US1704754A - Radio apparatus and method of operating the same - Google Patents

Description

March 12, 1929. MARWN 1,704,754

RADIO APPARATUS AND METHOD OF OPERATING THE SAME Filed June 9, 1925 2 Sheets-Sheet 1 ENTQR.

ATTORNEYS March 12, 1929. Rvm 1,704,754

RADIO APPARATUS AND METHOD OF OPERATING THE SAME Filed June 9, 1925 2 Sheets-Sheet 2 ////////////,i fj

ATTORNEYJ' Patented Mar. 12, 1929.

v UNITED STATES m n. mvnv, or RYE, mcw- YORK.

RADIO APPABAT'IJ'S AND METHOD OF OPERATING- THIE Sm Application filed June 9,

Radio sets as constructed at present have a plurality of tuning circuits with one or more means for tuning the set. In all cases a dial or its equivalent is used and the tuning is accomplished by moving the dial to a point giving the best reception. This method of tuning is objectionable because of the skill required to get the best results and also because of the pains necessary to properly tune the set. In some types'of sets the tuning positions of the dials may be logged, but even this is objectionable because of the necemity of referring to the log book and the care necessary to set the dials exactly according to 5 the log.

Any kind of tuning requiring skill is objeetionable' to the ladies because'of their difficultyjn understanding the operation of the set.

The tuning is usually done by using a variable condenser or reactance, or both. For the purpose of my invention they may be regarded as equivalent.

These devices are provided with a movable tuning means. By movable tuning means or element is meant a tuning means in which the tuning of a circuit is accomplished by relative movement of the associated active parts of a condenser as in a variable condenser, or the associated active parts of an inductance as in a variometer.

I have devised means whereby all of the above objections are overcome and many advantages secured I use the term casual in diflerentiation from hand, which necessitates visual, aural or tactile skill and attention on the part of the tuner.

Radio sets are commonly tuned visually by means of graduated dials orindex plates in connection with a marked point. They are tuned aurally by listening to the sounds in the head phones or loud speaker while moving the tuning members. They may be provided with dials or index plates havin raised characters thereon for the,blind. A1 of these methods require skill, close attention, careful manipulation, accurate observation and considerable time, and generally speaking, some knowledge of the index plate with reference to the diflerent wave lengths or stations is necessary, usually necessitating consultation with a log sheet.

As distinguished from the above, I use the term casual to characterize tuning appli- 1925. Serial I0. $5,878.

ances and methods-by means of which tunmg 1s accomplmhed by semi-automatic o tion of mechanism setinto motion a casual act of the operator without the necessity for careful attention, close observation, and without any knowled e of the relation between the setting of in ex dials and station wave lengths, and without a la se of time. A free and careless motion of t e operator is sufiicient to instantly tune the setto any one of a limited number of previously selected stations. Such a movement as is used in pushing a doorbell button, snapping on an electric light switch, dialing an automatic telephone, changing a phonograph record, is all that is required. Consequently a child, a blind person, a novice who has never seen a radio set, who has no knowledge of wave lengths, log sheets, or dial settings, may instantly tune a simple or com licated radio set to any one of a limited number of stations with extreme accuracy.

It is common experience that in any particular location reliance for real entertainment is usually placed upon a comparatively few radio stations, and while the ability to select reception from a large number of distant stations is frequently desirable for family entertainment, the number offering regular entertainment is strictly limited. Therefore according to my invention the selected stations are accurately tuned by accurate ad- 1' ustments of the tuning means made at leisure and by a skilled tuner or an expert. Unskilled or casual manipulation brings into operation the full benefit of this accurate and skillful tuning and thus makes it easy for the novice to operate the set as well as a skilled operator.

By the employment of my invention any set may be instantly tuned to a predetermined wave length by merely operating a push button, lever or any other equivalent device. This may be accomplished in many wa s, that is to say, by coordinating the usual 'als so thatthey will be moved to any one of a plurality of predetermined positions; b mechanically prearranging the tuning (iavices so as to move to a predetermined definite position when actuated; or by otherwise so arranging the circuits or tuning devices that the set will respond to agiven wave length upon the actuation of a single device.

