When first I started using the Oehler, many years ago, it became evident that the supplied battery ( 9volt rectangle ) was really inadequate for extended service especially when using the printer.
Since for what I do the printer wasn't needed much so I switched it off.
Concurrently I built two battery power supplies; one C size for me and one D size for my buddy.
The extended life of the units have increased many fold. roger

Funny enough, I was thinking of this a while back.

We sometimes run out of battery so fast, I but them by the dozen!!

When I get time, I might actually build a power supply for it.

Especially now that I have modified it to take a larger paper roll.

think I got a suitable power supply.

When I do it I will post pictures

I bought my 35P without a printer. Without a printer the standard 9V battery does fine. One tip I can add from experience, my chrono was acting weird not reading shots, strange numbers, sensitive to vibration, and by wiggling the plugs of the skyscreen it would give strange readings. Called Oehler and they said to polish the metal of the skyscreen plugs. Said that oxidation (that you can't even see) would cause problems. I polished the plugs and it's 100% again. Don't use any abrasive. Rep said use leather or coarse cloth to polish with.

Many years ago, after buying my new 35P, I decided to make use of the "spare" battery position.

I accessed the main circuit board, and added a new battery harness in parallel with the factory battery power supply......i.e. doubled the factory battery supply capacity.

It's worked well, lo these many years.

The printer......is another story.

Kevin

Well, I did try a power supply, sadly it does not work.

The chronograph works fine, but, I am unable to stop it advancing the paper.

I think this is caused by the frequency of the power supply - although it is actually a few feet away, and only the cable is connected to the chronograph.

Back to battery power, and will try another power supply.

quote:

Originally posted by Saeed:
Well, I did try a power supply, sadly it does not work.

The chronograph works fine, but, I am unable to stop it advancing the paper.

I think this is caused by the frequency of the power supply - although it is actually a few feet away, and only the cable is connected to the chronograph.

Back to battery power, and will try another power supply.

If you're using an AC to DC power supply you probably need a reasonably large capacitor from the DC out put to ground and a fairly high resistance bleeder resister.It might not hurt to mount it in a mild steel grounded case. Hang in there it will work with a little effort. roger

Never saw the need of the printer as it is simple to jot down the individual shot velocities as they are fired if you wish. Every sort of calculation can then be done after you're finished shooting. Sometimes it is years between the times I need to replace the 9V "transistor radio" battery in my Oehler 35.

quote:

Originally posted by Stonecreek:
Never saw the need of the printer as it is simple to jot down the individual shot velocities as they are fired if you wish. Every sort of calculation can then be done after you're finished shooting. Sometimes it is years between the times I need to replace the 9V "transistor radio" battery in my Oehler 35.

Totally agree with you on the printer. I turned it of before building the battery power supply. The 9 volt "transistor battery" still had to be replaced once or twice a year. Not long ago I was spending about 4 to 5 hours a week at the range. I think that's a lot of hours for that little battery. Today I only shoot about half as much or less and the failure of the larger batteries are of little concern and I think I'm getting more bang ( hours ) for the buck. roger