NOS/NIB quad of Siemens Germany E188CC/7308 tubes. I just tried these out and prefer my Amperex tube set so I'm turning these. Using 1bionicear's data:
Tubes have matching G6 8B date codes identifying them as early 1970's production. Tubes have the signature 4 seams on top, small halo getters, and gold pins.
Tubes were tested on a TV10D/U military tube tester.
Tube #1 12800 [micromhos] / 13000 [micromhos]
Tube #2 12600 [micromhos] / 13000 [micromhos]
Tube #3 13200 [micromhos] / 13400 [micromhos]
Tube #4 13000 [micromhos] / 13100 [micromhos]
Minimum good value on TV10D/U is 6750 [micromhos]
Maximum value on TV10D/U is 15000 [micromhos]
Tubes were also tested on a Sencore TC-162 emissions tester. All four tubes tested 106 / 106 on a scale where 70 is the minimum good rating.
