UHF tuner having frequency setting fine toned by varying characteristic impedance of resonant line

Claim 1

A radio frequency tuner for an extremely high frequency range said tuner comprising: a. a grounded casing; b. a rough tuning portion including a variable capacitor for tuning to one of a plurality of frequencies in a predetermined band, said capacitor including a fixed element and a movable element which rotates about an axis; c. a fine tuning portion for the fine adjustment of the one of the plurality of frequencies to which said rough tuning portion is tuned, said find tuning portion comprising a distributed constant line including a resonant line having one end connected to said fixed element of said variable capacitor and the other end connected to said casing; d. a conductor element movably disposed adjacent to said resonant line for selectively being driven toward and away from said resonant line to thereby vary the characteristic impedance of said distributed constant line to thereby finely adjust the tuned frequency; e. a first rotary shaft means connected to said movable element and rotatably carried by said housing for adjusting the position of said movable element relative to said fixed element to thereby vary the capacitance of said variable capacitor; f. a second rotary shaft means coaxially and rotatably provided on said first rotary shaft means; g. moving means operably coupled to said second rotary shaft means for moving said conductor element with respect to said resonant line upon the rotation of said second shaft means to thereby finely adjust the position of said conductor element.