Hi,
It was commonly known that tubes were made by one manufacturer and sold by another.
In order to identify which company ACTUALLY made the tube, the ACTUAL manufacturer's EIA code number would be stamped somewhere on the tube. Manufacturers would commonly make tubes for other companies.
If Eimac really made the tube, the code # 162 should appear on the tube somewhere.
As I recall, Machlett and GE appeared to make most of the 2C39/7289 family, so I would not be surprised to see Eimac tubes that were really made by Machlett or GE.
Do you see one of the following numbers stamped on your 7289s ?
Just for your information (FYI).
73,
Jerry W7QX
Tubes and CRT's EIA code
Amperex (USA) 111
Bendix 125
DuMont 158
Eimac (Eitel-McCullough, Inc) 162
Electronic Tube Corp 169
General Electric Co (USA) 188
Hytron (CBS-Hytron) 210
Machlett 231
RCA (Radio Corp of America) 274
Raytheon 280
Superior Tube Co 310
Sylvania (Hygrade Sylvania Corp) 312
Tung-Sol 322
United Electronics 323
Western Electric 336
Westinghouse 337
Zenith Radio Corp (CRT's) 343
Nortn American Philips Corp 423
Taylor (aka Cetron-Taylor) 713
Lewis & Kaufman 738
National Electronics (also Cetron) 749
Penta Laboratories 771
Vacuum Tube Products 781
Varian Associates 809
Litton Industries 879
Electrons, Inc 935