US2498689A - Arrangement for modulating continuous waves - Google Patents
Arrangement for modulating continuous waves Download PDFInfo
- Publication number
- US2498689A US2498689A US639288A US63928846A US2498689A US 2498689 A US2498689 A US 2498689A US 639288 A US639288 A US 639288A US 63928846 A US63928846 A US 63928846A US 2498689 A US2498689 A US 2498689A
- Authority
- US
- United States
- Prior art keywords
- valve
- waves
- circuit
- arrangement
- anode
- Prior art date
- 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
Links
- 230000010355 oscillation Effects 0.000 description 10
- 230000008878 coupling Effects 0.000 description 7
- 238000010168 coupling process Methods 0.000 description 7
- 238000005859 coupling reaction Methods 0.000 description 7
- 239000013078 crystal Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 1
- 238000006880 cross-coupling reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 230000003071 parasitic effect Effects 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
- H04L27/04—Modulator circuits; Transmitter circuits
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
- H03K3/78—Generating a single train of pulses having a predetermined pattern, e.g. a predetermined number
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K7/00—Modulating pulses with a continuously-variable modulating signal
Definitions
- the present invention relates to-improvements in arrangements for modulating continuous: el'ecw t'rlc Waves; with particular referenceto keyed radibtelegraph systems.
- radiotelegraph sys tones To modulate a continuous high frequency" carrier wave with an audible frequency wave or tone, and to interrupt the modulated waves at telegraph speed by means of a suitable key or switch arrangement. It is also generally known.
- a receiver for such a system is produced if the:- audio frequency waves modulating" the carrier" waves areof rectangular form, so thatthe carrier wave is in efiect sharply switched on and ofi. It. has been found that best results are obtained when the length of the on periods are approxi mately times thelength of the off periods;
- the-invention provides: an arrangement for a radio telegra-phy transmitter which includes a multivibrator arranged for'generati'ng modulating waves comprising two valves each having an anode; a control; grid-- and a cathode, one of the said valveshavihg an additional anode connected with the" control grid and cathode of the same-valveinsuch manneras t'o-generatemodulated carrier-waves;
- FIGof the accompanying drawing shows:- aschematic circuit diagram of an arrangement according to the invention; Itcomprises two thermionicampl-ifying valves i and 2 ;of whiclhther 55 This arrangement saves a valve toreclaims... (01. 250-17) 2 first has two grids- 3 and cathode 5 and. theanode 6 This valvesmay;.for:z example; beatetro'd'eof which 3; and 4. are respectively the control gridiand; the-screen-gridz 12f.”
- this valve may be a pentode with the supv presser grid (not-shown) connected: to: the oathode in the usual way Valve: 2 needs only one: grid; 1' between the cathode 8 and. tl'ieanodeil, butthis? valve could be a tetrodeor pentodewith the. ad:-- ditional grids (not shown) appropriately polar i'sed.
- the electrodes 3; 4"", 5 of the valve 1: and; the electrodes I 8, 9- of the valve 2 are connected in; aconventional multivibrator circuit; While? the: electrodes 3,. 5 and 6 together form a triodavalve connected to an oscillation circuit which. gener ates the-high frequency carrier waves.
- each 'ofi the. valves is alternatelyblocked and unblocked, and.
- the vaIve-- I can only generate oscillations in those alternate periods of" time during which it is unblocked. Thus it will generate equally" spaced rectangular pulses of high frequency" waves. If the frequency of the multivibrator: is within'the audible range, the effect is equivalent to-modulating the high frequency waves" with: an". audible tone of rectangularwave form.
- Thescreen grid 4 which acts as an anodefor the multivibrator; is connected to the grid- 1. through a condenser I 0; and the anode- 9-is con--- nectedto the grid 3" through: a; condenser l*l',, and through an inductancel2 which acts as-uaz. high frequency choke,- but which can be disreabled" when considering the action of the multi' vibrator:
- Thegrids 1 and 3 are respectively com-- n ected"- to ground through resistance elements- I3. and" f4.
