PACT Chrono malfunction?

[DonMountain]

I bought a PACT Chronograph about 20 years ago when I first got into casting boolits. Then stopped shooting for about 10 years and didn't use it at all. Until recently. After getting back into casting boolits and reloading again I cleaned up the PACT Chronograph and got it working again. Until last week. I left it out in the barn and a ground hog bit off one of the sensor wires. I carefully stripped the shielded wire ends back and soldered them back together and used heat shrink tubing to carefully seal up the center wire and then overtop the shielding wire on the outside. Both soldered back together and insulated from each other. But the Chronograph doesn't work anymore. Or could it be an operational problem as my previous successful shooting was all done on overcast days, and this time when the failure to read velocities occured on a really bright, sunshiny day?

[Larry Gibson]

Ahhhhh.....a slick variation of " the dog ate it" excuse......come on now, how did you shoot the sensor wire????????

:kidding:

Probably going to need a new sensor wire :drinks:

Larry Gibson

[trixter]

just an opinion, but do the wires have a certain resistance they need to function ?

[376Steyr]

Bright, sunny days with the sun coming in at odd angles can really mess with the photo detectors seeing the bullet go over them. I try to take a .22 with me to make sure everything is working right before I start burning up my expensive ammo.

[DonMountain]

I had a suspician the bright sunlight may have been the problem instead of my "fix" on the wire that was bitten off by the "dog" or boolet. I just now set a live trap to resolve the ground hog problem (so my wife's cat doesn't get killed.) Although I had assigned the 18 year old grandson to look after the ground hogs. But he has been too busy getting ready for Turkey season. So, in really bright sunlight what is the methods of making the chronograph work? I think now I had this trouble years ago with it too.

[DonMountain]

just an opinion, but do the wires have a certain resistance they need to function ?

I wondered about that also. From experience with working on oil pressure temperature sending units on airplanes. But this system looks like a photocell that probably generates a voltage with a slight drop when the shadow of a boolit triggers the unit. And the voltage would be varying over a wide range due to different light conditions anyway. So I thought it wouldn't need a measured, constant resistance to operate the gage like the oil pressure would. The wire looks to be maybe a 28 gauge copper wire core with a copper shielding around it. And I only shortened it maybe a half an inch and soldered it after carefully wrapping the ends together. Maybe someone else knows more about this?

[DonMountain]

Ahhhhh.....a slick variation of " the dog ate it" excuse......come on now, how did you shoot the sensor wire????????

:kidding:

Probably going to need a new sensor wire :drinks:

Larry Gibson

I don't have a dog. So it must have been that darn cat my wife has. I hate cats! But worse then that I hate being late for supper! By the way, does anybody have a good recipe for ground hog?:popcorn:

[popper]

Plain ol copper wire with shielding wire around it? Make sure the shield doesn't connect to the core wire. It could also be coax (would need to be replaced) to handle the high speed really low level signal. Check that the photo detector isn't miss-aligned and is clean.

[shooting on a shoestring]

My Oehler uses a diffuser over each sensor. Its nothing more than an orange piece of plastic that diffuses the direct sunlight. I don't use them on overcast days. Could be your problem. I think a plain ole piece of copy paper shading your sensors just might work. Or try it in early morning or late day when the sun is at a shallow angle.

[hyoder]

Go to Radio shack and purchase two microphone extensions cords. The ends should be the same as the cords on the sensors. Open the sensors and replace the cords. You'll need a low wattage, 15 w prefferibly, 25 will do if you are careful, soldering iron. Worked for my Pact Model 1.

[DonMountain]

I have diffusers over the photocells now. So I will try shooting over it on a cloudy day to see if that makes it work. Then I will try a microphone cord from Radio Shack to replace the bitten off one. Although I am not sure we have one of them around here.

[Mal Paso]

Sometimes Bright sunlight hitting the ground under the chronograph is picked up by the bullet reducing or eliminating that shadow that you're trying to read. Try a black or dark cloth on ground under the chronograph. That Idea came from Dillon.

Here's what I did. http://castboolits.gunloads.com/showthread.php?t=95846

It made that Chrony 100% reliable. A nice shiny boolit polished by the bore can be hard for the chronograph to see.

[DonMountain]

Thanks a lot for this info. I think this may be my solution right here. Now I need to find some lightweight black panels to resolve the issue.

[DonMountain]

I took the Chronograph out early this morning and set it up in the shade of the barn roof and fired 5 round through it and got successful readings. I checked the target and walked back and fired 5 more through it and it gave me some errors and no more readings. So, its back to work on fixing the problem. I haven't tried the black side panels yet.

