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Railcrew
Tinkerer
Username: Railcrew
Post Number: 70
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, April 03, 2013 - 11:44 pm: | 
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I'm wondering whats wrong with my meter on my C35? I had corroded wires throughout and replaced them, now the meter gives false readings like pegged all the way up on an overcast day (1/640 @ f:14) It was hacked before I got it and I'm not sure if it is missing a key part. Is there supposed to be some kind of resistor between cds and the meter? Mine has none. If so what kind? Also a wiring diagram would be nice. |
Neuberger
Tinkerer
Username: Neuberger
Post Number: 79
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 04, 2013 - 02:53 am: |
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.. the magic word is ARCHIVES, look here, for example: https://kyp.hauslendale.com/classics/forum/messages/2/25441.html |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 519
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 04, 2013 - 08:17 pm: |
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It would depend on what type of battery you are using if a resistor is required. 675 zink-oxide should be okay, as they are just 1.4v. A 357 is too much at 1.5v.
PF |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 435
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 04, 2013 - 08:25 pm: |
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If the meter is spiking, it could also mean a dead cds cell. |
Railcrew
Tinkerer
Username: Railcrew
Post Number: 71
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, April 04, 2013 - 09:28 pm: |
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(Neuberger, I did a search for "Konica C35 wiring" and must have missed that one, thanks)
(Br_ I'm using a 1.4 zinc air...)
This is why I'm so perplexed... At first, after the repair the meter was working fine. After sitting a few weeks, getting ready for a trip, I put the (same) battery in and the needle only went up just out of the red zone (1/30 sec) even pointed at my work light. I thought it might be a dying battery so I put in a 1.5 and it too sat there, all of a sudden (after re-inserting the 1.5 battery) it jumped up but not pegged, it was somewhat where it should be according the given light. I then switched back to the 1.4 and it was perfect. after a day or so I got the camera out to shoot and it was pegged full at just what was an EV 13 light situation. I fiddled around with the battery and it dropped again to proper setting. (I would take the battery, cap off, and put it in and out with my finger making the needle go up and down until it set properly) this led me to believe it needed to be "coaxed" for what ever reason because it does eventually work but what a pain... any ideas on what it could be? still a bad CDS? |
Neuberger
Tinkerer
Username: Neuberger
Post Number: 80
Registered: 01-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 05, 2013 - 04:14 am: |
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All the typical problems are mentioned in the thread, that is why I posted the link.
I have several of those cameras plus a number of its clones, and one of the C35s behaved exactly like the one you have. To be honest, I never really found the mistake, but as this particular camera was in very fine shape, I ripped out all the wires plus the photo resistor and put in new ones and a CdS-cell from a cosmetically shabby donor camera, from then on everything was, and still is, perfect. Wiggling and playing with the ripped out parts revealed several weaknesses in the cell itself, but not only the wires had broken strands inside, also the meter coil and its soldering joints showed intermitting contact, faulty parts are hard to trace inside a camera and soldering can go bad after decades. Although the C35 has a very solidly looking meter it is prone to developing issues, just like that in the Taron Marquis or of the early Minolta Hi-Matics. |
Railcrew
Tinkerer
Username: Railcrew
Post Number: 72
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 05, 2013 - 10:02 am: |
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Neuberger, throughout the articl, it is saying the CDS is the resistor,...(snip)"that go to the cds photo resistor"... and ..(snip)" identifying stampings on the CdS cell body before you do your search"...
You're saying CDS and resistor are 2 different things...(snip)"I ripped out all the wires plus the photo resistor and put in new ones and a CdS-cell"..., so what is correct? is there a resistor other than the CDS cell, or IS the CDS cell also the resistor? Some clarity would be of great help, thanks. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 520
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, April 05, 2013 - 04:54 pm: |
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Rich, the CdS Photocell is properly referred to as a photoresistor. The CdS name refers to what it is made of (Cd=Cadmium, S=Sulfide), with other types known by their physical make-up. Here's some light reading on the subject.
http://en.wikipedia.org/wiki/Photoresistor
Sometimes, when a higher voltage battery is used in the circuit, an additional resistor needs to be added to compensate for the extra voltage. So that would give you two resistors in series, with the second one preferably being an adjustable (potentiometer, or "pot") type, to be able to fine tune the circuit.
PF |
Railcrew
Tinkerer
Username: Railcrew
Post Number: 73
Registered: 03-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 07, 2013 - 12:26 pm: |
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Thanks Phill |
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