I have illustrated a specific embodiment of my invention in the accompanying draw- 110 ings and my invention will be better understood by reading the following description taken in connection with said drawings, in which Fig. 1 is a plan yiew partially in section, showing of my lnvention;

Fig. 2 is a section on line II II of Fig. 1;

Fig. 3 is a section on line IIIIII of Fi 1, showing the tension releasin means;

Fig. 4 is a section on line IVI\ of Fig. 1, showing the battery switch and means for operating the same. I

The arrangement here shown is constructed and operates substantially as follows: The usual panel 1 is provided with a series of openings through which the operatin rods 2, 3, 4, 5, 6, 7, 8 extend. This pane also carries the usual tuning dials 9 and 10. Supported back of the panel and within the cabinet of the set is the operating mechanism for tuning the set as above outlined. This mechanism is supported by a frame 11 of any desired construction. Usually the frame would be made of metal, but obviously it may be made of insulating material if desired. Also mounted in the cabinet are the tuning condensers 12 and 13. Each of the condensers, as usual, is provided with fixed plates and movable plates. These condensers may be connected in the receiving circuit according to any desired hook-up and are usually employed with corresponding inductances so that the set may be tuned to any desired wave length. In the mechanism shown the dial 9 is connected with the rotor of the condenser 12 through a shaft 14, bevel gears 15 and 16, the gear 16 being mounted upon the rotatable shaft 17 of the condenser 12. The dial-1O is connected with the condenser 13 by similar mechanism comprising the shaft 18, bevel gears 19 and 20. The gear 20 is fastened onto the end of the rotatable shaft 21 of the condenser 13. By the mechanism above described the set may be tuned by manipulatin the dials 9 and 10 in the usual way, provided the rod 7 has been pushed into the position shown in Fig. 3 for a reason which will appear later.

I will now describe the operating means bywhich the condensers 12 and 13 are automatically moved to predetermined positions.

Each of the rods 2 to 6 has on the end thereof extending through the panel 1, an index button 22, 23, 24, 25, 26, respectively. These rods and index buttons may for simplicity be designated as manuals, which designations seems apt by whatever power or means said manuals are actuated. A shaft 27 extends across the mechanism shown in Fig. 1 and is rovided with a gear 28. This gear meshes with a gear 29 fastened on a shaft 17 of the condenser 12.- The shaft is journaled in the frame 11 in any suitable manner.

A similar shaft 30 extends across the mech the mechanism of one embodiment anism and has a gear 31 thereon which meshes with the gear 32 on the shaft 21 of the condenser 13. Mounted on the shaft 30 is a link connection 33 for each rod 2 to 6 inclusive. This connection is best shown in Fig. 2.

The structures responding to the actuation of the various rods 2 to 6 are substantiall identical and an explanation of one wi 1 therefore be suificient. I will describe the mechanism connected with the rod 6. The rod 6 is hollow and slides over the screw threaded rod 34 until the end of the rod 6 engages the nut 35 which is micromctrically adjustable on the rod 34. When adjusted to the desired position the nut 35 is locked by the nut 36. The position of the nut 35 determines the position of the plates of condenser 12 for the wave length to which the set is responsive when the button 26 is pressed to t e position shown in Fig. 1.

The upper member 37 of the link connection on shaft 30 is connected with a hollow sleeve 38, slidable on the rod 34. A knurled nut 39 is placed on the rod 34 and after adjustment to the desired position is locked by a similar nut 40. The posit-ion of the nut 39 on the rod 34 cooperates in the determination of the wave length to which the set is responsive, because it controls the position of the rotor of the condenser 13, as will be later explained. Fixed on the rod 34 is*a sleeve 41 to which is connected link members 42 and 43. The member 43 is mounted so as to move freely on the shaft 27. An arm 44 rigidly fixed on the shaft 27 has a rod 45 which engages the link member 43. This rod extends across the mechanism shown in Fig. 1 and is supported near each end by arms 44.

Its function in the operation of the device will be explained later.

A rod 46 extends across the rear of the mechanism shown in Fig. 1 and is provided with two separate sleeves 46 and 46". Springs 47 are coiled around these sleeves. One end of each spring is anchored to a pin 48 fastened to the frame 11 and the other end is connected to the members 49. The members 49 are rigidly fastened to the sleeves 46 and 46. A member 50 is rigidly fastened on one end of the sleeve 46 and a chain 51, or other connecting means is connected at one end to the members 50. The other end of the chain 51 passes over a sprocket or is otherwise wrapped around the shaft 21 of the condenser 13. A similar member 52 is connected with the sleeve 46 and a similar member 53 connected therewith and passes around the shaft 17 of the condenser 12. This mechanism we ates a constant tendency on the part of the rotors of the condensers 12 and 13 to move to that position indicated as zero on the di'als 9 and 10. This spring mechanism also create; a constant spring tension on the condenser shafts in opposition to the movement of the rods 2 to 6, inclusive, and thus eliminates lost motion and renders the set of the condensers accurate, as will appear later.

