JP7232064B2 - FM relay transmitter - Google Patents

Description

TECHNICAL FIELD The present invention relates to an FM relay transmitter, and in particular, an FM relay transmitter capable of performing start-up confirmation (inspection) work of the device even when FM (Frequency Modulation) broadcasting from a master station is suspended. Regarding.

[FM relay transmitter: Fig. 4]
The configuration of the FM relay transmitter will be described with reference to FIG. FIG. 4 is a schematic diagram of the configuration of an FM relay transmitter.
As shown in FIG. 4, the FM relay transmitter includes an input filter 1, a No. 1 FM relay transmitter 2, a No. 2 FM relay transmitter 3, a switching controller 4, an output filter 5, and a pseudo antenna 6. and
In other words, the FM relay transmitter shown in FIG.

The input filter 1 includes an input band-pass filter (BPF) and a 2-way divider. The FM reception input signal is passed through a specific band by the input BPF, and the FM signal in that band is passed through the 2-way divider. The signal is divided into two and output to No. 1 FM relay transmitter 2 and No. 2 FM relay transmitter 3 .

The No. 1 FM relay transmitter 2 and No. 2 FM relay transmitter 3 internally convert the FM signal distributed from the input filter 1 to an intermediate frequency (IF) and then convert it to an FM signal for relay. output to the switching controller 4.

The switching controller 4 outputs one of the FM signals from the No. 1 FM relay transmitter 2 or the No. 2 FM relay transmitter 3 (working machine) to the output filter 5 and outputs the other (standby machine) to the pseudo antenna 6. control so that
FIG. 4 shows an example in which the FM signal from No. 1 FM relay transmitter 2 is output to output filter 5 and the FM signal from No. 2 FM relay transmitter 3 is output to pseudo antenna 6 .
In the switching controller 4, switching is performed according to the monitor signal from the two FM relay transmitters 2 and 3 and the operation from the outside.

The output filter 5 has an output BPF, allows the FM signal from the switching controller 4 to pass through a specific band, and outputs the FM signal to the outside as an FM transmission output.
A pseudo antenna 6 is a dummy antenna.

[Configuration related to conventional switching control: FIG. 5]
Next, a configuration related to conventional switching control will be described with reference to FIG. FIG. 5 is a configuration block diagram relating to conventional switching control.
As shown in FIG. 5, the configuration related to conventional switching control includes a No. 1 FM relay transmitter 2', a No. 2 FM relay transmitter 3', and a switching controller 4'.

The No. 1 FM relay transmitter 2' receives the FM signal, detects the input of the FM signal, and outputs whether or not the FM input is detected to the switching controller 4'. The No. 2 FM relay transmitter 3' performs the same operation.
When FM input detection presence/absence is input from No. 1 FM relay transmitter 2' and No. 2 FM relay transmitter 3', the switching controller 4' switches to the FM relay transmitter without FM input detection. Outputs an AMP OFF control signal.

The FM relay transmitter that receives the AMP OFF control signal forcibly turns off the AMP (amplifier) of the FM relay transmitter.
Further, both of the two FM relay transmitters perform AMP OFF control for the FM relay transmitter connected to the pseudo antenna 6 when there is no FM input detection or when standby is selected.
Specific control within the FM relay transmitter will be described later.

[Internal circuit of conventional repeater transmitter: Fig. 6]
Next, an internal circuit of a conventional FM relay transmitter (relay transmitter) will be described with reference to FIG. FIG. 6 is an internal circuit diagram of a conventional repeater transmitter.
As shown in FIG. 6, the internal circuit diagram of a conventional repeater transmitter 2' includes a reception conversion circuit (RX) 21, a voltage comparator 22, an IF circuit connection relay (RL) 23, a transistor 24, and a transmission circuit. A conversion circuit (TX) 25 , a multistage amplifier circuit (AMP) 26 , a connection switch 27 , an FM input detection switch (SW) 28 and a power control circuit (PWR CONT) 29 are provided.

The operation of the internal circuit diagram of the conventional repeater transmitter 2' will be described.
First, a case where an FM signal is input to the relay transmitter 2' will be described.
When the FM signal is input to the repeater transmitter 2', it is converted to an intermediate frequency (IF) signal by the reception conversion circuit 21 and output to the connection switch 27, and the reception level voltage is output to the voltage comparator 22. .

