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Class Number: 455 Class Title: TELECOMMUNICATIONS Subclass Subclass Number Title 1 INTERFERENCE SIGNAL TRANSMISSION (E.G., JAMMING) 2 AUDIENCE SURVEY AND USE ACCOUNTING 3.1 DISTRIBUTION SYSTEM (E.G., PLURAL CABLES, ETC.) 3.2 .Receiver for satellite broadcast 3.3 .Combined with power distribution network 4.1 .Remote control of distribution 4.2 ..With subscriber selection or switching 5.1 .Two-way 6.1 .Common antenna or cable 6.2 ..With specific cable converter 6.3 .Combined with diverse type art device (e.g., audio/sound or entertainment systems, etc.) 7 CARRIER WAVE REPEATER OR RELAY SYSTEM (I.E., RETRANSMISSION OF SAME INFORMATION) 8 .Failure compensation (e.g., spare channel) 9 .Monitoring 10 ..Fading compensation 11.1 .Portable or mobile repeater 12.1 ..Space satellite 13.1 ...With plural repeater or relay systems 13.2 ...With synchronizing of satellites or system 13.3 ...With antenna feed network or multiple antenna switching 13.4 ...Power control 14 .With transmission line 15 .Two separate way transmission 16 ..Simultaneous using plural repeaters at each location 17 .Plural modulated carriers 18 .With delay or recording 19 .Common antenna 20 .With frequency conversion 21 ..With demodulator 22 ..Plural conversion stages 23 .Frequency or phase modulation 24 .Transmitter/receiver feedback compensation 25 .Directive antenna 26.1 USE OR ACCESS BLOCKING (E.G., LOCKING SWITCH) 31.1 SYSTEM WITH RECEIVER SELECTION 32.1 .Receiver scans for address signal 33.1 .Zoned or cellular 33.2 ..Hand-off control 33.3 ...Using plural antennas 33.4 ..With overlapping zones 34.1 .Exclusive assigned channel 34.2 .Seized channel 35.1 .Tone coded squelch 36.1 ..Plural tones 37.1 ...Difference frequency 38.1 .Coded sequence 38.2 ..With actuation (e.g., turn on/off or alarm indication, etc.) 38.3 ...Power control or battery saving 38.4 ...Visual indicationn 38.5 ...Tone sequence 39 TRANSMITTER AND RECEIVER AT SEPARATE STATIONS 40 .Earth or water medium 41 .Near field (e.g., inductive or capacitive coupling) 42 .Frequency or phase modulation 43 ..With modification of frequencies of analog signal passed (e.g., pre-emphasis and de-emphasis) 44 ..With stated modulation index 45 ..Via subcarrier 46 .Suppressed carrier wave system 47 .Single or vestigial sideband system 48 .Inverted sideband 49.1 .Plural transmitters or receivers (i.e., more than two stations) 50.1 ..Noise, distortion, or singing reduction 51.1 ...Synchronized stations 51.2 ....Simulcast system 52.1 ...Fading compensation 52.2 ....Due to weather attenuation 52.3 ....Rayleigh or multipath fading 53.1 ..With central station (e.g., master, etc.) 54.1 ...To or from mobile station 54.2 ....With service request and response 55.1 ....Using radiating transmission line 56.1 ....Multiple base stations 57.1 ...Plural receivers tuned to common frequency 58.1 ..Break-in or priority override 58.2 ..Lockout or busy-idle signalling 59 .Single message via plural carrier wave transmission 60 ..Different phases of same frequency carrier 61 .Single message via plural modulation of single carrier 62 .Optimum frequency selection 63 .Distortion, noise, or other interference prevention, reduction, or compensation 64 ..Plasma source or barrier 65 ..Anti-multipath 66 .With diverse art device 67.1 .With measuring, testing, or monitoring of system or part 67.2 ..Using a chamber (e.g., room testing or audio surveillance, etc.) 67.3 ..Noise, distortion or unwanted signal detection (e.g., quality control, etc.) 67.4 ..Using a test signal 67.5 ..Of a microwave link or system 67.6 ..Phase measuring (e.g., group delay, propagation effects, etc.) 67.7 ..With indication (e.g., visual or voice signalling, etc.) 68 .With control signal 69 ..Transmitter controlled by signal feedback from receiver 70 ..Receiver control signal originates at message transmitter 71 ...Frequency control 72 ...For compression and expansion of message signal (i.e., companding) 73 TRANSMITTER AND RECEIVER AT SAME STATION (E.G., TRANSCEIVER) 74 .Convertible (e.g., to diverse art device) 75 .With frequency stabilization (e.g., automatic frequency control) 76 ..Synthesizerr 77 .With tuning 78 .With transmitter-receiver switching or interaction prevention 79 ..Automatic (e.g., voice operated) 80 ...With distributed parameter coupling 81 ....Waveguide 82 ...Common antenna 83 ..Single