
The only way round it is with Infra Red or use in a controlled environment.

[robinghewitt]

Aside from that both run 4mhz which translates to +/-1.5% error each individual shot. That means each individual shot with something running 800ft/sec could give any reading -12 to +12ft sec.

Hate to disagree but at 800 ft/s the cb-625 clock resolves to around 0.8 ft/s and displays to 1 ft/s.

984 counts = 800.2 ft/s
983 counts = 801.0 ft/s

There are potential faults that can put them out which is why I am a fanatical tester.

Top tip for accuracy has to be "read the manual", they don't work by magic, they depend on you to get the setup right.

If you think you have a problem cb-625 I am not hard to find

Robin

[rogb]

If you have a Combro and you think it is reading low or high, send it to Robin and he will check and adjust the calibration (there may be a small charge for this, depending on its age)

I had mine checked some time back and it is spot on, even after shooting it the other day. It needs some new case parts so maybe it is time to get it checked again.

I have had it since 1996 and wouldn't be without it.

[robinghewitt]

Has any one seen this one http://www.youtube.com/watch?v=M-C_8kyUQbE
Is there realy that much diferance between the two chronys. Jon.

Hmm, F1 reads 967, cb-625 reads 871 ft/s

Sorry to be all mathematical but chronoscopy is all about numbers.

871/967 times the 60mm optical separation on the cb-625 = 54mm, that's 6mm out.

But the cb-625 optics are only 1.5mm wide

If I wanted to get that result I think I'd remove one of the metal sunfilters from a photodiode and set up a false optical path. Perhaps it happened at the same instant he lost one segment on the LCD

I'm not saying the cb-625 can't be that far out, a dud capacitor could do it, it is, however, unlikely.

Robin

[Airsporter1st]

http://www.youtube.com/watch?v=M-C_8kyUQbE


Wow!.


I have not seen that footage on Youtube before.


Thanks Jonone


So if the combro was reading wrong and your rifle was confiscated by the police and tested


Possibly looking at a prison sentence.


Be Very Careful

If the combro was wrong and if your gun was over and if you were pulled whilst going about your lawful pursuit and if your gun was tested......

This is just scaremongering.

How many responsible airgunners do you actually know that have been handed down a prison sentence solely for being over the limit?

[Mog]

If the combro was wrong and if your gun was over and if you were pulled whilst going about your lawful pursuit and if your gun was tested......

This is just scaremongering.

How many responsible airgunners do you actually know that have been handed down a prison sentence solely for being over the limit?

Non, but not every responsible airgunner necessarily is a member of a forum and knows about chronos. IMHO all retailers, when selling an airgun to a newbie, should advise them to get one. The cb-625 is probably the most important and best VFM airgun accessory available.

[robinghewitt]

I just watched that video again, according to the cb-625 his spread is 869 to 872. According to the Alpha it is 967 to 979.

Looks like a nice gun and as shot to shot consistency is the first thing to go out the window when cb-625 has a problem I think it is probably reading true

[Raygun]

Wonder if the Chrony if folded right out ?

If not it would give a higher reading as it would be measuring over a shorter distance. Or have I got that wrong.

ATB
Ray.

[SpikeG]

Wonder if the Chrony if folded right out ?

If not it would give a higher reading as it would be measuring over a shorter distance. Or have I got that wrong.

ATB
Ray.

Spot on Ray, it would be higher.

My F1 always reads high (consistently 30fps) if I don't fit the shades.
Put them on and it compares very closely to the others I tried it against.

[JamesB]

I never imagined my simple question would be answered in such depth!

Anyway, Does anyone know if skan are still trading? no answer on the phone all day. So might be a Chrony after all.

James

[Airsporter1st]

I never imagined my simple question would be answered in such depth!

Anyway, Does anyone know if skan are still trading? no answer on the phone all day. So might be a Chrony after all.

James

I think they're a bit of a one man band! I have a Skan Chrono and I just hope it never goes wrong.

Still very happy with it though.