Matched quad 6p3s. The pictures are actual. Made in 60s. One pair or more.
Quality tubes for military equipment. High-quality tubes have thick gold-plated grids.
Tested with L3-3 tubetester at Ua=250V, Ug2=250V, Ug=-14V Uf=6.3V DC
Results:
1p
1t. 68uA ; S=5.7uA/V feb 1966
2t. 67 5.7 feb 1966
2p
1t. 74uA ; S=5.9uA/V sep 1970
2t. 74 6.1 sep 1970
3p
1t. 73uA ; S=6uA/V jul 1964
2t. 74 6 jul 1964
4p
1t. 73uA ; S=6uA/V feb 1965
2t. 74 6 feb 1965
storage code: bta d41