[BLTsandwedge]

I took the Chronograph out early this morning and set it up in the shade of the barn roof and fired 5 round through it and got successful readings. I checked the target and walked back and fired 5 more through it and it gave me some errors and no more readings. So, its back to work on fixing the problem. I haven't tried the black side panels yet.

That's precisely what Mal Paso and I experienced. Either chrony would work for maybe two five (5) shot strings and then would start the error messages. Seems Mal Paso's fix was just that- a good fix. I doubt it is a panacea but it did good by us.

[goofyoldfart]

DM (as per #7) : Ground Hog (aka Roast Beef Stew to the ex-wife) is easy to fix.

Inasmuch as it is a strict vegetarian, it makes a great stew. 1) Do a parboil (do clean and skin said hog :kidding:) in a large stew pot for about 3 times. this cleans the meat and also kills any bugs. change the parboil water 3 times. Let cool and then strip the meat from the bones and set aside. in a large pot (figured for the size of 2 servings per person--your family) start a vegetable stew stock. I use carrots, potatoes, mushrooms, turnips, onions and celery. use the amount that will get you the desired amount for the servings you want. for a quick cook use a pressure cooker--if not that, figure about 1 hour cooking. Add said save meat from said "chuckie" and add spices to flavor. I tend to use a beef base, a little Cajun pepper or hot sauce, Garlic, salt and pepper to taste and a little Italian spice. you KNOW what your tongue and taste buds like--go with that. bring to a boil for about 5-10 minutes then let simmer for about 1 hour. About 15 minutes before done, put 1 cup of a good Sherry or Port of your flavor and turn the heat up between simmer and boil. (I do this to burn off the alcohol in that I'm a recovering Alki--31yrs sober). I you can drink, well go ahead and serve as soon as you add the booze:grin::wink:

should add that parboiling is a HARD ROLLING BOIL. About 15-20 minutes each. total time should be ABOUT 2hrs total (give or take 30mins depending on your kitchen acuity. Put in bowls and totally enjoy--you may even forgive the poor critter for chewing you cable.:grin: If you leave out the potatoes, you can put it over a rice pilaff. OH YEAH--don't forget to skin and clean Chuckie before you parboil it.:kidding: Hopes this helps. I fed it to my ex for 3-4 yrs before she found out it WASN'T Roast Beef Stew. NO, she's not my ex for feeding her this--'Twer my being an Alkie. her leaving with the kid help me make the decision to get sober and now we are friends.
God Bless to all and theirs.

[Mal Paso]

I took the Chronograph out early this morning and set it up in the shade of the barn roof and fired 5 round through it and got successful readings. I checked the target and walked back and fired 5 more through it and it gave me some errors and no more readings. So, its back to work on fixing the problem. I haven't tried the black side panels yet.

Just a thought. Have you cleaned the sensors? Canned air or lens cleaning cloth or brush works.

[DonMountain]

Yes, I have cleaned the sensors. And looked at them again before I did this shooting test and they still appear to be clean. Its raining today so I will work on making the black panels for it. And reforming old 30-06 casings to 8mm Mauser.

[Mal Paso]

I figured you had cleaned them after the care you took with the splice. All that matters is a good connection (can be tested with a meter). Coax cable has Impedance but that isn't a concern here.

I don't think Ground Hogs have the right teeth but I've had rats bite through wires with those needle teeth and cut the copper wire but leave the plastic insulation intact. An Ohm Meter would tell.

The more contrast you can create for the sensors the better. Some of my research indicated one of the top chronograph manufactures sensors trip on flash as well as shadow to improve reliability.

[DonMountain]

I figured you had cleaned them after the care you took with the splice. All that matters is a good connection (can be tested with a meter). Coax cable has Impedance but that isn't a concern here.

I don't think Ground Hogs have the right teeth but I've had rats bite through wires with those needle teeth and cut the copper wire but leave the plastic insulation intact. An Ohm Meter would tell.

The more contrast you can create for the sensors the better. Some of my research indicated one of the top chronograph manufactures sensors trip on flash as well as shadow to improve reliability.

Maybe thats why I don't ever see groundhogs out by the barn. But lots of holes in the barn. I got rats instead of ground hogs. Gotta get the rat traps out and hope I don't catch my wife's cat. And on the sensors, are they just photo cells and can I put a volt meter across the terminal on the plugs that go into the back of the computer unit and read a voltage? And compare the two to see if the wiring is similar? I will have to go try that and answer that myself. Although I bet the voltage output is really small. But how small to expect?

[Mal Paso]

Yes they are photocells. If your meter reads ohms set it to the lowest Ohms setting and touch the probes to opposite ends of the center conductor of the cable. You should get a reading very near 0 or 1. Do the same with opposite ends of the sheath as it is a conductor too. Harbor has meters on sale for $3.99. They work well enough for 95% of all electrical work.