[HBR] Negative temp compensation capacitors

[amargosaent at iscweb.com]

Has anyone on the reflector identified a source for negative temp 
coefficient capacitors in the N750 range available in small capacitance 
ranges (e.g., 1 pfd through 20 pfd in 1  and 2 pfd steps)?  I am aware 
of one US  manufacturer (Presidio Products) making a wide range of those 
components, but apparently only through contract with defense and 
aerospace manufacturers, nothing available (according to their local 
rep) through distributors or mail-order houses (Newark et al).

These caps are used in the HBR 11/13 Hartley oscillator design to 
stabilize frequency drift caused by temperature rise on start-up.

73 de W6HHT