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Tom_o
Tinkerer
Username: Tom_o
Post Number: 1
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 01:39 pm: | 
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Is there a battery that can be substituted for the Konica Autoreflex T3's original mercury batteries, which can no longer be used? |
Charlie
Tinkerer
Username: Charlie
Post Number: 100
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 03:34 pm: |
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What is the original batteery called for in the users manual? |
Mndean
Tinkerer
Username: Mndean
Post Number: 25
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 03:52 pm: |
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If it uses. as I see on a website, the mercury PX675 button cell, you do have a substitute that will work. There is an identical size zinc-air hearing aid battery that will fit in the battery chamber and will give you close to correct readings. The voltage difference is small - 1.4 for the zinc-air, 1.35 for the mercury. Problem is that they require exposure to air by pulling a tab and giving them time to activate, usually 30 minutes. Worse than that, they only last a few months whether used or not. However, they are quite cheap and are the easiest solution for your Konica. Using either silver or alkaline cells of that size will not give correct meter readings (alkalines are especially bad and not recommended), and you must use other means, either meter recalibration (requires disassembly, but will allow you to use long-lived silver-oxide cells) or inserting a voltage dropping diode (again, requires disassembly) to get close to correct meter readings. |
Mndean
Tinkerer
Username: Mndean
Post Number: 26
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 04:00 pm: |
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Sorry I was unclear - I meant to say, once you pull the tab of a cell and put in the battery chamber, it will only last a few months. As long as the tab stays on, it can be safely stored for a long time. |
Tom_o
Tinkerer
Username: Tom_o
Post Number: 2
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 05:12 pm: |
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Mndean - Thanks for the information. Do you know the brand or part no. of the hearing aid battery? Should I assume that recalibration is not something to be tried at home? Is it expensive to have done? |
Mndean
Tinkerer
Username: Mndean
Post Number: 27
Registered: 08-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 05:53 pm: |
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As far as brand or part number, I don't know it, but they are widely available - check drugstores and the like. Take the old battery with you to match the size.
Recalibration requires employing a knowledgeable tech at a fair price, or a fearless attitude and an ability to look at a dismembered, broken camera philosophically. Along, of course, with some directions in how to do the recalibration in the first place. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 386
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 06:14 pm: |
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The part number is 675. There are several brands, you can find them at any pharmacy including the pharmacy counters at discount stores.... they are sold as hearing aid batteries, in multi-packs of from 4 to 12 or so in a pack. Typically the cost is about $1 per cell depending on how many are in the pack, and as Mndean mentioned, they store very well in their original sealed condition. Typical life in the camera is 3-6 months, but I've had one last a LOT longer... over 2 years in an OM-1 (no idea how that happened and I'm sure I'll never get that lucky again) |
M_currie
Tinkerer
Username: M_currie
Post Number: 77
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 27, 2007 - 08:08 pm: |
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I have found with my T3 that hearing aid batteries work well with an offset of two thirds of a stop (two clicks down on the ASA dial). So, for example, for ISO 100 film, set it to 64, for 400 set it to 250, and so on. The offset is the same for any film speed. You can confirm the offset for your own camera by performing a battery check and just moving the ASA dial until the needle is right. Very fresh batteries may vary a little, so recheck after a day or so.
In case you have no instructions, the battery check is: lens off, ASA 100, shutter at 125, push on-off switch to left: needle should center in the red band between 8 and 11.
I get about 3 months for a set of batteries, except when the T3 kicks around in the car a lot. It has a tendency to turn itself on, so I always keep spare batteries handy.
Unfortunately, the T3 is too voltage sensitive to do well with alkalines or silver oxides. With silver oxide cells, the offset is from 100 to 12, making slower film an obvious problem.
Hovaness, a frequent contributor to this forum, has in the past given out some instructions for recalibrating a T3. I have not bothered yet to do anything about mine, since it's not my principal camera, and the hearing aid cells work well, but I'm sure he could provide the procedure to anyone interested. |
Tom_o
Tinkerer
Username: Tom_o
Post Number: 3
Registered: 09-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, September 28, 2007 - 12:16 pm: |
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Thanks for all the comments. I got the 675s and they work great. An otherwise reputable camera shop had told me years ago that there was no effective battery replacement and that the camera was essentially obsolete - might they have been hoping I'd buy a new one? I'm glad I finally dug it out of the closet and decided to try again. |
Hovaness
Tinkerer
Username: Hovaness
Post Number: 46
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 01, 2007 - 07:22 pm: |
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The recalibration for silver cell voltage is not a big deal if you are comfortable taking the top off the camera. The two adjustments required (1 potentiometer and 1 linkage positioning screw) can be made without further disassembly once the top cover of the t3 is removed.
The T3 is a fine rugged beast of a camera and good samples are selling for scandalously low prices on eBay. It is well worth restoring this model, because the shutters tend to stay accurate and the lens quality is superb. |
Reborn7
Tinkerer
Username: Reborn7
Post Number: 9
Registered: 11-2007
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 28, 2007 - 07:51 am: |
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Hello Hovaness,
can you give more information on disassembling the top cover and more details on the adjustments needed ? |
Hovaness
Tinkerer
Username: Hovaness
Post Number: 60
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, December 30, 2007 - 08:30 am: |
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To take the top cover off, you will need a friction tool to get the cap off the win lever and a small pin face tool to unscrew the shutter speed dial retainer. The Rewind knob unscrews in the conventional fashion. I have attached some information on the adjustment locations for the meter calibration. |
T3 Meter Calibration drawing
T3 Potentiometer Identification