K-capture to positron branching ratios were measured in the decay of Na/ sup 22/, Co/sup 58/, and Ga/sup 68/ -- all pure Gamow-Teller emitters, using coincidence scintillation spectrometer techniques. The measured values are 0.105 plus or minus 0.004 for Na/sup 22/, 5.08 plus or minus 0.17 for Co/sup 58/, and 1.28 plus or minus 0.12 and 0.10 plus or minus 0.02 for Ga/sup 58/. From these the Fierz interference terra is computed to be b =--0.004 plus or minus 0.012, -0.004 plus or minus 0.14, --0-03 plus or minus 0.02, and +0.03 plus or minus 0.01, respectively. These results indicate that the Fierz interference in Gamow-Teller interaction is very small. The decay of 270 day Ge/sup 68/ was investigated in equilibrium with Ga/sup 68/ to look for a possible low-lying 0+ level in Ga/sup 68/ using x-ray--x-ray and x-ray- gamma -ray coincidences. The result was negative. Besides the 9 kev K x ray, the 1.07 Mev gamma ray in the decay of Ga/sup 68/ and annihilation radiation, no other gamma rays were detected (<8% of 1.07 Mev gamma ray). The number of positrons per 1.07 Mev gamma - quantum was determined as 19.47 plus or minus 2.10. The ratio of …