JPH0528135U - Squelch circuit - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a wireless device that can automatically set the optimum squelch level. [Configuration] FM detection / squelch ON from squelch circuit 3
The signal SC indicating OFF is supplied to the CPU 6. CPU
Is supplied with information signals from the critical level setting switch 7, the title level setting switch 8 and the squelch open setting switch 9, and is used to set the squelch level based on these information signals and the signal SC. Adjust the electronic volume 5. Squelch level signal SQ indicating the squelch level set by the electronic volume
Is sent to the FM detection / squelch circuit 3 to set an appropriate squelch level.

Description

[Detailed description of the device]     [0001]   [Industrial applications]   This invention relates to a squelch circuit, and enables particularly simple squelch level setting. Squelch circuit.     [0002]   [Prior Art]   Output of noise signal from speaker when receiving low level signal during communication in radio In order to prevent this, the output is prohibited when a received signal below a certain level is received. Such a squelch circuit is widely adopted.   Conventionally, the squelch level setting of the squelch circuit of this type of radio is Installed the volume for setting the rule, and turn the volume manually to set the critical point level. , The title level and SQL open level were set as desired.     [0003]   [Problems to be solved by the device]   As mentioned above, setting the squelch level in the conventional squelch circuit is a manual operation. There is a problem that the adjustment is complicated because it is performed by the work.     [0004]   Therefore, the purpose of this invention is to automatically set the optimum squelch level. To provide a line machine.     [0005]   [Means for Solving the Problems]   In order to solve the above problems, the squelch circuit according to the present invention is   In the squelch circuit where the squelch level is adjusted and set,   Squelch critical point setting switch, squelch tight setting switch and squelch Switch for chi-open setting and electronic volume for adjusting and setting the squelch level And the electronic volume via a process corresponding to the operation of each switch. It is configured to automatically adjust and set the setting level of the system.     [0006]   [Action]   In this device, a squelch critical point setting switch and a squelch tight setting switch are used. Switch and squelch open setting switch depending on the operating state of the squelch level. Improved operability by automatically adjusting and setting the electronic volume for adjusting settings is doing.     [0007]   【Example】   Next, this invention will be described with reference to the drawings.   FIG. 1 is a block diagram showing an example of a wireless device using a squelch circuit according to the present invention. It is a diagram.   During reception, the received signal from the antenna ANT is RF amplified by the RF amplifier 1 and mixed. The IF signal is obtained by frequency conversion by the multiplexer (MIX) 2. I thus obtained The F signal is FM detected / squelched by the FM detection / squelch circuit 3. It is processed and supplied to the AF amplifier 4. The signal amplified by the AF amplifier 4 is It is output as sound from the peaker SP.   From the FM detection / squelch circuit 3, the signal SC indicating squelch ON / OFF is C It is supplied to a PU (Central Processing Unit) 6. The CPU 6 also has a critical point level Setting switch 7, title level setting switch 8 and squelch (SQL) Information signals from the open setting switch 9 are supplied. Adjust the electronic volume 5 to set the squelch level based on the signal SC To do. In this way, a switch indicating the squelch level set by the electronic volume 5 is displayed. The quelch level signal SQ is sent to the FM detection / squelch circuit 3 to obtain a proper squelch. The level is set.     [0008]   FIG. 2 is a flowchart of the processing procedure of the CPU 6 in the embodiment of FIG. Are shown.   First, after the initial setting (step S1), when the key is operated (step S2), It is determined whether or not the switch 8 has been operated (step S3). The squelchtite setting process described below is performed (step S4), and the switch 8 is operated. If not, it is determined whether the switch 9 is operated (step S5). ). Here, if the switch 9 is operated, the squelch open setting process described later is performed. Is performed (step S6), and the switch 7 is operated if the switch 9 is not operated. It is determined whether or not it is operated (step S7). Switch 7 is operated If so, the squelch critical point automatic setting process described later is performed (step S8), and the switch 7 If it has not been operated, another process is performed (step S9).     [0009]   As shown in FIG. 3, the squelchite setting process in step S4 is performed as shown in FIG. Set 0H to the volume 5 (step S41) and output the data (step S41). S42). The squelch open setting process in step S6 is performed as shown in FIG. First, the electronic volume 5 is set to 1FH (step S61), and then the electronic volume is adjusted. The data is output to the tune 5 (step S62).   In the squelch critical point automatic setting process in step S8, first, the electronic volume is set. After setting 1FH to 5 (step S81) and outputting data to the electronic volume 5, (Step S82), for example, waiting for a fixed time of 25 msec (step S83) After that, it is determined whether the squelch signal SC is "0" (step S84). Su In step S84, if SC = 0, the process ends, and if SC = 0, the power is turned off. It is determined whether or not the child volume 5 is 0H (step S85). Step S If it is 0H at 85, the processing is terminated, and if it is not 0H, the electronic volume level is set to 1 Only (step S86), and the process returns to step S82. In addition, The process of decreasing the electronic volume level by 1 in step S86 is shown in the program table. It is current and the level is actually incremented.     [0010]   As described above, the CPU 6 determines whether the switches 7 to 9 are pressed (operated). The process corresponding to the pressed switch is constantly monitored and shown in FIGS. Do so.   That is, the switch 7 is pressed to set the squelch (SQL) critical point. Then, the program jumps to the SQL critical point setting routine in the CPU 6, and the electronic volume Set the lowest volume value (1HF) in the data buffer for the system (step S 81), and output the data to the electronic volume (step S82). And 25 After putting a wait of msec (step S83), the H / L of the SC signal is judged. , Squelch is opened or closed (step S84). SC = 0 If so, the squelch is open, so raise the electronic volume by one step (step S 86, S82). Such processing is repeated until SC = 0. SC = 0 The point at which the squelch point is reached becomes the critical point level.     [0011]   To set the squelch to a tight level, use the electronic volume from the CPU6. The maximum volume data is output to No. 5 (see FIG. 3).   Furthermore, to set the squelch to open, set the electronic volume 5 from the CPU 6 The data with the smallest volume is output (see FIG. 4).     [0012]   In the above-described embodiment, since the squelch setting can be performed using the microcomputer, the automatic meter When combined with a measurement system, squelch level can be automatically set. Also, set not only squelch critical point, tight, open, but also any desired One-touch setting for the level is also possible. In addition, write the frequency to the memory channel If so, store the appropriate squelch level at that frequency along with the frequency. Both are possible.     [0013]   [Effect of the device]   As explained above, the squelch circuit according to the present invention also has a squelch critical point. It can be done by touch, eliminating the need for manual adjustment as in the past and greatly improving operability. To be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration block diagram showing an embodiment of a squelch circuit according to the present invention. FIG. 2 is a flow chart showing an operation processing procedure in the embodiment of FIG. FIG. 3 is a flowchart showing a squelchtite setting processing procedure of the operation processing procedure of FIG. 2; FIG. 4 is a flowchart showing a squelch open setting processing procedure of the operation processing procedure of FIG. 2; 5 is a flowchart showing a squelch critical point automatic setting processing procedure of the operation processing procedure of FIG. 2; [Explanation of reference symbols] 1 RF amplifier 2 Mixer 3 FM detection / squelch circuit 4 AF amplifier 5 Squelch electronic volume (SQL) 6 CPU 7 Squelch critical point setting switch 8 Tight setting switch 9 Squelch open setting switch

Claims (1)

[Claims for utility model registration] In a squelch circuit where the squelch level is adjusted and set, a squelch critical point setting switch, a squelch tight setting switch, and a squelch open setting switch, and an electronic volume for adjusting and setting the squelch level And a squelch circuit which automatically adjusts and sets a setting level of the electronic volume through a corresponding process according to an operation of each switch.