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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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3rd Mar 2017, 11:31 am | #21 |
Dekatron
Join Date: Aug 2016
Location: Colchester, Essex, UK.
Posts: 4,081
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Re: Vintage Radio Solder Joints
I have also noticed in these older 'changed' solder joints that the change of state is slower than normal, it becomes like putty before it melts properly.
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3rd Mar 2017, 11:40 am | #22 | |
Rest in Peace
Join Date: Apr 2008
Location: London, UK.
Posts: 2,508
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Re: Vintage Radio Solder Joints
Quote:
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3rd Mar 2017, 5:59 pm | #23 |
Nonode
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,152
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Re: Vintage Radio Solder Joints
When I remove a faulty circuit board I immediately look at the soldered connections of board mounted transformers for that particular type of 'dry joint' which occurs after several years of use.
I am sure that the soldered joints were healthy when they left the factory. I am inclined to believe it is due to vibration. |
3rd Mar 2017, 6:04 pm | #24 |
Dekatron
Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,736
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Re: Vintage Radio Solder Joints
Maybe work-hardening induced by high-frequency mechanical vibration?
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Phil Optimist [n]: One who is not in possession of the full facts |
3rd Mar 2017, 10:44 pm | #25 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,346
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Re: Vintage Radio Solder Joints
I think this type of failure happens with the combination of high frequencies (line frequency sort of high) and high currents. No doubt this can also involve mechanical factors as Lucien suggests.
I used to buy, renovate and sell Grundig CTVs, those with the thyristor line output circuits. I don't think ANY set suffered as many (so called) "drys" as those. I used my Weller gun, getting thro tips and solder at a rapid rate, but after that the sets were reliable, and from my point of view, profitable. Les. |