antenna switched between transmitter and receiver 84 .With a common signal processing stage 85 ..Transmitter oscillator used as detector 86 ..Transmitter oscillator used as local oscillator 87 ...Tunable or variable 88 .Transceiver controlling a separate transceiver or receiver 89 .Portable or mobile 90 .Housing or support 91 TRANSMITTER 92 .Remote control of a transmitter 93 .Convertible to different type (e.g., AM to FM) 94 .Alternator 95 .Mobile or portable 96 ..Transmitter ejected from moving vehicle 97 ..With antenna ejection or external support 98 ..With aircraft, satellite, or projectile 99 ..With vehicle 100 ..Body attached or connected 101 .Diversity 102 .Plural modulation 103 .Plural separate transmitters or channels 104 ..Carrier and sidebands separately transmitted 105 ..Common frequency 106 .Modulation by absorption, shielding, or reflecting 107 .With variation of antenna impedance or dimension for modulation 108 .Amplitude modulation 109 ..Vestigial or single sideband or suppressed carrier 110 .Angle modulation 111 ..Including distributed parameter structure 112 ..With frequency multiplication or division 113 ..With frequency control 114 .With harmonic radiation suppression 115 .Measuring, testing, or monitoring of transmitter 116 .Carrier amplitude control (e.g., voice operated on/off) 117 .With electrical protection of transmitter circuit or operator 118 .Frequency conversion 119 .Carrier frequency stabilization 120 .Including tuning 121 ..In antenna circuit 122 ...With saturable reactor 123 ...Automatically controlled 124 ..Distributed parameter device 125 ..Automatic adjustment of tuning 126 .With feedback of modulated output signal 127 .Power or bias voltage supply 128 .With casing or housing 129 .With coupled antenna 130 RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER 131 .Frequency conversion between signal source (e.g., wave collector) and receiver 132 .Plural receiverss 133 ..With output selecting 134 ...By signal strength 135 ...By signal quality (e.g., signal to noise ratio) 136 ...With control (e.g., automatic gain control, automatic frequency control, etc.) 137 ..With output combining 138 ...With control (e.g., automatic gain control) 139 ....Frequency or phase control 140 ..Selectively actuated or controlled 141 ..Including common stage (e.g., local oscillator) 142 .Convertible to different type (e.g., AM to FM) 143 ..With distinct signal path for each type 144 ..With dual purpose amplifying or other stage 145 .Panoramic display 146 ..Plural separate paths or plural oscillators 147 ..Particular local oscillator control 148 ..With oscilloscope sweep signal derivation or control 149 .Plural output (e.g., plural speakers ) (not stereo) 150.1 .Signal selection based on frequency (e.g., tuning) 151.1 ..Remote control of channel or station selection 151.2 ...Wireless link (sonic, RF or infrared) 151.3 ...Remote oscillator tuned 151.4 ...Plural electronic devices controlled 152.1 ...Of or combined with vehicle receiver 153.1 ...Mechanical 153.2 ....With wired link 154.1 ..With indication of frequency, channel, or selector condition (e.g., tuning aid) 154.2 ...Scanning display 155.1 ...By meter 156.1 ...Audible indicator 157.1 ...Analog frequency indication (e.g., dial) 157.2 ....With light indication or bar type 158.1 ...Channel index indication 158.2 ....With electronic digital indication 158.3 .....Using a counter 158.4 ....With multiple display functions 158.5 ....Non-numeric display (e.g., call letters) 159.1 ...Variable light indication 159.2 ....Plural lamps 160.1 ..Plural tuning modes (e.g., manual and scanning, etc.) 161.1 ..Frequency scanning 161.2 ...With processor control 161.3 ...Using signal strength or quality 162.1 ...Motor activated 163.1 ....Reversible motor (e.g., end-stop control) 164.1 ...With automatic frequency control 164.2 ....Processor controlled (AFC) 165.1 ...With frequency synthesizer 166.1 ...With channel skipping selection 166.2 ....With priority channel selection 167.1 ...With dual sweeping 168.1 ...Multiband 169.1 ...With particular variable voltage or current tuning 169.2 ....With varactor diode 170.1 ..With mechanical or electromechanical selection 171.1 ...Time actuated 172.1 ....Including a motorr 173.1 ...With automatic frequency control of fine tuning 174.1 ...With muting (e.g., silent tuning) 175.1 ...With carrier wave preset 176.1 ...Combined