| Class Number |
Class Name |
Patents |
| 330/10 |
Modulator-demodulator-type amplifier |
727 |
| 330/11 |
With d.c. reinsertion circuit |
40 |
| 330/113 |
Polyphase power supply (i.e., for an electrode, cathode heater, or filament) |
1 |
| 330/114 |
Unrectified a.c. power supply for an electrode (i.e., not the heater) |
0 |
| 330/116 |
With balanced-to-unbalanced coupling |
9 |
| 330/117 |
With unbalanced-to-balanced coupling |
9 |
| 330/118 |
Including a push-pull stage |
22 |
| 330/124R |
With plural amplifier channels (e.g., parallel amplifier channels) |
623 |
| 330/127 |
With control of power supply or bias voltage |
129 |
| 330/143 |
Thermally responsive impedance |
18 |
| 330/144 |
Variable impedance for signal channel controlled by separate control path |
113 |
| 330/146 |
Wheatstone bridge with amplifier in at least one arm |
121 |
| 330/147 |
Plural signal inputs |
44 |
| 330/148 |
Plural signal outputs |
35 |
| 330/149 |
Hum or noise or distortion bucking introduced into signal channel |
1,167 |
| 330/150 |
Cascaded similar amplifying device of different characteristics |
31 |
| 330/151 |
With amplifier bypass means (e.g., forward feed) |
517 |
| 330/152 |
Cascaded differently coupled between stages |
2 |
| 330/155 |
Unicontrol of coupling or the circuits associated therewith |
4 |
| 330/156 |
Bootstrap coupling |
38 |
| 330/157 |
Interstage coupling |
4 |
| 330/185 |
Input networks |
3 |
| 330/192 |
Output networks |
5 |
| 330/199 |
With power or bias voltage supply |
32 |
| 330/1R |
With diverse-type art device |
8 |
| 330/2 |
With amplifier condition indicating or testing means |
255 |
| 330/207R |
Miscellaneous |
14 |
| 330/250 |
With semiconductor amplifying device (e.g., transistor) |
44 |
| 330/3 |
With plural diverse-type amplifying devices |
28 |
| 330/4 |
With maser-type amplifying device |
24 |
| 330/4.5 |
Parametric amplifiers |
35 |
| 330/41 |
With gas or vapor tube amplifying device |
5 |
| 330/42 |
With secondary electron emission tube amplifying device |
12 |
| 330/43 |
With traveling wave-type tube |
97 |
| 330/44 |
With electron beam tube amplifying device |
32 |
| 330/47 |
With magnetically influenced discharge device (e.g., magnetrons) |
12 |
| 330/49 |
With vacuum tube having distributed parameter impedance characteristics |
6 |
| 330/5 |
With solid element wave propagating amplifying device |
22 |
| 330/50 |
With dummy tube |
2 |
| 330/51 |
Combined with automatic amplifier disabling switch means |
723 |
| 330/52 |
With pilot frequency control means |
144 |
| 330/53 |
With distributed parameter-type coupling means |
142 |
| 330/58 |
With rotating dynamoelectric amplifying device |
1 |
| 330/59 |
Having light-controlled or activated device (i.e., not light signal) |
196 |
| 330/6 |
With hall effect type means |
19 |
| 330/60 |
Having magnetostrictive-type amplifying device |
3 |
| 330/61R |
With resistive-type amplifying device |
10 |
| 330/63 |
With magnetic means amplifying device |
5 |
| 330/64 |
With space charge grid tube |
1 |
| 330/65 |
Involving structure other than that of transformers per se |
32 |
| 330/69 |
Sum and difference amplifiers |
349 |
| 330/7 |
With capacitive amplifying device |
5 |
| 330/70 |
Anode energized through discharge path of controlled vacuum tube |
6 |
| 330/75 |
Signal feedback |
35 |
| 330/8 |
With saturable reactor-type amplifying device |
19 |
| 330/9 |
With periodic switching input-output (e.g., for drift correction) |
643 |
