US1888177A - Radio system - Google Patents

Description

'Nov. 15, 1932. T. P. LITTLEPAGE, .JR

RADIO SYSTEM Filed Dec. 15.

Patented Nov. 15, 1932 THOMAS P. LITTLEPAGE, JR; OF WASHINGTON, DISTRICTOIE COLUMBIA nAnIo sys'rn Application filed December 13, 1927. Serial No. 239,766.

This invention relates to improvements in radio systems and particularly to such systems in which it is desired to use plug-in inductances for various bands of frequencies.

In radio systems covering a'wide range of frequencies it has been the practice to employ more than one radio set to cover the entire range of frequencies, one set for the low I er frequency bands and another for the hlgher frequency bands.

It has also been the practice to some extent to employ a single radio set with a plurality of inductance units, each madeup for a different frequency band,.and to plug into the set one of these units corresponding to the frequency band over which it is desired to operate. In such arrangements, while the inductances corresponding'to the frequency I bands desired to be covered, could be readily changed, the difficulty was encountered that the capacities employed could not be varied to the extent necessary to get the best results, and besides more inductance units were necessary to cover the full frequency range than are required in the arrangement disclosed in this invention. V

An object of'this invention is therefore to provide simple and convenient means'whereby different inductance units may beplugged into the set, and at the same timethe capacity units of the set rearranged to provide a capacity arrangement most-desirable. for the inductance unit corresponding to the fre quency band desired to be covered. 7

Another object is to adapt simultaneously capacityand inductance values of the set to suit the frequency band corresponding to the inductance unit employed. It is most essential, and a decided advan tage, particularlyin short wave work, to have a device which introduces the least amount of capacity due to its own structure. Pre

viously known devices used on short wave'sets have proven either so cumbersome or have introduced so much unwanted capacity in the circuit that they have been of very little value practically.

In the practice of this invention in which the capacity units of the set are re-arranged when the inductance units are changed only forlong-wave operation, 1

Fig. 3 shows a circuit diagram corresponding to that in Figure 1 from which the inductanceunit has been removed,

Fig. l-shows diagrammatically an induce tance unit designed for short wave operation with additional contacts for controlling other circuit connections, and I I Fig. 5 shows a slmilar inductance unit designed for long wave operation and provided with-extra contacts for making certain de- I sired connections when the unit is applied to the arrangement shown in Figure 3;

The'invention is illustrated in one ofitsforms in connection with a regenerative receiving circuit as shown in the drawing.- Its use however, is not limited-to; a regenerative circuit as-it will be clear to those skilled in the art that it is applicable'to other types of receiving circuits as wellas'to broadcasting circuits for both short and long wave transmission. I

Fig. 1 shows a diagram of the circuit'connection fora regenerative circuit in which, the antenna is shown at 10, the ground connectionat 11."the primary coil 12, the sec-.

ondary coil 13-and the tickler coil 14". The variable condenser 15, of .0005 mf. capacity is in series with the primary coil 12, and the variable'condenser16, isin shunt to the sec. ondary coil 13'. The grid leak 21 is in the grid circu t and the tickler coil 14' is in the plate circuit of the detector tube 18. The variable condenser 17, of .0005 mf. capacity I has one lead connected to the lead 22which connects the battery 19 to the tube filament,

the condenser 16. secondary coil 13', primary coil 12 and condenser 15. The other termiso I Figure 2 shows a diagram similar in all respects to that of Fig. 1, with the exceptions that the coils 12", 13 and 14: are designed for long wave reception and the variable condensers 15 and 16 have changed places. The condenser 15 is here connected in shunt to the secondary coil 13 while condenser 16 is connected in series with the primary coil 12". By replacing coils 12, 13 and 14', with coils 12", 13 and 14 and reversing theposition of condensers 15 and 16 a very eiiicient arrangement is produced which is effective over a wide range of long wave hands.