with band selection 177.1 ...Combined with other control (e.g., bandwidth, volume, gain, etc.) 178.1 ...With plurality of tunable circuits 179.1 ..Channel or station selection 180.1 ...Combined with band selection 180.2 ....UHF and VHF 180.3 .....With phase locked loop (PLL) tuning 180.4 .....Varactor tuned (e.g., varactor diode) 181.1 ...Time controlled 182.1 ...With frequency control 182.2 ....Automatic (AFC) 182.3 ...Fine tuning 183.1 ...With frequency synthesizer 183.2 ....Processor controlled 184.1 ...With comparing desired and existing tuning conditions 185.1 ...With channel information storage 186.1 ....With memory control or programming 186.2 .....Having a keyboard 187.1 ...Separate tuned circuits for each channel or station 188.1 ..Band selection 188.2 ...UHF and VHF 189.1 ...With plural separate mixer or converter circuits 190.1 ...With frequency conversion 191.1 ...With plurality of tuned circuits 191.2 ....Varactor tuned 191.3 ....With switching between stages 192.1 ..With frequency control 192.2 ...Automatic (AFC) 192.3 ...Fine tuning 193.1 ..With antenna circuit tuning 193.2 ...With plural resonant circuits 193.3 ...Including varactor diode 194.1 ..With muting (e.g., silent tuning) 194.2 ...Amplifier controlled 195.1 ..Variable voltage or current tuning 196.1 ..Including variation of local oscillator frequency 197.1 ...By simultaneous control with signal selection 197.2 ....Variable capacitor tuned 197.3 .....Including additional tuning circuit 198.1 ....Including distributed parameter control device 199.1 ....Discrete frequency types (e.g., channel switching) 200.1 ..With other control (e.g., volume, gain, bandwidth, etc.) 201 .Exalted carrier 202 .Suppressed carrier 203 .Carrier and single sideband 204 .Vestigial sideband 205 .Frequency or phase modulation 206 ..Responsive to one of overlapping signals 207 ..With plural conversion 208 ..With synchronized or controlled local oscillator 209 ...Plural local oscillators or mixers 210 ..With carrier amplitude modulation elimination (e.g., specified limiter) 211 ...Combined with other functionn 212 ..With squelch or other audio output silencing 213 ...Using specified filter 214 ..With particular discriminator or detector 215 ...Superregenerative 216 ..With particular frequency division or multiplication 217 .With protection circuit for receiver circuit 218 .Squelch 219 ..With automatic gain or volume control 220 ..Adjustable 221 ..Audio responsive 222 ..Noise controlled 223 ...Short duration (noise blankers) 224 ....Separate broadband detector channel 225 ..Plural paths 226.1 .Measuring or testing of receiver 226.2 ..Signal strength 226.3 ..Signal-to-noise ratio 226.4 ..With meter or indicator 227 .Responsive to an input signal of particular predetermined frequency 228 ..Responsive to specified modulation (e.g., call alarm, Conelrad) 229 ..Responsive to carrier absence or presence 230 .Local control of receiver operation 231 ..Applied at or for specific intervals or periods of time 232.1 ..Gain control 233.1 ...With diverse control (tone, etc.) 234.1 ...Automatic 234.2 ....Processor controlled 235.1 ....Forward acting 236.1 ....Variable conversion efficiency (variable oscillator amplitude, etc.) 237.1 ....Responsive to locally injected pilot 238.1 ....Responsive to vehicle speed 239.1 ....Nonlinear automatic gain control 240.1 .....Variable automatic gain control loop gain 241.1 .....Different gain stages 242.1 .....Delayed 242.2 ......Different delay for different signal stages or thresholds 243.1 ......Radio frequency stage only delayed 244.1 .....Dual time constant 245.1 ....Automatic gain control signal derived from information signal 245.2 .....Plural stages controlled 246.1 ....Responsive to plural inputs 247.1 .....Separate automatic gain control signals 248.1 ....Constant or controlled input impedance 249.1 ....Variable attenuator type 250.1 ....Automatic gain control to improve strong signal handling 251.1 ....Plural stages with different levels or bias to each stage (e.g., partial automatic gain control) 252.1 ....Semicondutor 253.1 ....Plural stages controlled with plates, screen grids, or cathodes connected in parallel 253.2 ....Plural amplifier stages 254 ..Sensitivity controll 255 ..Local oscillator frequency control 256 ...Combined with other control 257 ...Automatic 258 ....Utilizing particular local oscillator control 259 .....Reference oscillator or source 260 ......Phase lock loop or frequency synthesizer 261 .....Variable reactance (e.g., reactance tube) 262 ......Voltage controlled capacitor 263 .....Discriminator or detector 264 .....Voltage control of oscillator 265 ....With local oscillator synchronization or locking 266 ..Selectivity or bandwidth control 267 ..Tone control 268 ..Fidelity control 269 .With wave collector (e.g., antenna) 270 ..Power-line or receiver element used as wave collector 271 ..Suppression of radiation from receiver via wave collector 272 ..Plural separate collectors 273 ...With paticular output combining 274 ....Loop or coil antenna 275 ...With frequency changing or selecting in the output path of one or more collectors 276.1 ...With phase shifting, correcting, or regulating in the output path of one or more collectors 277.1 ...Selectively or alternately connected to receiver 277.2 ....By signal quality (e.g., noise) 278.1 ...Combined with noise or interference elimination 279.1 ....Plural antenna currents entering single transformer 280 ..With coupling to a stage of the receiver 281 ...Having distributed parameters 282 ....Transmission line 283 ...Undesired signal or noise control (e.g., antistatic) 284 ....Balancing or cancelling 285 ....With image frequency suppression 286 ....Wave filter, coil, or wave trap 287 ....Shunt or bypass 288 ....Particular composition (e.g., of cell or element) 289 ...With coupling varying, regulating, or control 290 ...Including passive tuned circuit 291 ...Using active device (e.g., as preamplifier or reactance) 292 ...Transformer or other passive inductance 293 ...Specified stage (e.g., mixer, amplifier, or demodulator) 294 ....With particular electron tube structure 295 .Modulation distortion or cross talk correction or elimination 296 .Noise or interference elimination 297 ..In vehicle 298 ..Originating in power supply 299 ...Filter or rectification in power supply energized by fluctuating or a.c. source 300 ..By shielding 301 ...Plural or compartmented shielding structure 302 ..Image frequency suppression 303 ..Using plural separate signal paths 304 ...Phase shift in at least one path 305 ...With balancing or neutralizing 306 ....Filter in at least one path 307 ..With specific filter structure 308 ..With amplitude limiterr 309 ...In demodulator or low frequency (audio amplifier circuit) 310 ..Internally generated noise or oscillations 311 ..In radio frequency amplifier, intermediate frequency amplifier or converter circuit 312 ..In demodulator or low frequency (e.g., audio frequency) 313 .Frequency modifying or conversion 314 ..Plural separate successive conversions 315 ...With plural separate local oscillators 316 ....With frequency stabilization for at least one local oscillator 317 ..Unwanted oscillation or radiation prevention 318 ..With specified local oscillator structure or coupling 319 ...With particular coupling 320 ....Lumped impedance 321 ...In a single envelope or with common active element (e.g., autodyne) 322 ....Plural common electrode 323 ..Particular frequency conversion structure or circuitry 324 ...Homodyne (i.e., zero beat or synchrodyne reception) 325 ...Including distributed electrical parameter structure 326 ....With balanced mixer 327 .....Stripline 328 .....Hollow waveguide 329 ....Electron beam tube 330 ....With nonlinear impedance (e.g., diode) 331 ...Crystal or electron tube diode 332 ...Push-pull 333 ...Transistor or integrated circuit 334 .With particular receiver circuit 335 ..Plural diverse function tube or stage (performs plural functions alternately or concurrently) 336 ..Superregenerative detector or discriminator 337 ..Discriminator or demodulator 338 ..Coupling or decoupling between stages 339 ...Band pass filter 340 ...Variably tunable or adjustable 341 ..Amplifier 342 ...Reflex type 343 ..With particular power or bias supply (includes battery saving means and includes self-powered) 344 .Combined with diverse art device 345 ..With vehicle 346 ...Detachable for portability 347 .Cabinet, housing, or chassis structure 348 ..With retractable or readily detachable chassis 349 ..Sectional or interconnectable (e.g., modules) 350 ..With particular speaker mounting 351 ..Transportable 352 .Remote control of receiver 353 ..Plural conditions from remote station 354 ...Mechanical 355 ..Amplitude, volume, or gain control 899 MISCELLANEOUS