A spring 54 surrounds the rod 6 and opposes the inward movement of the rod, as shown in Figs. 1 and 2. One end of the spring is anchored against a member of the frame 11 and the other end engages a catch 55 rigidly mounted on the rod 6. The tendency of the spring 54 is to push the rods 2 to 6 to the position assumed by the rods 2 to 5, inclusive, as shown in Fig. 1.

Means are provided by which any one of the rods 2 to 8 when moved into the position assumed by the rod 6 in Fig. 1, will be held in that position until some one other of the rods is moved inwardly, whereupon the other will be released. This mechanism may be of any desired form and per se does not constitute any part of my invention. The mechanism shown comprises a slide plate 56 with a plurality of openings therein through which the catch members 55 may pass. Each of the members 55 is provided with a tapered portion which enters the corresponding opening in the slide plate 56 and in passing through the opening moves the plate so as to release any other member which may have previously pushed through its corresponding opening. As soon as any given member 55 has been pushed through (as, for instance, that connected with the rod 6), a spring 57 moves the plate 56 so that the squared portion of the member 55 catches on the side of the member 56 andis held in the inward position until released by the actuation of one of the other rods, or other releasing means. From this, it will be evident that only one of the rods 2 to 8, inclusive, may remain in the inward position at one time. The advantage of this will be apparent later.

Connected with the rod 7 is a link member 58 freely rotatable upon the rod 46. This member has a pin 59 therein which engages the members 49 which are rigidly attached to the sleeves 46 and 46 so that when the rod 7 is pushed inwardly the sleeves are rotated so as to release the tension of the springs 47 and move the mechanism to the position shown in Fig. 3. a This completely releases the spring tension normally existing on the condenser shafts and thereby renders them responsive to the adjustments of the receiver by the dials 9 and 10 in the ordinary way. The operation of the device above described is as follows: In order to adjust the mechanism to respond to a given wave length when the rod 6, for instance, is moved to the position shown in Fig. 1, the rod is pushed to that position and the nuts 35 and 40 are adjusted on the rod 34 so as to properly tune the set by moving the condenser plates to the shafts 17 and 21, which in turn are actuated by the shafts 27 and 30, respectively. Once the nuts 35 and 40 are placed in the proper position.

they are locked by the nuts 36 and 39, respecmoved to these predetermined positions upon the actuation of the rod 6. Likewise the corresponding nuts on each of the other rods-2 to 5, inclusive, may be adjusted so as to render the set responsive to any other wave length and then looked into place. The lostmotion connection provided by the member 43 and rod 45 permits the different rods 2 to 6 to move the condenser 12 to different predetermined positions. The loose connection between the sleeves 38 and the rods 34 likewise permits the various rods to move the plates of the condenser 13 to different predetermined positions. After the adjustments have been made on various rods all that is necessary to tune in a station is to merely press the button corresponding to that station, whereupon the condensers will be auto: 7

matically moved to an accurate tuning position. If at any time it is desired to disconnect the automatic tuning mechanism, the rod 7 is pushed to the position shown in Fig. 3, whereupon the spring tension mechanism is rendered ineffective and the set is then responsive to a tuning mechanism by use of the dials 9 and 10.

A battery switch is provided on the set and consists of the rod 8 which when pressed to the position shown in'Fig. 4 separates the contacts 60 and 61 which are normally in contact when the rod 8 is in the position shown in Fig. 1. The contacts 60 and (it are supported on the frame 11 by brackets 62, or any other suitable means. The rods 7 and 8 are provided with index buttons 63 and (34, respectively, with suitable legends thereon. The station name or wave length may be placed on the buttons 22 to 26 in any suitable manner.

I might state the chief advantage of my invent-ion to be that of permitting the owner to pretune his set accurately and at leisure to a plurality of selected stations, then throw the set onto any one of the selected stations without any more effort or skill or attention than turning on the lights. In other words, the set is thrown from one accurately tuned condition to another accurately tuned condition and is not detuned in the change-over, as is necessary with the usual dial or hand tuning.

