More repair videos! Loved the Canon Squeak repair. That baggie of 1N34As looked more like Schottky diodes in a glass package. The less scrupulous sellers on eBay pass them off as Germanium. Schottky diodes (signal switching diodes, not power) have a 0.2 volt drop. They are also way cheaper than Germanium and easier to find. 1N5711, 1N6263, NTE583, 1N5817-5721 (higher current rating)
Very good information to have, the list of possible workable diodes for the meter modification procedure should be helpful. Sometimes we just might use a multi-meter with a Diode Test mode to determine the voltage drop of our diode before installation. The Diode Test mode produces a small voltage between test leads. The multi-meter then displays the voltage drop when the test leads are connected across a diode when forward-biased. We set the multi-meter to the Diode Test mode. It can share a space on the dial with another function. Connect the test leads to the diode. Record the measurement displayed. Reverse the test leads. Record the measurement.The multi-meter displays OL when a good diode is reverse-biased. The OL reading indicates the diode is functioning as an open switch. The multi-meter will give additional information about the diode. A bad (opened) diode does not allow current to flow in either direction. The multi-meter will display OL in both directions when the diode is opened. A shorted diode has the same voltage drop reading in both directions. Anyway thank you for the comments and your interest in FOC.
@@FixOldCameras Coming from the Crystal Radio hobby, it is easier to spot these things; whether from ignorance or fraud on the sellers' part. Another eBay one to watch out for is the 1N 60 P (note spaces) Germanium 7mm long diode and the 1N60P Schotty 4 mm long silicon diode. Any small signal Schotty should work for the one battery (1 or 2 diodes in series) and any small signal silicon for the 2 battery. You could use Schottkys in series to fine tune a 2 battery meter. Digikey and Arrow are two mainstream parts suppliers that can be trusted and have excellent customer service.
Hi! How can one tell the difference between genuine germanium and knock off please? I can order 10 1n34a germanium for relatively cheap but I don't want to do an half ass adjustment to my OM1 :) Thank you!
@@jd5787 Do a search for crystal radio website, blogs, and forums. There will be a section or article for beginers on diodes. A real germanium is a point contact style. They only come in a glass package. There is a fine wire connecting the two leads together. This is a cat's whisker and the best vintage diodes ised a gold wire.
I had a problem with my Olympus om1 and i was looking for a diod which can be equal to the germanium one, mentioned in your video , but then i found an article on russian which describes the meter adjustment for regular 1.5v batteries (lr44 or 625a). Then I bought the new 1.5v battery and realised that my camera had already been adjusted and it gives me the right exposure without the lost of sensitivity, caused by the extra element in the metering system. I didn't found such an information in English , so it can be very useful for many people, i can send you the link , if you are interested in creating such a video, i believe you can make it the greatest way. Sorry for my english , I'm russian
Much going on here in FOC land... will try to make a video post every 4 to 6 weeks. Thank you for the comments. "The Camera Craftsman" was a cool title for a camera repair magazine and later "The New Camera Craftsman" for the news letter. According to the Mirriam-Webster English Dictionary, the definition of craftsman is: a worker who practices a trade handicraft or one who creates or performs with skill or dexterity especially in the manual arts... Never seen a list of trades that included camera repair and it is surely not a handicraft. But camera repairing just take might take a bit of skill and dexterity of the fingers. Anyway, thank you for your continued support of Fix Old Cameras.
Only a working knowledge as to the how, with little understanding as to the why. But with that said... a resistor resists current (amps) from flowing in a circuit. A resistor decreases current not voltage. But experience also shows how much voltage appears across the resistor also depends on how it used in the circuit and what other components are involved.
A resistor limits current, not voltage. There will be a voltage drop across the resistor but you dont want to get rid of the current. A diode only has a voltage drop and being a semiconductor reduces the current only a tiny amount due to its low resistance.
Hi, I thought my MR9 adapter was not working as I also tried to measure the voltage drop when it and the battery were out of a camera. However, it worked fine when connected to the camera (top of camera was off so a meter could be used). I believe the diodes in these devices need a certain amount of mA flowing in order to reach the specified Voltage drop. Understand that putting a c.10kilohm resistor across it then measuring is one way to represent this ‘load’. But absolutely no expert!
I know the clip is old and stuff but if you are still around, I have a Konica T3 that used 2 mercury PX675. Is the diode 1n4007 still recommended? Thanks in advance @fixoldcameras
Unfortunately I do not understand the names correctly. Could you perhaps make a short list which resistors you would use for the respective area? Thanks a lot!