This invention is, the more. particularly concerned with the provision of means whereby when the inductance unit comprising coils such as 12, 13 and 14 is inserted connections are simultaneously and simply made whereby the condenser 15 replaces condenser '16 in the circuit andvice versa.

As suggested above inductance units compris ng a plurality of coils, and adapted to be plugged into the circuit have been known, but to cover a wide range of frequency bands it was necessary to provideseveral of these units. The use of a number of suchunits however did not produce the desired result for one reason among others that the range of thecondensers corresponding to such'connected condensers as 15 and 16while suitable for one inductance unit was: not suitable for another inductance unit and'no means was provided for changing condensers or varying their capacities except within very narrow limits. This invention discloses for the first time how it is possible to change the inductance units and at the same=tin1e change'the condensers so that very efiicient results may be obtained over a wide range of wave bands with as few as two inductance units and a single pair of condensers.

In the practiceof this invention the inductance units comprise a form orsupport of cylindrical or other shapeupon which the coils are wound in suitable inductive relation. In the drawing only the base of'the support is shown for the purpose of clearly showing the arrangement of contacts provided for making the desired connections. This base is shown circular for convenience but may have any desired practical shape. On the base of the support or form are mounted a plurality of contacts, one for each coil terminal and since three coils are shown in the form of the invention as'illustrated there are provided six contacts 1, 2', 3, 4, 5, and 6. Contacts 2 and 3 are connected to each other by the connection between the ends of the primary and secondary coils. Contacts 1 and 2 are connected to the primary coil, contacts 3 and 4 to the secondary coil and contacts 5 and 6 to the tickler coil. In cases where more or less coils are used these contacts can be correspondingly altered in number. I

In addition to the above mentioned contacts the base of the support or form also carried contacts A, B, C and D for making the proper connections for the condensers 15 and 16.

It will be noted that contacts A and B are connected to each other and that contacts C and D are connected to each other for reasons which will now be explained. When an inductance unit as shown in Figure 4: which is made up in the form of a plug withcontacts on one end is inserted in or placed upon the receptor It of Figure 3 with the contacts having corresponding parts in engagement, the contacts A and B will engage contacts A and B respectively and complete the circuit from the condenser 15 to the ground connection 11. Contacts C" and D will engage contacts C and D respectively and complete the circuit from condenser 16 to the connection leading from contact A tothe grid leak 21. It will be noted also that contacts E and F will engage E and F respectively but no circuit will be completed by this connection due tothe fact that contacts E and F are not connected to each other.

- With the inductance unit shown on Figure 1 inserted in the system of Figure 3 the circuits will be the same as those shown diagrammatically in Figure 1. If this .unit is removed and the unit shown in Figure 5 inserted in the arrangement of Figure 3 the diagram shown in Figure 2 will be reproduced. In this case the contacts A and D will engage contacts A andD and complete the circuit from the condenser 15 to the lead connecting contact 4 with grid leak 21 and contacts B and C will engage contacts B and C and connect the condenser 16 to the ground connection 11. Contacts E and F will engage contacts E and F and thereby short circuit the impedance device, or choke coil 23. It will be noted that in Figure 5 the contacts A and D are connected together and that contacts B and C are connected together, and the same in respect to contacts E and F. An inspection of the circuit arrangement of Figure 3 with the unit shown in Figure 5 inserted therein will show that the circuit connections are the same as those shown in Figure 2'.

