US2297482A - Portable radio equipment - Google Patents

Portable radio equipment Download PDF

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Publication number
US2297482A
US2297482A US355567A US35556740A US2297482A US 2297482 A US2297482 A US 2297482A US 355567 A US355567 A US 355567A US 35556740 A US35556740 A US 35556740A US 2297482 A US2297482 A US 2297482A
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United States
Prior art keywords
transmitter
voltage
receiver
modulating
portable radio
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US355567A
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English (en)
Inventor
Kuhlmann Walter
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Individual
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Individual
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Publication date
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Application granted granted Critical
Publication of US2297482A publication Critical patent/US2297482A/en
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/44—Transmit/receive switching
    • H04B1/48—Transmit/receive switching in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter

Definitions

  • This invention relates to radio apparatus of the kind comprising a transmitter and a receiver which are operated either on the same wavelength or on different wavelengths, these wavelengths in most cases being in the neighbourhood of each other.
  • the invention is concerned with the constructional arrangement of the above-mentioned portable equipment.
  • the receiver is as a whole or in part utilized for effecting the working point control, that is, the said energy-saving modulation.
  • the expenditure in apparatus is not greater than it is usually. All the parts of such apparatus are dimensioned to be worked at their full load capacity.
  • a certain control power must be produced.
  • a continuous voltage is derived from the modulation currents and is caused, after passing through an amplier, to so influence the grid circuit of a stage of the transmitter, or a screening grid circuit thereof, that the working point of the stage shall be displaced in accordance with the modulation amplitudes.
  • Methods of this kind are known as floating carrier modulation.
  • To properly control the transmitter a certain energy must be delivered by the said amplifier. Such additional energy is not of importance as far as the overall energy saving is concerned in View of the gain in energy obtained by the iioating carrier modulation.
  • the transmitter comprises two stages, namely, a control stage having an electron tube 2 and an output stage having an electron tube 3.
  • tubes 2 and 3 are four-element tubes having cathodes 2l and 22, control grids 23 and 24, screen grids 25 and 26, and anodes 21 and 28, but they may also be pentodes if desired.
  • the control stage may be either a high frequency oscillator or a conventional amplier controlled by a separate high frequency source.
  • the output stage is a conventional amplier, and the two stages may be coupled by any well known means.
  • the receiver comprises three stages 5, 6 and l, stages 5 and 6 being coupled by any Well known means. lThese stages are the usual stages of an ordinary portable receiver. Stage 'l is coupled to stage 6 by a transformer I6 and to the audio reproducer 8 by a transformer Il.
  • the arrangement shown in the drawing may be used for both telephony and telegraphy.
  • keying is effected by means of key 9.
  • switch ll With switch ll in the position shown, as is required for telegraphic operation, the screen grids 25 and 26 are connected to the left hand Contact associated with armature K10. Armature K10 is against the right hand when winding Ill is not energized.
  • windings l and l0 are energized pulling armatures K1 and K10 to the left and thereby applying potential to anodes 21 and 28 and grids 25 and 26.
  • the antenna A is connected to the output stage.
  • the transmitter With the application of the potential to the electrodes of tubes 2 and 3, the transmitter becomes operative to produce oscillations and energizes the antenna thus producing radiations from the antenna. With manipulation of the key 9 corresponding radiations are produced.
  • key 9 When the arrangement shown in the drawing is used for telephony, modulation of the transmitter is eiiected by the microphone 4. As in telegraphic operation the key 9 must be pressed, that is, key 9 in this case acts as a push-totalk key as is usual in portable equipment of the present kind. When the key 9 is pressed, relays I and IU operate as before to connect the antenna to the transmitter and to apply potential to the anodes 2l and 28.
  • the switch I I is reversed and screen grids 25 and 26 are not energized from the same source as the anodes 21 and 28, but instead they are energized over line from the network I3, I4, I9 and I9 where I3 is a condenser, I4, a resistance, I8, a transformer, and I9, a rectifier.
  • I3 is a condenser, I4, a resistance, I8, a transformer, and I9, a rectifier.
  • a residual or at rest screen grid voltage is applied to the screen grids through the resistance I4 which is connected to a D. C. voltage source (not shown) during periods that the carrier is unmodulated.
  • the screen voltage produced is relatively small, and hence the carrier power and energy drain on the power source is low.
  • the arrangement here disclosed renders it possible with an unmodulated carrier value of 40% to obtain a saving of about 60%, and with a mean modulation of to obtain a saving in the battery output of about to 50%.
  • the life of the anode battery thus doubles, If an unmodulated value of the carrier is not utilized, the operation then being based on a value equal to zero, the battery saving may be still further increased without impairing the intelligibility too much.
  • Portable radio apparatus comprising a transmitter and a receiver, means for alternatively operating said transmitter and receiver, means in said transmitter for producing amplitude modulation of the output of said transmitter and means in said receiver for further amplitude modulating the output of said transmitter in accordance with the amount of said firstmentioned modulation.
  • Portable radio apparatus comprising a transmitter having means for producing a carrier voltage, means for producing a modulating voltage, and means for amplitude modulating said high frequency voltage, a receiver having amplifying means, means for selectively operating said transmitter and said receiver, means for conveying a portion of said modulating voltage to said amplifying means, rectifying means coupled to said amplifying means for producing a rectiiied voltage proportional to the mean value of said modulating voltage, and means for further amplitude modulating said carrier voltage by said rectified Voltage.
  • Portable radio apparatus comprising a transmitter having means for producing a carrier voltage, means for producing a modulating voltage and modulating means coupled to said means for producing amplitude modulated carrier waves, a receiver having an amplier, rectifying means coupled to said ampliiier, means for coupling said modulating means to said ampliiier, means for coupling said rectifier to said modulating means, and means for selectively operating said transmitter and said receiver.
  • Portable radio apparatus comprising a transmitter comprising a source of carrier voltage, an ampliiier having a tube comprising a cathode, a control grid, a screen grid and an anode, said amplifier being coupled to said source, a source of modulating voltage coupled to said screen grid and means for radiating radio frequency energy coupled to saidamplier, a receiver comprising an ampliiier, means for coupling said receiver ampliiier to said transmitter amplifier, rectifying means coupled to said receiver amliiier, means for coupling said rectifying means to said screen grid, and means for selectively operating said transmitter and said receiver.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Transmitters (AREA)
US355567A 1939-07-10 1940-09-06 Portable radio equipment Expired - Lifetime US2297482A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE215529X 1939-07-10