How are you measuring the voltage drop? I have a Fluke meter and when I use the diode test every one of my ECG109's have a .24 and higher drop. A package of IN34A diodes all measure .31 I'm using a Sperry DM-350 meter which is similar to yours as a second choice over the Fluke. I wonder if the forward voltage is dependent on the current? I guess my best bet would be as you said and just try them out.
I have a Minolta Hi-Matic G that I purchased recently and found the wire connected to the light meter has a corroded diode that is in readable. I can’t seem to find any information on what one I can use to replace it. Do you have any suggestions on what I can use to replace it or how to find out. I have pictures if you would need a visual guide.
Diode are fairly forgiving try determine the types of diodes behave differently, short of accessing another Hi-matic, trying a diode substitute should do no harm. A good forward-based silicon diode displays a voltage drop ranging from 0.5 to 0.8 volts for the most commonly used silicon diodes. Some germanium diodes have a voltage drop ranging from 0.2 to 0.3 volts. The ECG109 seems to consistently run a drop of 1.6 voltsThe multi-meter displays OL when a good diode is reverse-biased. The OL reading indicates the diode is functioning as an open switch. The multi-meter will give additional information about the diode. A bad (opened) diode does not allow current to flow in either direction. The multimeter will display OL in both directions when the diode is opened. A shorted diode has the same voltage drop reading (approximately 0.4 V) in both directions.If you have a multi-meter with a Diode Test mode you can determine the voltage drop of your diode before installation. The Diode Test mode produces a small voltage between test leads. The multi-meter then displays the voltage drop when the test leads are connected across a diode when forward-biased. The Diode Test procedure is conducted as follows: If you are checking in circuit make certain no voltage exists at the diode. Voltage may be present in the circuit due to charged capacitors. Other wise, set your multi-meter to the Diode Test mode.It may share a space on the dial with another function. Connect the test leads to the diode. Record the measurement displayed. Reverse the test leads. Record the measurement. Compare results Why not a resistor? Well... a resistor resists current (amps) from flowing in a circuit. While it is doing this, a voltage will appear across the resistor. How much voltage appears across the resistor depends on what other thing are in the circuit resisting current to flow. So a resistance fundamentally decreases current not voltage.
Ok, my reading on this is that indeed combinations of diodes can indeed be used and work as I suggested, voltage drop is combined for two diodes in series. So a diode dropping voltage 0.1v with a seconded dropping voltage 0.1v would result in a total drop of 0.2v. That means 1.5v would go to 1.3v. Voila. I realize there must be some reason this isn't done, but I want to know why. I sure would like to do this to all my cameras but it would be expensive using the Ecg109 diodes. A lot of diodes are just pennies. Some electrical engineer needs to get on this.
So I see the "M9" that is not actually the M9, and a few trying to look like it, but none that actually drop the voltage. The Canon EF I discovered has a voltage regulator. (Much to my delight at the time). Are there noteworthy cameras which also have a regulating circuit so that the alkaline 1.5 cell works? I just put in my order for both types. My challenge is the Canon (Bell & Howell) Dial 35. AKA Dial 35-2. Is this feasible I wonder? Been done?
Maybe you can help me with this one. I've got a Minolta Hi-Matic E Rangefinder (fully program mode) which requires two PX645 1.35v mercury batteries. I've used two 675 zinc air batteries but ran into several concerns. First, they don't last too long. Second, on this camera, when there is sufficient lighting the light in the viewfinder is green. When the lighting requires less then 1/30 SS, it starts green then turns red. With the 675 batteries, you'll never see the red light. I want to use 357/303 1.5v batteries but don't know how this will affect the exposure. I've read that it has a bridge circuit. Do I need a mod, or can I simply use 1.5v without issue? Thanks.
@@abbas1872 thanks. I ended up bridging two diodes in the battery compartment along with two 1.5v batteries. Worked great, until the camera kicked the bucket. RIP camera. 😢
More repair videos! Loved the Canon Squeak repair. That baggie of 1N34As looked more like Schottky diodes in a glass package. The less scrupulous sellers on eBay pass them off as Germanium. Schottky diodes (signal switching diodes, not power) have a 0.2 volt drop. They are also way cheaper than Germanium and easier to find. 1N5711, 1N6263, NTE583, 1N5817-5721 (higher current rating)
Very good information to have, the list of possible workable diodes for the meter modification procedure should be helpful. Sometimes we just might use a multi-meter with a Diode Test mode to determine the voltage drop of our diode before installation. The Diode Test mode produces a small voltage between test leads. The multi-meter then displays the voltage drop when the test leads are connected across a diode when forward-biased.
