Temperature-compensated combiner

A temperature--compensated resonator for controlling a middle frequency for a radio frequency transmitting system, comprising:

• a cylindrical housing having an axially inner end, an axially outer end, and a peripheral sidewall extending in an axial direction from said outer end to said inner end;
• a control rod disposed within the housing and arranged to control a middle frequency depending on adjustment spatial positioning of the control rod in said axial direction;
• said control rod having an inner end facing the inner end of said housing;
• a resonator tube secured to the housing and coaxially disposed around the control rod;
• said resonator tube having an axially inner end facing the inner end of said housing;
• a regulating cup having an end wall and a peripheral side wall;
• said cup being disposed within the housing between the inner end of the housing and the inner end of the control rod, and being cupped about said inner end of the control rod between said inner end of said control rod and said inner end of said housing;
• said cup being coaxial with said control rod and said resonator tube;
• a motor disposed entirely within said resonator tube near said outer end of said housing and having a shaft connected to the control rod for adjusting spatial positioning of the control rod in said axial direction;
• said motor including a frame;
• a temperature-compensating structure for compensating for longitudinal expansion and contraction in said axial direction, of a unit comprised of said control rod, said resonator tube and said cup;
• said temperature-compensating structure including:
• a temperature-compensating tube arranged to move said control rod in said axial direction in response to changes in temperature;
• said temperature-compensating tube being positioned within said resonator tube and secured, at axially spaced sites thereon, to said inner end of said resonator tube and to said frame of said motor;
• and
• first and second telescopically coaxially related sleeves respectively made of different materials from one another, each having an axially inner end and an axially outer end;
• said first of said sleeves being disposed around said control rod and having said inner end thereof attached to said inner end of said control rod;
• and said second of said sleeves surrounding said first of said sleeves, having said inner end thereof attached to said cup, and having said outer end thereof attached to said outer end of said first sleeve.