In all the modifications shown and in the foregoing description, I have referred to the tuning element in the form of a condenser. It is well known in the art that an inductance may be used instead of a condenser or the two may be used together. I therefore wish it to be clearly understood that in none of the modifications am I limited to condensers, as I desire to be understood that my invention comprehends the equivalent inductive tuning element. Furthermore, I have illustrated two forms of my invention, but of course have 'not attempted to illustrate all possible modifiinfluence of said spring.

5 factory, but these forms are merely illustrative of the principles of my invention and are not the only modifications thereof, as many slight changes and re-arrangements may be made without departing from my invention.

Furthermore, the principles illustratedare applicable to any type or set whether using one dial or many dials, and I believe their;v

application to'various sets will be obvious to those skilled in the art after reading the examplesabove described.

The term manual as used in the claims is intended to designate the part directly actuated by the operator in tuning the re f ceiver. In the'embodiment shown ,and d6,- scribed the manuals consist of the rods 2 to '6, and the associated index buttons 22,. 23, 24,

and 26. It is my intention that the term if manual as used in the claims shall cover the specific form disclosed and any other 5 form of device having a similar function in the tuning operation.

I claim:

1. In a radioreceiving set, a single tuning element, a plurality of operating means each representing a wave length, each said operating means being operative independent of the movement of the others andbeing micrometrically adjustable and adapted to move said tuning element to a position mechanically determined by adjustment and to automatically lock said element in said'position. Y

2. In a radio receiving set, a slngle movable tuning element, a spring that tends to 1 move said element in one direction, a plu- 40 rality of operating means each representing a- Wave length, each said operating means being operative independently of the others and being micrometrically adjustable and adapted to move said tuning element to a position mechanically determined by said adjustment 7 and to automatically lock said element in said position.

3. In a radio receiving set, a single movable tuning element, a spring adapted to move said element in one direction, a plurality of independent operating means, each representing a wave length, and each of said operating means being adapted to move Said tuning element through lost motion connection to a position mechanically determined v by micrometric adjustment of said operating I means, and means automatically operated by each of said operating means for locking said tuning element in sald position against the p 4. In a radio receiving set, a single movable tuning element, a spring adapted to move said element in one direction, a plurality of independent operating means, each representing a wave length, and each of said operating unlocking said tuning element when any one of said operating means is actuated.

5. In a radio receiving set, a single movable tuning element, a spring adapted to move said element in one direction, a plurality of independent operating means, each representing a wave length, and each of said operating means being adapted to move said 'tuning element through lost motion connection to a position mechanically determined by micrometric adjustment of said operating,

means and means automatically operated by each of said operating means for locking said tuning element in said position against the influence of said spring, and means for manually adjusting the position of said tuning element p independent of said operating means.

senting a Wave length, and each of said op 'eratlng means being adapted to move sa1d'-.v

tuning element through lost motion connection to a position mechanically determined-1.

by micrometric adjustment of said operating means, and means automatically operate by each of saidoperating means for locking said tuning element in said position against the influence of said spring, and means forrendering said spring inoperative.

7. In a radio receiving set, a single movable tuning element, a plurality of independent adjustable operating means, each representing a Wave length and each operating means being adjusted to move said tuning element to a position corresponding to the Wave length associated with said moving means automatically by a single movement of the operator, and means included in each operating means for micrometrically readjustingthe' position of said tuning element after actuating said operating means.

8. In a radio receiving set, a single movable tuning element, a plurality of independent adjustable operating means, each representing a wax e length and each. operating means being adjusted to move said tuning element to a position corresponding to the Wave length associated With said moving means automatically by a single movement of the operator, and means for micrometrically readj usting the position into which said tuning element is moved by the actuation of said operating means.

9. In a'radio receiving set, a single movable tuning element, a plurality of operating means, each representing a wave length, each said operating means being operative indeendent of the movement of the others and iieing micrometrically adjustable after the actuation of said operating means and adapted to move said tuning element to a position mechanically determined by adjustment and to automatically lock said element in said position.-

10. In a radio receiving set. a single movable tuning element, a plurality of manuals, each representing a wave length and having a fixed travel and each being adapted to control the movement of said tuning element independent of the others through a selective connection, and means for micrometrically adjusting the connection between each of said manuals and said tuning element so that a single movement of the manual through its normal travel will cause said tuning element to move positively and exactly to a position determined by said micrometric adjustment.

11. In a radio receiving set, a single movable tuning element and a means for manually adjusting the same and a plurality of independent operating means normally disengaged from said tuning element, each having an individual micrometrie adjustment whereby movement of said tuning element may be exactly determined and each of said operating means being adapted to automatically engage said tuning element and move it to a point determined by said adjustment when said operating means is actuated independently of the other operating means.

