[Collins] Question about a 70E-11 PTO

[Dr. Gerald N. Johnson, electrical engineer]

I have a sheet from Collins Oscillator Test Department, Les Fuhrman,
dated Jan 11, 1960.

It says the 70E-11, part number 503 9558-003 was used in the 708-A.
Filament was 6.3 volts, B+ 250. No oven. Tuned 1.0 to 1.5 MHz over 10
turns. Pin 2 should have 45 pf to ground and pin 4 should have 20 pf to
ground and will give 15 to 30 volts. The 708-A also used the 70E-10 that
tuned 600 to 800 KHz.

Another list I have showing coil assembly part numbers shows it has the
same coil, slug, and lead screw as the 70E-1 used in the ARC/2. Uses the
same coil form as the 70E8A, 79E8B, and the same purchased slug as the
70E-2, 70E-7, 70E-10, and 70E21. 

Those PTO used in 51J, 75A4, R390 and R390A (for BFO) that had no tubes
are marked tank only, which hints that maybe there were subminiature
tubes inside the 70E-11. The line for the 70E-11 doesn't say tank only.

73, Jerry, K0CQ, Technical Advisor to the CRA
-- 
Entire content copyright Dr. Gerald N. Johnson, electrical engineer.
Reproduction by permission only.