01-18-2014, 01:15 AM
In relation to what Mike (Morzh) was speaking of the instability I am speaking of is unrelated to tin whiskers, tin whiskers cause shorted elements not intermittent ones. The transistor linked to was also a European made Phillips type, those obviously used tin plating in the cases, at least in that production of OC171s. As Mike suggested had they used a copper or some other plating, or mixed lead in with the tin plate, they would not have had this problem, it also has nothing to do with what material they chose for the elements.
I think that is the Soviet made Germanium transistors were made to military specs, which they most likely were, they likely would have used something other then tin plate in the cases. I think that the noise and intermittent problems with older transistors are due to a combination of age and early production methods, germanium transistors were largely phased out in new equipment by the late 60s here. Since the Soviet Union obviously stuck with germanium longer then they did in the West they likely would have refined out most of the bugs with experience.
Tin whiskers are not unique to early transistors though, much of that newer, "politically correct", lead free junk solder is notorious for forming tin whiskers, not to mention cracking and cold solder (dry) joints. In fact they are not allowed to use lead free solder in medical, aerospace, or military equipment, even in Europe, for those reasons. Tin plating will also create whiskers on a piece of sheet metal, often with no voltage potential across it at all: http://www.youtube.com/watch?v=apnlJJ0t_LY
He says he has even found tin whiskers like this in NOS TVs, new in the box.
Whatever the cause, the problem is the same, if you have a defective transistor you will need to find some form of substitute.
P.S I think that a lot of the shipping costs are baloney, like for example it costs at least 30% more to ship something from Australia to New Zealand then it does from New Zealand to Australia, why? Both are out in the South Pacific, similar culturally, similar standards of living, it just illustrates how arbitrary a lot of postal rates are.
Regards
Arran
I think that is the Soviet made Germanium transistors were made to military specs, which they most likely were, they likely would have used something other then tin plate in the cases. I think that the noise and intermittent problems with older transistors are due to a combination of age and early production methods, germanium transistors were largely phased out in new equipment by the late 60s here. Since the Soviet Union obviously stuck with germanium longer then they did in the West they likely would have refined out most of the bugs with experience.
Tin whiskers are not unique to early transistors though, much of that newer, "politically correct", lead free junk solder is notorious for forming tin whiskers, not to mention cracking and cold solder (dry) joints. In fact they are not allowed to use lead free solder in medical, aerospace, or military equipment, even in Europe, for those reasons. Tin plating will also create whiskers on a piece of sheet metal, often with no voltage potential across it at all: http://www.youtube.com/watch?v=apnlJJ0t_LY
He says he has even found tin whiskers like this in NOS TVs, new in the box.
Whatever the cause, the problem is the same, if you have a defective transistor you will need to find some form of substitute.
P.S I think that a lot of the shipping costs are baloney, like for example it costs at least 30% more to ship something from Australia to New Zealand then it does from New Zealand to Australia, why? Both are out in the South Pacific, similar culturally, similar standards of living, it just illustrates how arbitrary a lot of postal rates are.
Regards
Arran
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