- the nega--' tive terminal of this source is connected to earth; and a smoothing network -l'il comprising two re-- sistances and-a condenseris-associa-ted with thekey for suppressing-switching clicks, accordingto the-usual practice.
- The' grid' a and the anode 6" of thevalve 1 are connected by' a parallel resonant circuit compris ingthe" inductance ZDand condenser 21 which is tuned*to thedesired carrier frequency.
- A* piezo' electric crystal 2 2 or other equivalent series resonant' circuit" or device-tuned to the same irequenc maybe includedin series-with thegricf
- Anode current is suppliedto the anode-6 :fro'm tor 4 interposedbetweenthe the anode potential, and a resistance 25 may also.
- Condensers 26, 21 and 28 are by-pass condensers for the carrier frequency and will be smal1 compared with the multivibrator con- I densers l and H, so that the will have a negligible susceptance at the pulse repetition frequency.
- the cathode is connected to earth through a bias network consisting of a resistance 29 and by-pass condenser 30, and the cathode '8 is connected directly to earth.
- the modulated carrier wave output may be obtained from the terminal 3
- the multivibrator When the key 11 is operated to connect the positive terminal of. the high tension source I8 to the valves, the multivibrator operates in the usual way,.and the time constants of the coupling networks formed by the elements Ill, [3, l5 :and l I, I4, [6 should be so chosen that the valve ll is blocked for a desired fraction of the period, :and unblocked for the remainder.
- the period of the multivibrator could be 1.25 milliseconds
- the time constants could be chosen so that the valve I is blocked for .5 millisecond and unblocked for 0.75 millisecond, giving the preferred ratio of 1.5.
- the constants of the oscillation circuit associated with the anode 6 could be chosen so that the carrier frequency which is generated therein is 500 kilocycles per second, for example.
- the functions of the electrodes 4 and 6 of the valve 1, could be interchanged, if desired: in other words the electrode 4 could serve as the anode for the oscillation circuit, and the electrode 6 could serve as the anode for the multivibrator circuit.
- An arrangement for generating modulated electric carrier waves comprising a first and second thermionic amplifying valve each having an output circuit coupled to the input circuit of the other valve through a corresponding reactanceresistance network in such manner as to generate regularly repeated pulses by which the said valves are alternately blocked and unblocked, and an oscillation circuit coupling the input circuit of the first of the said valves to a second output :erably be small enough for their effects on the multivibrator circuit to be negligible.
- the resistance 29 should be chosen so that the valve I is biased so that oscillations start easily when,
- valve becomes unblocked and the condenser 30 should be large so that the cathode 5 is efiectively earthed at the carrier frequency.
- each of the crosscoupling network circuits for the multivibrator consists effectively of a series condenser ,(H! or H) and two shunt resistances (I3, l'5 or l4, l6)
- circuit of the same valve to generate pulses of carrier waves during the periods when the said first valve is unblocked.
- the said first valve comprises a cathod electrode, anode electrode, and at least a first and second grid electrode intermediate its anode and cathode electrode
- the input circuit of said first valve comprises its cathode electrode and the first grid electrode closest thereto
- one output circuit of said first valve comprises its cathode electrode and the second grid electrode and the.
- second output circuit of said first valve comprises its cathode electrode and its anode electrode
- said second valve comprising a cathode, anode and grid electrode
- the input circuit of said second valve comprises its cathode and grid electrode
- one of said reactance-resistance networks comprises a condenser coupling the first grid electrode to the anode electrode of the second valve and:
- the other reactance resistance circuit comprises a condenser coupling the grid electrode. of said second valve to the second grid electrode,
- the oscillation circuit comprises a resonant circuit connecting the anode electrode of the first valve to the first grid electrode and tuned to a
- An arrangement according to claim 6 com-- prising a piezo-electric crystal connected in series with the parallel resonant circuit and saidfirstgrid electrode, and tuned to the same frequency.
- An arrangement according to claim 11, comprising means for interrupting the modulated carrier waves for signalling purposes.
