Patent US4172995A successfully refreshed from Google Patents.
US4172995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
SSB transceiver
Assignee: Alps Alpine Co Ltd
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Filing: 1977-08-22
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Granted: 1979-10-30
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Expires: 1997-08-22
Abstract
Abstract Two pilot signals transmitted at the beginning of transmission from a transmitting station are demodulated in the receiving station and one of the demodulated pilot signals is phase compared with a reference signal generated by the transceiver. A phase comparator generates a control signal having a voltage corresponding to the difference between the compared signals. The control signal is input to a local oscillator of the transceiver which generates a signal to automatically tune the transceiver to the incoming signal frequency.
Inventors
- 👤 Akiyuki Yoshisato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:10
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/38; H04B1/40; H04B1/403; H04B1/405; H04B1/68
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
215 words
In an SSB transceiver having a transmission mode and a receiving mode, comprising tuning means operable in said receiving mode for adjusting the frequency of a received signal, said tuning means including an oscillator having a variable output frequency which is manually adjustable, the improvement comprising means for producing two pilot signals having frequencies differing by a predetermined amount, means operable in said transmission mode for superposing said pilot signals on a transmitted signal, means operable in said receiving mode for demodulating such pilot signals from a received signal, means operable in said receiving mode for switching said tuning means from a manual operating mode to an automatic operating mode in response to a signal having a frequency equal to the predetermined frequency difference between said two pilot signals, means operable in said receiving mode for producing a reference signal having a frequency corresponding to one of said pilot signals, and means operable in said receiving mode for comparing the phases of said reference signal and the corresponding pilot signal demodulated from said received signal and producing a control signal corresponding to the difference between said compared signals, and means supplying said control signal to said oscillator to vary the output frequency thereof, whereby said tuning means will be activated automatically by said control signal.
Claim 2
Dependent Claim
215 words
In an SSB transceiver having a transmission mode and a receiving mode, comprising tuning means operable in said receiving mode for adjusting the frequency of a received signal, said tuning means including an oscillator having a variable output frequency which is manually adjustable, the improvement comprising means for producing two pilot signals having frequencies differing by a predetermined amount, means operable in said transmission mode for superposing said pilot signals on a transmitted signal, means operable in said receiving mode for demodulating such pilot signals from a received signal, means operable in said receiving mode for switching said tuning means from a manual operating mode to an automatic operating mode in response to a signal having a frequency equal to the predetermined frequency difference between said two pilot signals, means operable in said receiving mode for producing a reference signal having a frequency corresponding to one of said pilot signals, and means operable in said receiving mode for comparing the phases of said reference signal and the corresponding pilot signal demodulated from said received signal and producing a control signal corresponding to the difference between said compared signals, and means supplying said control signal to said oscillator to vary the output frequency thereof, whereby said tuning means will be activated automatically by said control signal.
Claim 3
Dependent Claim
17 words
An SSB transceiver is defined in claim 1 in which said oscillator comprises a phased-lock frequency synthesizer.
Claim 4
Dependent Claim
24 words
An SSB transceiver as defined in claim 1 comprising a reference oscillator producing a signal which is frequency divided to produce said pilot signals.
Claim 5
Dependent Claim
30 words
An SSB transceiver as defined in claim 1, comprising means for blocking the received signal from an audio output unless said reference signal frequency equals said corresponding pilot signal frequency.
Claim 6
Dependent Claim
26 words
An SSB transceiver as defined in claim 1, said two pilot signals each having a frequency in an audio band of 300 Hz to 3 kHz.
Claim 7
Dependent Claim
19 words
An SSB transceiver as defined in claim 1, comprising two low frequency oscillators each producing a respective pilot signal.
Claim 8
Dependent Claim
24 words
An SSB transceiver as defined in claim 6, one of said low frequency oscillators also produces said reference signal when in the receiving mode.
Claim 9
Dependent Claim
30 words
An SSB transceiver as defined in claim 1, comprising timing means for limiting said pilot signals for a short time period from the start of transmission of said transmitted signal.
Claim 10
Dependent Claim
26 words
An SSB transceiver as defined in claim 8, said two pilot signals each having a frequency in an audio band of 300 Hz to 3 kHz.
Claim 11
Dependent Claim
34 words
An SSB transceiver as defined in claim 8, comprising means operating in synchronization with said timing means for squelching during said pilot signals an audio signal normally forming a part of said transmitted signal.
Claim 12
Dependent Claim
26 words
An SSB transceiver as defined in claim 10, said two pilot signals each having a frequency in an audio band of 300 Hz to 3 kHz.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-10-29 | 1983-04-30 | 1983-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-10-29 | 1987-04-30 | 1987-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-10-29 | 1991-04-30 | 1991-10-30 | $7700.00 | Window Closed / Lapsed |