Germanium switching transistor

[swolf]

I just ran across a catalog that lists an Antique transistor that can be used to replace the switching transistor in Kundo , ATO clocks and any battery clock that uses a germanium transistor to switch the electromagnet on and off.

Go to: www.goldmine-elec.com In the search box on the home page type in part #G2299. When the item shows up click on the transistor and you get the full description of the transistor

The price is $1.00 ea. which is a bargain except the minimum order is $10. Hey, you will never find new ones again so stock up.

Sherm

 

[swolf]

I just ran across a catalog that lists an Antique transistor that can be used to replace the switching transistor in Kundo , ATO clocks and any battery clock that uses a germanium transistor to switch the electromagnet on and off.

Go to: www.goldmine-elec.com In the search box on the home page type in part #G2299. When the item shows up click on the transistor and you get the full description of the transistor

The price is $1.00 ea. which is a bargain except the minimum order is $10. Hey, you will never find new ones again so stock up.

Sherm

 

[Mike Phelan]

Beware of NOS germanium devices with metal cases - they grow whiskers of tin inside them! Even when not in use.

 

[charles e]

I have heard of the lads at the British Vintage wireless Society fixing AF series transistors with shorts by charging up a capacitor, hooking up one side to the three leads ( joined together ) and the touching the other capacitor lead to the case. This spark apparently vaporises the whisker and you have a good transistor again. Paul Stenning at BVWS writes extensively about electronic tricks and appears to have forgotten more about electronics than I will ever know, so look him up on the web. God luck

 

[DC Kelley]

whiskers

The transistor you refer to, a 2N128 JAN in an odd metal can, can readily be found in common modern plastic packages that will not have the "whiskers" problem. Technically this is called a TO-92 package, but any modern package will do fine. I can not say anything positive about trying to zap the whiskers off a part this way other then it is a text book way to cause failure in the part soon thereafter.

I think that any desire to use this outdated packaging is pure nostalgia without any technical value (perhaps there is some slight value in an more"exact" replacement to a collector). Plus, it appear to me that Kundo at least abandoned this packaging as soon as alternatives were available. Here is a shot of the underside of a Kundo unit, where you can see the small circuit board. Note that they are using two plastic package transistors here. As you can see,

http://serv4.itsware.net/bb/download.php?id=778

I am afraid I do not know the sequence of years of the different models of these (anyone have a reference text on this subject?) but these very early medal transistors where superceded by another simple "pot" type (which enjoyed military use for some time) and then the mass produced plastic style that persisted for two decades until the advent of cheap surface mount things.