Discussion on "Thermal-Frequency-Drift Compensation" (by T.R.W. Bushby) [with author\´s reply]

The design of military communication equipment must consider, among other factors, the effect of varying temperature on the equipment. The commentor feels that Mr. Bushby´s article, although very opportune, omits the discussion of a very basic point to his whole article on page 548 where the premise of finding the smallest average drift factor θ over the frequency range is assumed. This criterion is not the most desirable condition. In replying, Mr. Bushby shows that the condition for minimum average drift factor (/θ/) throughout the range can be demonstrated geometrically.