Publications (1)

Publication Number Publication Date
US2297482A true US2297482A (en) 1942-09-29

Family

ID=5824445

Family Applications (1)

Application Number Title Priority Date Filing Date
US355567A Expired - Lifetime US2297482A (en) 1939-07-10 1940-09-06 Portable radio equipment

Country Status (4)

Country Link
US (1) US2297482A (enrdf_load_stackoverflow)
BE (1) BE439666A (enrdf_load_stackoverflow)
CH (1) CH215529A (enrdf_load_stackoverflow)
FR (1) FR868488A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2512300A (en) * 1943-09-10 1950-06-20 Transceiver fob two-way
US2515213A (en) * 1943-05-20 1950-07-18 Rca Corp Ultra high frequency communication system
US2531398A (en) * 1943-02-25 1950-11-28 Farnsworth Res Corp Interference transmission system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2531398A (en) * 1943-02-25 1950-11-28 Farnsworth Res Corp Interference transmission system
US2515213A (en) * 1943-05-20 1950-07-18 Rca Corp Ultra high frequency communication system
US2512300A (en) * 1943-09-10 1950-06-20 Transceiver fob two-way

Also Published As

Publication number Publication date
BE439666A (enrdf_load_stackoverflow)
FR868488A (fr) 1941-12-31
CH215529A (de) 1941-06-30

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