US1668231A - Radio receiving apparatus - Google Patents

Description

May l, 1928.

E. E. CLEMENT ET AL RADIO RECEIVING APPARATUS Filed July 8. 1924 Patented May 1, 1928.

UNITED STATES NParr-:NT orrlcs.

EDWARD E. CLEMENT HARRY E. LOWIEINSTEIN-y OF WASHINGTON, DISTRICT Ol' COLUMBIA, ASSIGNOBS TO EDWARD F. COLLADAY,

COLUMBIA.

0F WASHINGTON, DISTRICT 0F RADIO l2R11?.CIEIVINGt APPARATUS.

Appucanm med July 3,1924. serial no. 724,886.

van improvement over that described and,

claimed in Letters Patent No. 1,522,308, granted to us January 6, 1925.

In said patented system we provide a test or listening relay at the subscribers station,

' connected to the telephone wire circuit and controlled by a radio operator at central to connect thesubstation radio receiving apparatus or circuits to the wire circuit for telephonie transmission thereover to 'central,f

whereby thesaid radio `operator may listen to the actual sounds received and reproduced at the'substation while broadcasting, with a view to the regulation and adjustmentof the transmitting instrument `or the receiving instrument, or both. In the present case, we provide for such supervision by connecting a telephone transmitter to the contacts of the listening relay, and so relating said transmitter to the 'receiver or loud speaker'of the radio receivin set that direct mechanical conduction o sound waves takes place between them, and atest of the complete perfomance ofthe vapparatus as a whole is possible. I

Our invention is illustrated in the accompanying drawings,.in which Fig. 1 is a diagram showin lice having a tele hone switc acentralfofboard. and a radio switchboar a subscribers 'stationequipped with a. telephone and a radio 'receiving set, and the ine circuit therefrom to central.

Fig. 2 is a modification of the subscribers loud speaker and audio supervisory means.

Fig. 3 is a side view of the combined loud slpeaker and vtelephone transmitter' shown iagrammatically inFig. 1. r

Referring to the drawings, C is the central oice which for convenience is shown equip ed with manual apparatus, but which may ave automatic switching apparatus, `for the interconnection of telephone lines, or for the radio station control, or both. The line 16--17 is connected as usual to terminals on the telephone switchboard and to one or more multiple terminals on the radio switchboard, where the radio operator has cord circuits typified at Px, equipped with a switch Kx for connecting battery to the tip side of line, the cut o'- relay of the line being at the same time energized teclear said side ofrground at the central office, Vwhich is normally connected through the windings of the line relay.

At the substation A, the telephone T is a standard common battery instrument set. The radio receiving apparatus is equipped with another telephone set, comprising a transmitter-T', receiver t', induction coil I, switch H and condensers g3, g, The radio set in itself forms no part of the present invention, but to supply a loud speaking horn for our purposes, is shown as having a detector tube 30, and two stages of audio amplitication by ltubes 31 and 32.. The usual transformers 3334, 35 are provided,A with batteries A and 'B for filaments and plates..

Thehorn 36 and the switch H are so related that when the telephone T is turned up to open the switch H it will be in position to receive sound waves from the horn. When the switch H is closed-it closes the filament circuits as follows: A', 25, 42, H', 41, filathe radio operator at central can close 'the filament circuit and also the circuit of transmitter T by energizing relay L5. For this purpose,2key KX is closed, and battery current Hows' over tip side 16 of line to the p ments, battery. When the switch is open,

substation, thence through` back -contact of cut of `relay L 4 by wire 26 to Ls and round. Ll5 becoming energized, closes the fo lowing circuits: filament circuit from A', 25, 27 37,

43; transmitter circuit from A to 25, 27", T',

I, and back to battery, shown as by ground return, but may be by wire; line transmission circuit: 16, contact of L, 26, 27, 39, q,

t', -I q, 40, 27", .back contact of L, and so to sleeve'side 17 of line. The operator thus controls both the filament circuit and *the repeat back circuit, and may receive the actual-sound waves produced b the loud speaker, by transmission throng the bod or frame of the horn thereotl and throug the arm of the transmitter T joined to the horn at J 2 (see Fig. 3). The arrangement of this transmitter arm 1t will be noted, is such as to permit the transmitter itself to be used when desired as a mute to muiie the i sound proceeding from the horn. The mech-anical structure of this device vis best shown in Fig. 3 where T indicates the trans` mitter and J2 represents the hinged joint made with firm connection between its. relatively movable partito render it a goodconduotor of sound vibration. In this form, we provide switch H in the form of a push button with normal open contact arranged to be closed b the transmitter when pushed down into tie dotted line position, in which osition it will be noted the transmitter may e employed bythe subscriber for ordinary telephonic purposes. The transmitter may also be thus employed without closing the contacts of switch H by adjusting the arm in an intermediate position.

Fig. 2 shows a modification in which the transmitter T is permanently secured by rigid mechanical means on the neck ofthe horn 36, so that sound vibrations may be `directly communicated to the transmitter.

In this case the switch H may remain in the form shown in our patent but would have to be worked manually to close the filament circuits.

It is to be understood that the mechanical connection of the transmitter may be varie-d without departing from thc invention, as for example by connecting it on a metal rod or other metal connection to the base or source of vibration of the loud speaker.

We claim:

1. A combined superaudio frequency and telephone transmission system comprising a receiving station, a supervising station there-l fore, and a telephone line interconnecting the two, a superaudio frequency receiving and detecting apparatus in said receiving station, vincluding a telephone receiver conyrier may be transmitted at audio or telephone 'frequency over' the telephone line to the supervisory station.

2. In a -combined radio and telephone station, a radio receiving set having a receiver connected to its output circuit, a telephone transmitter mechanically connected with the frame or shell of said receiver and movable thereon, and switching contacts receiver controlling the operating circuits ot' said radio set andthemselves controlled in the movement of said transmitter on said receiver.

3. In a combined radio and telephone system comprising a receiving station having a radio receiving set and a supervisor station connected with the receiving station by a telephone line, a receiver connected to the output circuit of said radio set, a telephone transmitter mechanically mounted on the Vframe or shell of said receiver so as to be movable thereon into and out of operative position, switch contacts also on said receiver controllable in the movement of the transmitter for opening and closing the operating circuits of the radio set, and circuit connecsions from said transmitter to said telephone In testimony whereofwe hereunto aix our signatures.

HARRY F. LowENsTRIN. EDWARD R. CLEMENT.

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