12. In a radio receiving set. a single movable tuning element, a plurality of independent operating means, each representing a wave length and normally disengaged from said tuning element, each adapted to automatically engage said tuning element when operated and each having means for micrometric adjustment for determining the position to which said tuning element will move upon operation, and means for automatically locking said operating means in its final position whereby the single operation of an individual operating means will cause said tuning element to move positively and exactly to a position corresponding to the wave length for which said operating means is adjusted and lock the same in such position.

13. In a radio receiving set, a single movable tuning element, a plurality of rigid operating manuals each representing a wave length and adapted to a definite travel, micrometrically adjustable operating means associated with each manual, means for automatically engaging said operating means with said tuning element and moving it to the position mechanically determined by adjustment of said operating means when said manual is operated, whereby a single definite movement of the operator will tune the tuning element to the wave length corresponding to said manual.

14. In a radio receiving set, a single movable tuning element, a plurality of rigid operating manuals, each adapted to move said movable tuning element and each representing a wave length and each adapted to travel between fixed limits, micrometrically adjustable means bctwecn said operating manuals and said tuning element whereby the ultimate tuning positions of said tuning element are determined by said micrometrically adjustable means. i

15. In a radio receiving set, a single movable tuning element, a plurality of adjustable operating means normally disengaged from said tuning element, each representing a wave length and each operating means including means for automatically bringing said operating means into'engagement'with said tuning element when said operating means is actuated, whereby said tuning element is caused to move to apredetermined mechanically fixed tuning position upon the actuation of an operating means.

16. In a radio receiving set, a single movable tuning element, a spring directly conneoted thereto and adapted to move said element in one direction, a plurality of operating means, each representing a Wave length and each operating means being adapted to move said tuning element independently, each said operating means including a rigid micrometrically adjustable abutment adapted to automatically oppose the action of said spring and fix the tuning position of said element.

17 In a radio receiving set, a single movable tuning element, a plurality of manuals, each representing a wave length and each having a definite travel, independent operating members, each controlled by a corresponding manual and adapted to automatically engage and move said tuning element upon the operation of the corresponding manual, and means for micrometrically adjusting each operating member so as to determine the ultimate tuning position of said tuning element resulting from the operation of the selected corresponding manual.

18. In a radio receiving set, a single movable tuning element, a plurality of independent micrometrically adjustable operating means, each representing a wave length and each including a manual, means for automatically operatively engaging said operating means with the tuning element upon the operation of its manual, and means including a lost motion device for determining the ultimate tuning position of the tuning element upon the operation of the said manual.

19. In a radio receiving set, a single movable tuning element, a plurality of operating means for operating said tuning element, each of said operating means including a manual v and each adapted to move said tuning element independently of the others, and means for locking each operating means in a fixed position after operation, and means capable of micrometric adjustment for operatively connecting each manual with its operating means.

20. In a radio receiving set, a single movable tuning element, a plurality of manuals, each associated with a given wave length, actuating means between each of said manuals and, said element, means for locking each manual in a fixed position after operation and micrometrically adjustable connections operatively connecting each of said manuals with the corresponding actuating means.

21. In a radio receiving set, a single movable tuning element, a plurality of rigid operating rods, each corresponding to a wave length, each rod having adjustable means for moving said tuning element to a fixed position corresponding to the adjustment of said adjustable means.

22. In a radio receiving set, a single movable tuning element, a plurality of rigid operating means, each including a manual and veach corresponding to a wave length and each adapted to automatically engage said tuning element and a plurality of micrometric adjusting means, each associated with a particular operatingmeans only, whereby the ultimate tuning positions of said tuning element are determined by the micrometrically adjusted means.

23'. In a receiving set, the combination of a shaft, a variable condenser having a movable element mounted on said shaft, a plurality of independently operatable rigid operating manuals adapted for longitudinal movement, adjustable means for operatively connecting each of said manuals to said shaft, whereby each of said manuals may cause said tuning element to be moved to a selected operative position corresponding to the adjustment of the adjustable means associated with said manual.

24. In a radio receiving set, a single movable tuning element, a plurality of rigid operating members, each adapted to move said movable tuning element and each representing a wave lcngthand each adapted to travel between fixed limits, each having micrometric metrically adjustable operating means associated with each manual, means for automatically engaging said operating means with said tuning element and moving it to the positlon mag-m.

mechanically determined by adjust ment of said operating means when sai manual is operated, whereby a single definite movement of the operator will tune the tuning element to the wave length corresponding to said manual, and means for manually operating said tuning element independently of said automatic means, whereby the set may be manually tuned.