We set the multi-meter to the Diode Test mode. It can share a space on the dial with another function. Connect the test leads to the diode. Record the measurement displayed. Reverse the test leads. Record the measurement.The multi-meter displays OL when a good diode is reverse-biased. The OL reading indicates the diode is functioning as an open switch. The multi-meter will give additional information about the diode. A bad (opened) diode does not allow current to flow in either direction. The multi-meter will display OL in both directions when the diode is opened. A shorted diode has the same voltage drop reading in both directions. Anyway thank you for the comments and your interest in FOC.
@@FixOldCameras Coming from the Crystal Radio hobby, it is easier to spot these things; whether from ignorance or fraud on the sellers' part. Another eBay one to watch out for is the 1N 60 P (note spaces) Germanium 7mm long diode and the 1N60P Schotty 4 mm long silicon diode.
Any small signal Schotty should work for the one battery (1 or 2 diodes in series) and any small signal silicon for the 2 battery. You could use Schottkys in series to fine tune a 2 battery meter. Digikey and Arrow are two mainstream parts suppliers that can be trusted and have excellent customer service.
@@Pixelwaster Even more excellent information. Very helpful. Thank you.
Hi! How can one tell the difference between genuine germanium and knock off please? I can order 10 1n34a germanium for relatively cheap but I don't want to do an half ass adjustment to my OM1 :) Thank you!
@@jd5787 Do a search for crystal radio website, blogs, and forums. There will be a section or article for beginers on diodes. A real germanium is a point contact style. They only come in a glass package. There is a fine wire connecting the two leads together. This is a cat's whisker and the best vintage diodes ised a gold wire.
I had a problem with my Olympus om1 and i was looking for a diod which can be equal to the germanium one, mentioned in your video , but then i found an article on russian which describes the meter adjustment for regular 1.5v batteries (lr44 or 625a). Then I bought the new 1.5v battery and realised that my camera had already been adjusted and it gives me the right exposure without the lost of sensitivity, caused by the extra element in the metering system. I didn't found such an information in English , so it can be very useful for many people, i can send you the link , if you are interested in creating such a video, i believe you can make it the greatest way.
Sorry for my english , I'm russian
Thank you for your comments and your interest in FOC.
Hello, you could enter this information or link yourself !!! thank you
Welcome back, it's always nice to see a new Fix Old Cameras episode. I have that Camera Craftsman newsletter somewhere. I was a subscriber in the day.
Much going on here in FOC land... will try to make a video post every 4 to 6 weeks. Thank you for the comments.
"The Camera Craftsman" was a cool title for a camera repair magazine and later "The New Camera Craftsman" for the news letter.
According to the Mirriam-Webster English Dictionary, the definition of craftsman is: a worker who practices a trade handicraft or
one who creates or performs with skill or dexterity especially in the manual arts...
Never seen a list of trades that included camera repair and it is surely not a handicraft. But camera repairing just take might take a bit of skill and dexterity of the fingers. Anyway, thank you for your continued support of Fix Old Cameras.
THANK YOU VERY MUCH FOR THIS VIDEO!!!
Thank You for all your great Knowledge Boss. Always Appreciated and cherished.
Thank you for your kind comments and for you continued interest in FOC.
I really enjoy your channel. Great infos here!
But, sorry to say, with one exception... Your soldering joints...
Sorry for my lack of electronics knowledge, but why is a resistor not a candidate to reduce the voltage?
Only a working knowledge as to the how, with little understanding as to the why. But with that said... a resistor resists current (amps) from flowing in a circuit. A resistor decreases current not voltage. But experience also shows how much voltage appears across the resistor also depends on how it used in the circuit and what other components are involved.
A resistor limits current, not voltage. There will be a voltage drop across the resistor but you dont want to get rid of the current. A diode only has a voltage drop and being a semiconductor reduces the current only a tiny amount due to its low resistance.
did you ever see a germanium diode with 2F written inside the top band and then a solid black band underneath? I need to know what it is
Hi, I thought my MR9 adapter was not working as I also tried to measure the voltage drop when it and the battery were out of a camera. However, it worked fine when connected to the camera (top of camera was off so a meter could be used). I believe the diodes in these devices need a certain amount of mA flowing in order to reach the specified Voltage drop. Understand that putting a c.10kilohm resistor across it then measuring is one way to represent this ‘load’. But absolutely no expert!
Thank you for your commenting on your experience with the MR9 adapter.
I know the clip is old and stuff but if you are still around, I have a Konica T3 that used 2 mercury PX675. Is the diode 1n4007 still recommended? Thanks in advance @fixoldcameras
Unfortunately I do not understand the names correctly.
Could you perhaps make a short list which resistors you would use for the respective area?
Thanks a lot!
Diodes for classic camera meter modification.
