US1912387A

US1912387A - Radio signaling system

Info

Publication number: US1912387A
Application number: US350749A
Authority: US
Inventors: William L Seibert
Original assignee: Individual
Current assignee: Individual
Priority date: 1929-03-28
Filing date: 1929-03-28
Publication date: 1933-06-06
Anticipated expiration: 1950-06-06

Description

RADIO S IGNALING SYSTEM Filed March 28. 1929 TOAUDIO HI'I'I'FL- INVENTOR '25 same radio frequency.

Patented June 6, 1933 WILLIAM L. SEIBERT, or ronrrmoiv vrou'rn ew annsnv.

RADIO SIGNALING SYSTEM 7 Application filed March 28, 1929 Serial No. 350,749.

(GRANTED unnnn rnn ACT or MARCH 3, 1883, As mammal) APRIL at, 11925; 370 as. 757) The in entiOn described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

'6 This invention relates to radio communication systems, and more particularly to transmitting and receiving circuits using vacuum tubes. The systems used previously have ordinarily included substantially complete separate circuits and tubes for transmitting and receiving.

One of the objects-of my invention is to utilize a single vacuum tube and associated circuits for both transmitting and receiving, thus effecting a reduction in quantity of apparatus and simplification of circuits required.

A further object is to provide automatic 7 change of plate current as required for the 29 purposes of transmitting and receiving.

A still further object is to utilize a single oscillating tube circuit for both transmission and reception, thus enabling the transmitter and receiver to operate on substantially th A clear understanding of the invention may be had by reference to the following description of a complete embodiment which is illustrated in the accompanying drawing.

39 In this drawing there is shown a schematic arrangement of a vacuum tube oscillator connected to a tuned loop antenna circuit. A telegraph sending key, included in the plate circuit, operates to short-circuit the series resistance in the plate circuit so that full plate voltage is impressed on the tube while transmitting and reduced plate voltage is provided while receiving, as is necessary to obtain sensitive reception.

Referring now to the drawing, a vacuum tube oscillator of the usual form is represented at 1. This is connected to the tuned circuit consisting of loop antenna 2, fixed ratio condensers 3' and 4, and variable con- 4 denser for frequency adjustment 5. Blocking condenser 6 serves to insulate the d. c. plate potential from the tuned circuit. The negative grid bias potential is maintained by potentiometer 7 thru radio frequency choke coil 8. The potentiometer 7 is by-passed for radio frequencies by condenser 9. The plate current is supplied from the battery shown, the plate circuit including 1 0, the primary of an audio transformer providing coupling toan audio amplifier. The plate circuit also includes Ia large resistor lland its audio signal by-pass condenser-12. .The. radio frequency choke coil 18v and condenser 14 serve to preventshort-circuiting the radio frequency potentials, present in theloop circuit. A'telegraphsending key 15 operates 'to short-circuit the primary -10 of the v I audio transformer andthelargefseries-re:

sistance 11, so that fullplate voltage will. be impressed on the tube for-transmitting.

in the tuned loop circuit. When the tele-- A large radio frequency current isthen setup graphsending key 15 is opened, the plate 7 current is greatly reduced and the circuit oscillates weakly, as is required to obtain;

sensitivity for heterodyne reception: of signals. The adjustment of 1 the oscillation amplitude, as required for most sensitive reception, is precisely controlled-by the grid potentiometer-7.

The circuit then operates as, a powerful radio'transmitter when the sending key is closed,.and as a sensitive heterodyne-radio receiver when the sending key is open. As the tuned circuit was the, same for; both transmission and reception, theufrequency of the oscillations Was substantially 'unchanged for sending and receiving.-

' Communication is then quickly establishedbetween two stations. Station A calls station B; Station. B tunes to obtainbeat note of perhaps 1000 cycles and answers call. Station .A will then hear similar beat note of, approximately 1000 cycles, without further tuning adjustment. The transmitting frequencies used by the two'stations will then differ only by' the audio beat. frequency necessary for heterodyne reception.

f The operation of two or more. tubes with plates and grids each in parallel will, of course, change in no way the objects and claims contained herein, which mention one, or a single tube. 1

WVhile I. have described certain forms of my invention in detail, and while I have pointed out certain of the most obvious principles and purposes thereof, I do not intend that the language employed in the following claims shall be limited to the precise features described, but I intend that the claims shall be construed to cover all combinations which are fairly included in the language thereof, when read in View of the prior art regardless of the details and functionsmentioned in the description or illustrated in the drawing.

Iclaim: M

1. A radio signaling system, comprising a singletransmitting and receiving circuit; an electron tube having a plate circuit associated with said single circuit; means operative with the plate circuit to cause said tube to oscillate strongly while transmitting; a source of potential in the plate circuit and means in said circuit for substantially reduc ing the potential to cause said tube to oscillate weakly while receiving.

2. A radio signaling system, comprising a single transmitting and receiving circuit; an electron tube in said circuit; means to cause said tube to oscillatestrongly while transmitting; and means to cause the tube to oscillate weakly while receivin A radio signaling system, comprising a combined transmitting and receiving circuit; an electron tube having a plate circuit operatively associated with said combined circuit; a source of potential in said plate circuit; means operative in said plate circuit to control the value of said potential to cause said tube to oscillate strongly when transmitting and to oscillate weakly as a selfheterodyne detector when receiving.

4. A radio telegraph signaling svstem, comprising a single tuned circuit adapted both for transmitting and receiving; an electron tube having a plate circuit operatively associated with said single circuit; a source of potential in the plate circuit, and means in said circuit to control the value of the potential; and a telegraph key operative with said control means to produce strong oscillations in the tube while transmitting and weak oscillations while receiving. i

5. A radio signaling system, comprising a single tuned circuit for transmitting and receiving; a single electron tube adapted to oscillate into said circuit while both transmitting and receiving; means operative with said tube to cause strong oscillations while transmitting and Weak oscillations while receiving. I

6. A radio signaling system, comprising a combined transmitting and receiving circuit; a tuned antenna circuit associated with said combined circuit; a single electron tube included in said combined circuit and adapted to oscillate into said antenna circuit; means to cause said tube to oscillate strongly ceiving; means in the plate circuit to cause said tube to oscillate strongly while transmitting and weakly While receiving; and

means in the tunedicircult to malntain a substantially constant frequency both while transmitting and receiving. In testimony whereof I afiix my signature.

WILLIAM L. SEIBERT.