08-09-2008, 01:30 AM
...glad you bent those tube pins for good connection! I forgot to mention that! The best way to "clean" the tube pins on loctal tubes, is by actually hand-scraping each individual pin with a exacto-knife blade till "shiny".
Most usually, wire brushes, emory cloth, dont have enough cleaning power when dealing with those type tubes! It takes "force" to get those pins clean(scraping) again for proper contact with the loctal-sockets! It is also a good idea to spray WD-40 on both the tube pin tips , and sockets to keep the loctals-connections (all) from corroding again in the near future, or they will in high-humidity type climates! You bet, bad tube design invention from the get-go,period!!
Anytime you have a prob with any radio using loctal-type tubes after full re-cap, most usually, the residual probs of alignment or etc, can be traced back to the loctal tube design!
Ive been told by several WW2 USAF radio-techs, that the loctal-type tubes were originally designed by "JAN" ( IE: joint Army/NAVY) to be used in the WW2 era aircraft Radar systems,etc, and lots of them failed at very in-opportune times of warfare!! Im sure lots of Radio mfgrs of that era snapped the leftover JAN type loctal type tubes up to be used in "receivers" only for a very modest/ quantity price back in those days to be used in home type radio receivers! Zenith also used lots of the loctal type Govt leftovers in their production runs of tube radios also, as well as most other mfgrs! Now, all us vintage radio techs get to deal with them!!
Most usually, wire brushes, emory cloth, dont have enough cleaning power when dealing with those type tubes! It takes "force" to get those pins clean(scraping) again for proper contact with the loctal-sockets! It is also a good idea to spray WD-40 on both the tube pin tips , and sockets to keep the loctals-connections (all) from corroding again in the near future, or they will in high-humidity type climates! You bet, bad tube design invention from the get-go,period!!
Anytime you have a prob with any radio using loctal-type tubes after full re-cap, most usually, the residual probs of alignment or etc, can be traced back to the loctal tube design!
Ive been told by several WW2 USAF radio-techs, that the loctal-type tubes were originally designed by "JAN" ( IE: joint Army/NAVY) to be used in the WW2 era aircraft Radar systems,etc, and lots of them failed at very in-opportune times of warfare!! Im sure lots of Radio mfgrs of that era snapped the leftover JAN type loctal type tubes up to be used in "receivers" only for a very modest/ quantity price back in those days to be used in home type radio receivers! Zenith also used lots of the loctal type Govt leftovers in their production runs of tube radios also, as well as most other mfgrs! Now, all us vintage radio techs get to deal with them!!