ECG109 - OA90 - SK3090 (single battery meter systems)
1N4007 - DO-41(double battery meter systems)
How are you measuring the voltage drop? I have a Fluke meter and when I use the diode test every one of my ECG109's have a .24 and higher drop. A package of IN34A diodes all measure .31 I'm using a Sperry DM-350 meter which is similar to yours as a second choice over the Fluke. I wonder if the forward voltage is dependent on the current? I guess my best bet would be as you said and just try them out.
Right on. Trial and error. Hopefully minimal error.
I have a Minolta Hi-Matic G that I purchased recently and found the wire connected to the light meter has a corroded diode that is in readable. I can’t seem to find any information on what one I can use to replace it. Do you have any suggestions on what I can use to replace it or how to find out. I have pictures if you would need a visual guide.
Diode are fairly forgiving try determine the types of diodes behave differently, short of accessing another Hi-matic, trying a diode substitute should do no harm. A good forward-based silicon diode displays a voltage drop ranging from 0.5 to 0.8 volts for the most commonly used silicon diodes. Some germanium diodes have a voltage drop ranging from 0.2 to 0.3 volts. The ECG109 seems to consistently run a drop of 1.6 voltsThe multi-meter displays OL when a good diode is reverse-biased. The OL reading indicates the diode is functioning as an open switch. The multi-meter will give additional information about the diode. A bad (opened) diode does not allow current to flow in either direction. The multimeter will display OL in both directions when the diode is opened. A shorted diode has the same voltage drop reading (approximately 0.4 V) in both directions.If you have a multi-meter with a Diode Test mode you can determine the voltage drop of your diode before installation. The Diode Test mode produces a small voltage between test leads. The multi-meter then displays the voltage drop when the test leads are connected across a diode when forward-biased. The Diode Test procedure is conducted as follows:
If you are checking in circuit make certain no voltage exists at the diode. Voltage may be present in the circuit due to charged capacitors. Other wise, set your multi-meter to the Diode Test mode.It may share a space on the dial with another function. Connect the test leads to the diode. Record the measurement displayed. Reverse the test leads. Record the measurement. Compare results
Why not a resistor?
Well... a resistor resists current (amps) from flowing in a circuit. While it is doing this, a voltage will appear across the resistor. How much voltage appears across the resistor depends on what other thing are in the circuit resisting current to flow. So a resistance fundamentally decreases current not voltage.
What about combinations of more than 1 diode? This should open up a lot of possibilities. Or does it not work like that?
Thanks
Ok, my reading on this is that indeed combinations of diodes can indeed be used and work as I suggested, voltage drop is combined for two diodes in series. So a diode dropping voltage 0.1v with a seconded dropping voltage 0.1v would result in a total drop of 0.2v. That means 1.5v would go to 1.3v. Voila.
I realize there must be some reason this isn't done, but I want to know why. I sure would like to do this to all my cameras but it would be expensive using the Ecg109 diodes. A lot of diodes are just pennies.
Some electrical engineer needs to get on this.
This could absolutely be done if there were any 0.1V drop diodes, which as far as I'm aware either don't exist or might be even rarer than the ECG109
will IN34 shown in the video work?
or it's 1n34a? seems cheap on Ebay than ECG109
Should work. Will do no harm to try one.
Hi, what diod should i use for my canon ft ql? Im not Speak english and i dont understand nothing in this vídeo, please help
So I see the "M9" that is not actually the M9, and a few trying to look like it, but none that actually drop the voltage. The Canon EF I discovered has a voltage regulator. (Much to my delight at the time). Are there noteworthy cameras which also have a regulating circuit so that the alkaline 1.5 cell works? I just put in my order for both types. My challenge is the Canon (Bell & Howell) Dial 35. AKA Dial 35-2. Is this feasible I wonder? Been done?
It is feasible. Snug quarters, but doable. Such a cool camera.
Maybe you can help me with this one. I've got a Minolta Hi-Matic E Rangefinder (fully program mode) which requires two PX645 1.35v mercury batteries. I've used two 675 zinc air batteries but ran into several concerns. First, they don't last too long. Second, on this camera, when there is sufficient lighting the light in the viewfinder is green. When the lighting requires less then 1/30 SS, it starts green then turns red. With the 675 batteries, you'll never see the red light. I want to use 357/303 1.5v batteries but don't know how this will affect the exposure. I've read that it has a bridge circuit. Do I need a mod, or can I simply use 1.5v without issue? Thanks.
use 1.5v batteries and set the film speed slower than you are using. Example if you are using 200 iso film set the camera to 100 iso.
@@abbas1872 thanks. I ended up bridging two diodes in the battery compartment along with two 1.5v batteries. Worked great, until the camera kicked the bucket. RIP camera. 😢
Number One as usual!
Thank you.