Telecommunications – Transmitter – Measuring – testing – or monitoring of transmitter
Patent
1978-11-08
1986-12-23
Ng, Jin F.
Telecommunications
Transmitter
Measuring, testing, or monitoring of transmitter
455226, 455263, H04B 1700
Patent
active
RE0323144
ABSTRACT:
A circuit responsive to an input signal having an unspecified frequency for converting it to a predetermined and constant means frequency, and particularly suitable for incorporation in a modulation measuring instrument, comprises a sampling mixer controlled by a variable frequency oscillator for sampling the input signal to produce an intermediate signal. The mean frequency of the intermediate signal is then compared with a reference representing a predetermined frequency value whereby to produce an error signal, and means responsive to the error signal adjusts the frequency of the oscillator in such a direction as to tend to hold the mean value of the frequency of the intermediate signal at the predetermined frequency value while preserving therein variations in amplitude and/or frequency due to amplitude and/or frequency modulation.
REFERENCES:
patent: 3512089 (1970-05-01), Cushman
patent: 3569938 (1971-03-01), Blair
patent: 3649919 (1972-03-01), Fridman et al.
patent: 3736510 (1973-05-01), Wu
patent: 3753141 (1973-08-01), Van Elk et al.
"Racal Review", pp. 4 & 16, 3/1974.
Publication on Sayrosa Model 251 Automatic Modulation Meter (1972), 2 pages.
Publication on Sayrosa Model 252 Automatic Modulation Meter 5/7/74, 2 pages.
Hewlett Packard Journal (1973), pp. 1-24.
Instruction Manual for Eddystone Radio Model EC 958/12, Nov. 1, 1974.
Instruction Manual for FM/AM Modulation Meter TF2300B, 4/26/74.
Maintenance Manual for Model 9009 AM/FM Modulation Meter, 10/1975.
Microdot Inc. "Model 412 FM Signal Generator-Operation and Maintenance Manual", Jun. 1, 1962.
"Calibrating Mobile Radios" by D. R. Gittens, Jul. 27, 1972.
"New Product Information" on Modulation Meter 9009 by Racal, Jul. 19, 1973.
"New Product Release" on Modulation Meter 9009 by Racal, Oct. 25, 1973.
"Backup Services are also Mobile" by D. R. Greasey, Electronics Weekly, Nov. 7, 1973.
"CATC Electronics News" Relating to Racal Modulation Meter 9009, Dec. 1973.
Irish Patent Application No. 916/73, Laid Open to Public Inspection in Dec. 1973.
"Operating & Service Instructions Issue 1" by Pye Telecommunications Limited, Cambridge, England, 1973.
Schematic of "Eddystone Radio", 1974.
Modulation Meter Type TF2300 Instruction Manual by Marconi Instruments, 1966.
Hewlett-Packard Co. Service Manual on Model 8405 A Vector Voltmeter, 1966.
Hewlett-Packard Co. Application Note 91, Jan. 1968.
Gittins Derek R.
Gregory Michael D.
Ng Jin F.
Racal-Dana Instruments Limited
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