US1673593A - House electric - Google Patents

Description

June 12, 1928. 1,673,593

S. L. SANDERSON RADIO RECEIVING SYSTEM Filed July 1, 1924 Fly. 1.

- INVENTOR WITNESSES:

v I She/don L.6anderson.

ATTORNEY Patented June 12, 1928.

UNITED STATES PATENT OFFICE. I

SHELDON L. SANDERSON, F WILKINSBURG, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

RADIO RECEIVING SYSTEM.

Application filed July 1,

My invention relates to radio receiving systems and particularly to Vernier tuning devices therefor.

One object of my invention is to provide a radio receiving system that is suitable for the reception of a plurality of groups of wave lengths.

Another object of my invention is to produce vernier tuning means in combination with a radio receiving system.

Another object of my invention is to produce a radio receiving system having a single inductive tuning device and a plurality of capacitive tuning devices that are adapted to vernier adjustment.

In the prior art of the reception of radio signals, it has been found convenient to construct a radio receiving system comprising an aerial, a series condenser, a variometer, a ground connection and a detector. It has also been common to use a plurality of series condensive means connected for alternative use according to the wave length which it is desired to receive. In the prior art, the plurality of series condensers have frequently been made each of a fixed value, leaving the tuning entirely to movement of the variometer and to choice of a larger or smaller series condenser.

hly invention comprises means whereby a plurality of series condensers may be used with a single inductive tuning means and, in addition thereto, means whereby a Vernier condenser is provided which is operative with either of the series condensers- Other objects and structural details of my invention will be apparent from the following description when read in connection with the accompanying drawing wherein:

Figure 1 is a diagrammatic view of a radio receiving apparatus and circuits according to my invention, and

Fig.2 is a plan view of a radio receiving apparatus constructed according to my invention.

In Fig. 1 a radio system comprises an aerial 1, a ground connection 2, a tuning variometer 3, and fixed inductances 1 and 5 in series between the aerial 1 and the ground 2. To one terminal of the variometer 3 are connected one terminal each of two conden sers 6 and 7, the other terminals of which are connected to the binding posts 8 and 9 that are; adapted to be connected to the aerial 1924. Serial No. 723,475.

1 by a lead-in wire 11. An adjustable vernier condenser 12 is connected between the binding posts 8 and 9.

The receiving apparatus contains, in addition, a triode 14, the filament circuit of which contains a rheostat 15, the grid circuit of which contains a grid leak and grid condenser assembly 16 and the plate circuit of which contains a feedback variometer 17. There are further supplied the customary A battery A, B battery B and the customary telephones T.

Referring to Fig 2, a tuner control 20 is provided for the variometer 3. Another control 21 is provided for the plate variometer 17, a control 22 for the rheostat 15 and a Vernier control 23 for the Vernier condenser 12. Triode 14 is placed beside rheostat control 22, and the circuits are placed within the container.

In the operation of my device, the aerial 1 may be connectedby the lead-in wire 11 to the binding post 8. The receptor circuit then comprises the aerial 1, the lead-in wire 11, the binding post 8, the condenser 6, the tuning variometer 3, the fixed inductances 5 and 4t and the ground connection 2. Rough tuning may then be efiected by adjustment of the variometer 3. The condenser 6 is shunted by condensers 7 and 12 in series, condenser 7 being substantially larger than condenser 12.

By this connection, the total capacitance, in series between the aerial 1 and ground and in series with the inductance 3, is fixed by the value of the condenser 6, plus the reciprocal of the sum of the reciprocals of the values of the capacitance in the condensers 7 and 12. Adjustment of the condenser 12 thereby varies the total capacitance in the circuit and effects very accurate tuning of the circuit of the incoming signals. The condenser 12 being small, a considerable movement of its dial is required to produce a measurable change in total capacity and noticeable effect upon the tuning of the receptor circuit.

When it is further desired to receive a diiferent wave length, the lead-in wire 11 may be transferred from the binding post 8 to the binding post 9, whereupon the capacitance 7 becomes the main series condenser and, this being of different value than the capacitance 6, the circuit can be made resonant to a different group of radio frequencies than that to Wlllllll'f was resonant when the condenser 6 was the main series condenser. As before, rough tuning to the newly desired frequency maybe accomplished by the -variometer 3. The total series capacitance then becomes equal to the capacitance of the condenser 7 plus the reciprocal of the sum of the reciprocals of the capacitance of the condenser 12 and the condenser 6. Again, the value of the total series capacitance is subject to a slight adjustment by a considerable movement of v the condenser 12.

By the addition of the Vernier condenser,

before described, my invention makes it possibleto produce a radio receiving system having several series condensers that may be connected, atthe will of the operator, for the reception of different groups of radio frequency signals, and a venier condenser co-operatin'g therewith, which gives f ne,

- of my'invention in the accompanying draw: in'gsfit is capable of various mod ficatlons and changes Without departing from the spirit thereof and it is desired, therefore,

that only such limitations shall be imposed thereon as are indicated in the prior art or in the appended claims.

I; claim as my nvention: M 1. In radio receiving apparatus, an 1n-- ductor adapted to be connected to groun.d,:

a network comprising a plurality of fixed condensers oi dissimilar capacities shunted by a variable condenser, a connection from. said inductor to a point intermediate said fixed condensers, and means whereby a radiant-energy collecting device may be at will connected to either plate of said variable condenser,whereby the system is effective over a plurality of wave-length ranges.

2.111 radio receiving apparatus, a variable inductor adapted to be connected to ground, a network comprising a pair of fixed condensers of dissimilar capacities shunted by a variable condenser having a capacity less than that of either of the fixed condensers, a connection from said inductor to a point intermediate said fixed condensers and means for at will connecting a radiant energy receiving device to either plate of said'i ar'iable condenser, whereby the system may be rendered'receptlve over a plurality of wave-length ranges by changing the connection of the energy receptor to saidvariable condenser. 1

In testimony whereof, I have hereunto subscribed niy namethis 23rd day of June SHELDON L. SANDERSGN'.

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