US1909981A - Transmission system - Google Patents

Transmission system Download PDF

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Publication number
US1909981A
US1909981A US396960A US39696029A US1909981A US 1909981 A US1909981 A US 1909981A US 396960 A US396960 A US 396960A US 39696029 A US39696029 A US 39696029A US 1909981 A US1909981 A US 1909981A
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United States
Prior art keywords
frequency
frequencies
modulating
circuit
overtones
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Expired - Lifetime
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US396960A
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English (en)
Inventor
Osnos Mendel
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Telefunken AG
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Telefunken AG
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Publication date
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Publication of US1909981A publication Critical patent/US1909981A/en
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    • HELECTRICITY
    • H03ELECTRONIC CIRCUITRY
    • H03CMODULATION
    • H03C5/00Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal

Definitions

  • the present invention discloses ways and means adapted to' improve telephony work especially in radio transmission on waves customarily used in radio work, including ultra-short waves.
  • a transfer element-is inserted which, on the one hand, receives the currents influenced by music or the like, and which, on the other hand, supplies currents whereby the part to be supplied is so influenced that the overtones imparting peculiarity and beauty to the voice, music, etc., and "which normally are of but feeble value, are amplified, while those originally not existing and those totally lacking are produced or restored.
  • this-fundamental wave or .a part there of can be filtered out in well-known manner and be fed to the transfer element heretofore mentioned "and to be described later, while in the latter the, weakened overtones, according to' the reason underlying their original reduction in volume, can be amplified or reinforced.
  • the overtones thus amplified are then fed into a suitable part of the transmitter or receiver, with the result that perfect timbraof the instrument is restored.
  • the tonal qualities of a musical transmission can be improved by causing the octaves corresponding to all or part of .the existing frequencies to sound simultaneously.
  • a bass could be changed into a baritone or a tenor.
  • Tonal quality can be improved according to and within the spirit of this invention by that the frequencies of all of the currents derived from the apparatus are produced in the sequence of the major accord, 4: 5 6.-
  • overtones could'be insured, for lnstance, 1n the following manner.
  • the ensuingnew frequency series are received in well-known manner in. receiver ap, paratus whereby also according to known practice, the overtones 2m1, 9/7122, 9/2223 etc. 45ml, 47712, 4on3 etc. and r P 31ml, 37722, 31713 etc. iml, 4m2,'4m3 etc. 6m1, 6m2, 6m?) etc.
  • the first stage to produce frequencies N im N imZ, N imS etc. consists most suitably of the well-known Carson scheme, which comprises two thermionic tubes a a the output circuits of which are in differential coupling relationship withthe following circuit (antenna, input circuit of amplifiers, or the like), while their grid circuits are fed both with a radio frequency wave N as well as with a modulating 'frequency m which act upon the grids differentially relative to each other, for instance, in such a way that the grids are always acted upon by radio frequency N in the same sense and by the modulating frequency in opposite sense.
  • frequencies ml, m2, m3 known 'manner constitute the first serial stage of frequencies N iml, N imQ, N m3. Now, these frequencies can be etc. transferred in known manner by coupling Z2 to the next circuit, say, the aerial.
  • FIG. 2 illustrates a circuit adapted to could .be fed to an additional simi-v ifs larly arranged stage (1 (1 where they produce in the output circuit these new frequency series Ni3m1, N i 3m2, Ni3m3 etc.
  • the number of stages can be chosen at will, and the couplings k I0 can be adjusted ad lib, or, if desired, some of them may be disconnectec.
  • the arrangement hereinbefore described may be inserted not only between two parts of a transmitter, but also between two parts of a receiver set.
  • melody A will be fed to the aerial in its lower key, and melody B in its upper key (third octave). But if he does the same thing with couplings 70 I0 70 10 then conditions are reversed, i.e., melody will be transmitted in its upper key (third octave) and melody B in its lower key.
  • the scheme shown in Figure 2 may be used at the receiving end instead of at the sending station.
  • steps. of modulating said carrier frequency at signal frequency selecting components of said-modulating frequency and said carrier frequency having a frequency equal to the frequency of the carrier frequency plus the signal frequency, and modulating said components. at signal frequency.
  • Themethod of increasing the range of modulating frequencies for improvingthe tone and timbre in sound transmitted by means of a plurality of transfer elementsinserted between the soundsource and aload circuit whichincludes, the steps of producing a carrier, frequency, modulating said carrier frequency at a signal frequency, impressing said modulated carrier frequency on one of said transfer elements, impressing the modulated carrier. frequency only from said transfer element to said load circuit, selecting a side band produced by the carrier and the signal, combining said side band with the signal frequency, impressing the combined frequencies on a second transfer element, and impressing the resulting frequency components on the load circuit.
  • the method of increasing the range of modulating frequencies for improving the tone and timbre in the transmission of sound signals on a carrier frequency which includes the steps of, modulatingsaid carrier frequency at signal frequency, selecting side bands from said resultant energy, modulating said side bands at signal frequency, and utilizing the resultant energy.
  • the method of increasing the range of modulating frequencies for improving the tone and timbre of sound to be transmitted which includes the steps of, producing a carrier frequency, modulating said carrier frequency with a wide range of acoustic freries of side bands, modulating said side bands at signal frequency and utilizing the energy obtained from the several combinations of high frequency energy with signal energy.
  • rier frequency a source of signal frequency, a plurality of thermionic re1ays,'each having input and output circuits, means for impressing signal frequency on the input cir cuit of each of said relays, means for impressing carrier frequency on the input circuit of one'of said relays, means for selecting the first side band only from the output circuit of said last named relay, meansfor ime pressing said side band on the input circuit of another of said relays, and a load circuit connected with the output circuit of each of 7 said relays.
  • An arrangement for producing signal modulated frequencies in which all of the overtones may be maintained or reenforced' including, a source of carrier frequency, a source of signal frequency, a plurality of thermionic relays, each comprising a pair of thermionic tubes having symmetrical input and output circuits, means for impressing signal frequency on the input circuit of means for impressing carrier frequency on the input circuit of'the first of said relays, and means for selecting from the output circuit of each of said relays a progressive series of side bands means for impressing the side band selected from the output circuits of each of said relays on the input circuit of the following relay, and a load circuit connected with the output circuit of each of said relays.

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  • Electrophonic Musical Instruments (AREA)
  • Reverberation, Karaoke And Other Acoustics (AREA)
US396960A 1928-10-31 1929-10-03 Transmission system Expired - Lifetime US1909981A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE340060X 1928-10-31

Publications (1)

Publication Number Publication Date
US1909981A true US1909981A (en) 1933-05-23

Family

ID=6224600

Family Applications (1)

Application Number Title Priority Date Filing Date
US396960A Expired - Lifetime US1909981A (en) 1928-10-31 1929-10-03 Transmission system

Country Status (3)

Country Link
US (1) US1909981A (fr)
FR (1) FR683984A (fr)
GB (1) GB340060A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2645710A (en) * 1948-03-12 1953-07-14 Hartz Julius Radio transmission and carrier wave modulation

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2645710A (en) * 1948-03-12 1953-07-14 Hartz Julius Radio transmission and carrier wave modulation

Also Published As

Publication number Publication date
GB340060A (en) 1930-12-24
FR683984A (fr) 1930-06-19

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