The 11th edition, large format, blue cover, 1948 Radio Handbook (from
Editors and Engineers) shows several schematics and projects using the
70E8. None show 160 meter operation though the output from the
oscillator is on 160 meters. The dials (old and new style) don't show
160 meters as an option. Then I checked the bands list up in the front
of the handbook. No 160 meter operation was authorized. The lowed ham
frequency was 3.5 MHz. So the circuits didn't include 160 meters.
Most any buffer stage should work well, a 6AG7 might give a little
better isolation than a 6AK6 and be more appropriate being an octal
based metal tube like the oscillator tube.
One of the "projects" was the circuit of the 310C.
73, Jerry, K0CQ, Technical Advisor to the CRA.
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Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.