GROUND RADIO BULLETIN NO. 43 - OCTOBER 14, 1952 COMMS. DEPT. L.A.D.
4-250A TUBES
There have been several instances where filament failure with this tube has been found to be remediable. The trouble symptoms are overheating of the filament pins on the tube base until the solder melts and drops from the pins. This is undoubtedly caused by a manufacturing defect which results in a poor contact within the pin and resistance thus introduced develops abnormal heat, and eventual melting of solder and then an open circuit. When this is encountered, remove the tube from the transmitter and heat both filament pins with a soldering iron and apply new solder. Heat the pins well, and see that the solder runs down into the pin. Use soldering paste to assist in creating a good^connection. It has been found that the tube can be restored to normal cpndition with this treatment, providing the trouble is actually in the tube iiiament pm. Also, before returning the tube to the transmitter, examine the socket carefully for good spring contact with the tube pins, and for any discoloration from overheating. Maurice Duchatellier - OIC, PAP first reported this salvage operation. Thanks MD.
EQUIPMENT SHIPPING CASES
Receivers and Auto Keys are sent to line stations in specially constructed shipping boxes to assure that these units arrive in good condition. Please do all possible to turn these boxes around and ship back to Miami as soon as possible. If equipment is to be returned in them for overhaul, make the equipment exchange promptly. If the boxes are to be returned empty, do not let them stay around the station idle* These packing boxes are expensive to construct, and not having them back promptly results in some other station having to wait for needed overhauled equipment.
FORM 9211—2107
