Oehler 35P false triggers

[Varmint Hunter]

I've got an Oehler 35P which I've relied upon for years. It's a great chronograph and has been surprisingly reliable considering it works off shadows. However, recently it false triggers almost every time I touch the unit. Since I write on the paper while shooting it is false triggering often.

Does anyone know why this is happening? Static? How can this issue be resolved?

 

[warrbuk]

From there website

The source of "False triggers" can be difficult to identify. Some common causes are:

Corrosion or oxidation of the Skyscreen plugs: Use a Scotchbrite pad (not steel wool) and rag with rubbing alcohol to lightly polish the plugs. Once they are clean insert them into the chronograph. Gently rotate the plugs back and forth in the jack to further clean/polish the electrical contact area.
Insufficient light level: The Skyscreens must have open sky above them; they will not work under trees or structures. The orange diffusers are for use under bright/sunny conditions, they should be removed when it is overcast or the sun is low on the horizon.
Electrical interference: Radar towers, electric fences, air compressors etc. have all been known to produce high levels of electrical noise. These items should be turned off if possible; if not possible the light level entering the Skyscreen sensor should be increased. The quickest way to do so is by removing the Orange Diffusers.
If the 35P is to be used indoors proper incandescent lighting must be used. Oehler Skyscreens will not function under fluorescent lights.

 

[Varmint Hunter]

Based on the suggestions, only oxidation on the plugs fits my scenario. I'll give cleaning them a try.

It also identified another problem that I recently noticed. I shoot early in the morning and the sun is very low in the sky on September mornings. Occasionally I was getting no reading or all zeros but noticed that this only happens during the first hour of the morning. I always have the diffusers mounted. I'll try leaving them off and see if there's any improvement.

Thanks for the quick response.

 

[Pdvdh]

Insufficient light can cause false triggering, over and over and over again.

Been there, learned that...

 

[Dean2]

If the suggestions don't fix it call Oehler. They are excellent to deal with and know their gear inside out. They still make the 35P. They will also give it a good going over and fix any issues for a very fair price.


Oehler Research
P.O.Box 9135
Austin, TX 78766
E: [email protected]
Ph: 512.327.6900
Fax: 512.327.6903

 

[Varmint Hunter]

If the suggestions don't fix it call Oehler. They are excellent to deal with and know their gear inside out. They still make the 35P. They will also give it a good going over and fix any issues for a very fair price.

Over the years I've dealt with Oehler's service people on a few occasions. They are VERY helpful and do follow-up calls like a doctor. LOL

Twice I sent the unit back because of erratic readings. I sent the printouts along with the unit. Each time it was bench tested and than actually fired over to confirm its function. They were certain that the unit was working properly. Eventually, it was determined that the factory brake on my RRA 458 SOCOM was actually causing the problems even when the screens were moved back to 15'. I pulled the brake and the unit worked as designed. Go figure?????

I'd bite the bullet and drop $800 for a LabRadar & accessories if the Oehler was problematic but it works great 98% of the time.

 

[Dean2]

Over the years I've dealt with Oehler's service people on a few occasions. They are VERY helpful and do follow-up calls like a doctor. LOL

Twice I sent the unit back because of erratic readings. I sent the printouts along with the unit. Each time it was bench tested and than actually fired over to confirm its function. They were certain that the unit was working properly. Eventually, it was determined that the factory brake on my RRA 458 SOCOM was actually causing the problems even when the screens were moved back to 15'. I pulled the brake and the unit worked as designed. Go figure?????

I'd bite the bullet and drop $800 for a LabRadar & accessories if the Oehler was problematic but it works great 98% of the time.

Brakes cause a lot of problems with Chronographs. Both your own and those in proximity to where a brake is being fired. You often have to set a Chronograph 25 feet away if there are one or more brakes being used on the line.

 

[Varmint Hunter]

Brakes cause a lot of problems with Chronographs. Both your own and those in proximity to where a brake is being fired. You often have to set a Chronograph 25 feet away if there are one or more brakes being used on the line.

I have used brakes on everything from my 460WBY down to a Browning 6.5 Creed without experiencing any issues with the Oehler. Two of my rifles have Vais brakes which have forward facing ports but that never caused a problem either. The massive brake on the SOCOM also has forward facing ports which I believe caused all the erratic readings but because the Vais brakes did not cause a similar degradation of the chronograph output I just never considered that to be a possible cause.

Shooting with the brake on and then off proved, without a doubt, that the brake was the culprit.