It may also be of advantage in some circuits to provide the inductance units with means to change other impedance devices such as inductive resistance, inductance, or non-inductive resistance at the same time that the capacity units are transposed. One instance of this is illustrated in the present drawing from which it is apparent that the choke coil 23 is short circuited by the contacts E and F of Figure 5. Additional contacts may be provided on the inductance units and re ceptor to control other devices of a similar type when desirable similar systems. 7

t may also be of advantage in some circuits to connect theinductance unit in such a way as to change other inductance values in the set. For instance, the coils in the inductance unit may be in a position in the circuit in which dead end losses are particularly detrimental to eflicient operation of the set. Such dead end losses would result if the coils were tapped and the unused portion remained; but there may be other inductance values in the circuit which need to be changed before the circuit will respond to the desired frequency or frequencies'but the latter inductance, or inductances, may hold such a position in the circuit that its dead end loss will not seriously affect the operation of the set. In such case the inductance unit and the receptor are provided with suitable contacts and connections to simultaneously make the desired connections when the inductance unitis plugged into the receptor. It will be obvious to those skilled in the art that various modifications may be made in 7 my device without departing from the spirit of the invention and therefore I do not limit myself to what is shown in the drawing and described in the specification but only as indicated in the appended claims.

Having thus fully described my said invention what I claim as new and desire to secure by Letters Patent, is:

1. In a radio system in which a plurality of inductance units are employed alternatively in receptor means therefor and in which a plurality of capacities are connected in circuit with said receptor means. the improvement characterized by the fact that means is provided in said receptor means whereby when one inductance unit is employed in said receptor means the capacities bear a certain relation in the circuits and when another inductance unitis inserted in said receptor means the relation of the said capacities in the circuit is automatically altered to bear a different relation to each other.

2. In a radio system in which a plurality of diiferent inductance units are connected alternatively in a receptor means and in which a plurality of capacity units corresponding respectively to the inductance units are connected in circuit with said receptor means, the improvement which consists in means for transposing the capacity units in the circuit by the removal of one inductance unit and the insertion of ceptor means. 3. In ar adio another in the re-v system in plurality of inductance units are employed alternative- 1y" with alreceptor means for short and long Wave operation respectively and a plurality of capacity unitsare connected in circuit withsaid receptor means, the improvement I characterized by the fact that means is provided in said receptor means whereby in shifting from one inductance unit to anotherv the relation of the capacity units in the system is altered to provide a capacity arrangement which'ismost eflicient for theinductance unit employed.

4. Ina radio system using plug-in induc-I are automatically transposed in relation to the circuits of the system.

. 5. In a radio receiver of the regenerative type comprising a receptor means, a plu rality'of removable inductance units to be used alternatively with said receptor means, in combination with a pluralityof condensers connected in circuit with said receptor means, said units and said receptor means being provided with means whereby anexchange of said units transposes the relative positions of the said condensers in the circuit.

6. In a radio receiver employing a plurality of plug-in inductance units'alternatively, a receptor for saidhunits, a plurality of condense-rs connected in the receiving'circuit and co-operating with said units, said receptor and said units having cooperating means whereby the positions of said condensers in the circuit are altered by the removal of one unit and the insertion of another into the receptor for short and long wave reception respectively.

7. In a radio system in which a plurality of plug-in inductance units are employed alternatively, a receptor means therefor, a plurality of capacity units connected .in circuit with said receptor means, and an impedance device are employed, the improvement which comprises, means whereby when the inductance units are shifted in said receptor means, said capacity units are transposed in the circuit and the efiect of said impedance device in the svstem controlled.

8. In a radio receiver comprisin" a plurality of plug-in inductance units, and an impedance device, a receptor for receiving said inductance units, one at a time, a plurality of condensers connected incircuit with said receptor, complemental contacts on said said units connects said condensers and said impedance device in a certain relation, and

another plug-in unit connects said condensers in a different; relation and alters the eflect of the impedance device in the'set.

9. In a radio system in which a plurality of inductance units are. employed alternatively for short and long Wave operation, and a receptor means for receiving said units, one at a time having connected in circuit therewith a plurality of capacity units and an impedance device, the improvement comprising means in said receptor means for simultaneously changing the relation .of the capacity LlIllLS in the system and controlling the effect of the impedance in the system When the inductance devices are shifted.

x In testimony whereof I aflix my signa ture.

THOMAS P. LITTLEPAGE, J R.

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