26. In combination, with the movable element of a resonance-varying device of a radio receiving system, of a plurality of selectively operable manuals, movable means common to all of said manuals and acting upon operation of each thereof to effect the movement of said movable element, and a plurality of individually micrometrically adjustable means,

each serving to adjustably fix the operative relationship between'said movable means and one of said manuals, whereby the adjustment of each of said adjustable means will determine the ultimate tuning position assumed by said movable element.

27 The combination, with the movable element of a resonance-varying device of a radio receiving system, ofa plurality of selectively operable manuals, movable means common to all of said manuals and acting upon operation of each thereof to effect the movement of said movable element, and a plurality of individually micrometrically adjustable means cooperating with said. movable means and separately acted upon by each of said manuals,

whereby the individual adjustment of said adjustable means will determine the ultimate tuning position to which the operation of each of said manuals will eifect the movement of said movable element.

28. The combination, with the movable element of a resonance-varying device of a radio receiving system, of a plurality of selectively operable manuals, a driving member common to all of said manuals and free from connecti on therewith acting upon movement thereof to effect the movement of said movable element, and a plurality of individually adjustable abutments, each acting upon operation of one of said manuals to transmit movement therefrom to said driving member, whereby the individual adjustment of said abutments will determine the ultimate tuning position to which the operation of each of said man uals will effect the movement of said driving member.

29. The combination, with the movable element of a resonance-varying device of a radio receiving system, of a plurality of selectively operable members, movable means common to all of said members and acting upon operation of each thereof to effect the movement of Ill said movable element, and a plurality oftindividually adjustable means, each serving to adjustably fix the operative relationship be- I of said adjustable means will determine the ultimate tuning position to which the operation of each of said members will effect the movement of said movable element.

30. The combination, with the movable ele- I tion of each thereof to effect the movement of I said movable element, and a plurality of in-;

dividually adjustable abutments cooperating with said movable means and each acted upon by one of said members, whereby the individual adjustment of said abutments will determine the ultimate tuning position to which the operation of the respective members will efi'ect the movement of said movable element.

31. The combination, with the movable element of a resonance-varying device of a radio receiving system, of a plurality of selectively operable members, and motiontransmitting means adjustable with respect to each of said members individually and acting upon operation of each of said members to effect the movement of said movable element, the adjustment of said means with respect to each of said members determining the tuning position to-which said movable element will be moved upon the operation of each of said members.

32- The combination, with the movable element of a resonance-varying device of a radio receiving system, of a plurality of a 1,704,754.Harry N. Marvin, OPERATING THE SAME.

selectively operable manuals, and motiontransmitting means adjustable with respect to each of said manuals individually and actuated thereby to effect the selective movement of said movable element to diiferent predetermined tuning positions, the tuning positions of said movable element upon the operation of each of said manuals being determined by the adjustment of said means with respect thereto, whereby the selective operation of said manuals will change the resonance of said radio receiving system, thereby making it responsive to different predetermined Wave lengths.

38. In a radio receiving set, the combination of a movable tuning element, a support therefor, driving means operatively connected with said tuning element, a plurality of actuating means for controlling the driving means, each of said actuating means being associated with a given wave length, and means including a plurality of adjustable members for operatively connecting each of said actuating means with said driving means.

34. In a radio receiving set, the combination of a movable tuning element, a plurality of manuals, each associated with a wave length and each adapted upon operation to apply moving force to said tuning element,

and micrometrically adjustable means associated with each manual for determining the position to which the tuning element will move when said manual is operated.

HARRY N. MARVIN.

DISCLAIMER Rye, N. Y. RADIO APPARATUS AND METHOD OF Patent dated March 12, 1929. Disclaimer filed November 26, 1937, by the patentee.

Here? enters this disclaimer to claims 23, 29, 30 31, 32, and 33 of said atent. fictal Gazette December 28, 1937.] p'

. ww DISCLAIM ER 1,704,754.Harry N. Marvin, Rye, N. Y. RADIO APPARATUS AND METHOD OF OPERATING THE SAME. Patent dated March 12, 1929. Disclaimer filed November 26, 1937, by the patentee.

Hereby enters this disclaimer to claims 23, 29, 30, 31, 32, and 33 of said patent.

[Ofliciql Gazette December 28, 1937.]

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