- interrupting means comprises a twoposition switch adapted to disconnect the source whichlprovides the electron current for the said valve or valves in one position, and to reconnect the said source in the other position- I 3 MAURICE MOISE LEVY.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Processing Of Color Television Signals (AREA)
- Other Investigation Or Analysis Of Materials By Electrical Means (AREA)
- Electrophonic Musical Instruments (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1217/45A GB584642A (en) | 1945-01-15 | 1945-01-15 | Improvements in or relating to arrangements for modulating continuous electric waves |
Publications (1)
Publication Number | Publication Date |
---|---|
US2498689A true US2498689A (en) | 1950-02-28 |
Family
ID=9718164
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US639288A Expired - Lifetime US2498689A (en) | 1945-01-15 | 1946-01-05 | Arrangement for modulating continuous waves |
Country Status (5)
Country | Link |
---|---|
US (1) | US2498689A (fr) |
BE (1) | BE476631A (fr) |
ES (1) | ES178083A1 (fr) |
FR (1) | FR931018A (fr) |
GB (1) | GB584642A (fr) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3022418A (en) * | 1957-07-31 | 1962-02-20 | Ca Nat Research Council | Electronic control circuit |
US3614667A (en) * | 1964-03-19 | 1971-10-19 | Itek Corp | Switchable and modulatory crystal oscillator |
WO2004051842A1 (fr) * | 2002-12-05 | 2004-06-17 | Enocean Gmbh | Dispositif emetteur binaire a modulation directe de l'oscillateur |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1507016A (en) * | 1915-09-23 | 1924-09-02 | Forest Radio Telephone And Tel | Radiosignaling system |
US1948103A (en) * | 1929-07-23 | 1934-02-20 | Rca Corp | Signaling |
US2036078A (en) * | 1935-04-13 | 1936-03-31 | Bell Telephone Labor Inc | Generator of interrupted wave |
US2338395A (en) * | 1940-06-25 | 1944-01-04 | Gen Electric | Signal transmission system |
US2419292A (en) * | 1947-04-22 | System fob transmitting two | ||
US2431179A (en) * | 1942-10-03 | 1947-11-18 | Rca Corp | Multitube self-pulsing oscillator |
US2435262A (en) * | 1944-01-26 | 1948-02-03 | Bell Telephone Labor Inc | Self-modulated oscillator |
-
0
- BE BE476631D patent/BE476631A/xx unknown
-
1945
- 1945-01-15 GB GB1217/45A patent/GB584642A/en not_active Expired
-
1946
- 1946-01-05 US US639288A patent/US2498689A/en not_active Expired - Lifetime
- 1946-06-07 FR FR931018D patent/FR931018A/fr not_active Expired
-
1947
- 1947-05-17 ES ES0178083A patent/ES178083A1/es not_active Expired
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2419292A (en) * | 1947-04-22 | System fob transmitting two | ||
US1507016A (en) * | 1915-09-23 | 1924-09-02 | Forest Radio Telephone And Tel | Radiosignaling system |
US1948103A (en) * | 1929-07-23 | 1934-02-20 | Rca Corp | Signaling |
US2036078A (en) * | 1935-04-13 | 1936-03-31 | Bell Telephone Labor Inc | Generator of interrupted wave |
US2338395A (en) * | 1940-06-25 | 1944-01-04 | Gen Electric | Signal transmission system |
US2431179A (en) * | 1942-10-03 | 1947-11-18 | Rca Corp | Multitube self-pulsing oscillator |
US2435262A (en) * | 1944-01-26 | 1948-02-03 | Bell Telephone Labor Inc | Self-modulated oscillator |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3022418A (en) * | 1957-07-31 | 1962-02-20 | Ca Nat Research Council | Electronic control circuit |
US3614667A (en) * | 1964-03-19 | 1971-10-19 | Itek Corp | Switchable and modulatory crystal oscillator |
WO2004051842A1 (fr) * | 2002-12-05 | 2004-06-17 | Enocean Gmbh | Dispositif emetteur binaire a modulation directe de l'oscillateur |
Also Published As
Publication number | Publication date |
---|---|
GB584642A (en) | 1947-01-20 |
ES178083A1 (es) | 1947-07-01 |
BE476631A (fr) | |
FR931018A (fr) | 1948-02-11 |
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