The voltage comparator 22 compares the squelch level voltage connected to the "-" terminal with the reception level voltage connected to the "+" terminal. Then the reception level voltage becomes High (H). The output is input to the FM input detection switch 28, and the presence or absence of FM input detection is output to the switching controller 4'. Since the signal from the voltage comparator 22 is "H", the presence of FM input detection (CLOSE) is output.

Also, the output from the voltage comparator 22 is input to the base of the transistor 24, and the base input becomes H (FM input detection: present), so the transistor 24 is turned on and current flows through the IF circuit connection relay 23. The connection switch 27 is turned on (connected).
The transmission conversion circuit 25 receives the IF signal from the reception conversion circuit 21, converts it to an FM signal, and outputs the FM signal to the multistage amplifier circuit 26. The multistage amplifier circuit 26 outputs the amplified FM signal.

Next, the case where there is no FM signal input to the relay transmitter 2' will be described.
When there is no input of the FM signal to the reception conversion circuit 21, the voltage comparator 22 has the reception level voltage lower than the squelch level voltage, and the output voltage becomes "L".
Then, no FM input is detected, and no (OPEN) is output to the switching controller 4'.

Also, since the output voltage from the voltage comparator 22 becomes "L", the transistor 24 is turned off, no current flows through the IF circuit connection relay 23 and it does not operate, and the connection switch 27 is turned off (disconnected). Therefore, the IF signal is not input to the transmission conversion circuit 25 and is not FM-output from the multistage amplifier circuit 26 .

Further, when an AMP OFF control signal is input from the switching controller 4' to the power control circuit 29 of the relay transmitter 2' and a "CLOSE" control signal for turning off the power of the multi-stage amplifier circuit 26 is input, the power control circuit 29 turns off the power of the multistage amplifier circuit 26 .
Further, when the control signal “OPEN” for turning on the power of the multistage amplifier circuit 26 is input, the power supply control circuit 29 turns on the power of the multistage amplifier circuit 26 .
As for the AMP OFF control signal, "CLOSE" or "OPEN" is selected by a push button provided on the switching controller 4'.

[Logic system of conventional switching controller: FIG. 7]
Next, the logic system of a conventional switching controller will be described with reference to FIG. FIG. 7 is a logical system diagram of a conventional switching controller.
As shown in FIG. 7, the switching controller 4' receives FM input detection signals from the No. 1 FM relay transmitter and the No. 2 FM relay transmitter. FIG. 7 illustrates a case where no FM input detection (OPEN) is input.

In the case of No. 1 reception (no FM input detected from No. 1 repeater transmitter) and No. 2 reception no (no FM input detected from No. 2 repeater transmitter), the "H" signal is the inverted logical sum (inverted OR) input to the circuit 41 .
The output of the inverting OR circuit 41 is "L" when both inputs are "H", and the output is "H" for other inputs.

Also, when the No. 1 relay transmitter is connected to the FM output antenna (No. 1 antenna), it outputs "H", and when it is not connected, it outputs "L".
Also, when the No. 2 relay transmitter is connected to the FM output antenna (No. 2 antenna), it outputs "H", and when it is not connected, it outputs "L".
Normally, either No. 1 antenna or No. 2 antenna is connected.

Further, when standby is selected by a switch for turning on/off the AMP 26 of the standby relay transmitter provided in the switching controller 4', an "H" signal is output. This "H" turns on the AMP 26 of the standby repeater transmitter. Standby off "L" turns off the AMP 26 of the relay transmitter that is on standby.

The output of the inverting OR circuit 41 becomes "L" when both the signal 1 is not received and the signal 2 is not received. , output a broadcast pause after ten seconds (10 sec).
Therefore, if there is an FM input signal in either the No. 1 relay transmitter or the No. 2 relay transmitter, the broadcast will not be suspended.
Outputs from the inverted OR circuit 41 are also input to logical product (AND) circuits 42 , 43 , 44 and 45 .

The outputs of the AND circuits 42 to 45 are "L" when the output from the inverted OR circuit 41 is "L" (both when No. 1 is not received and No. 2 is not received). In this state, the outputs from the exclusive OR (exclusive OR) circuits 46 and 47 are "H", and "CLOSE" (AMP OFF/No. 1 AMP OFF) is transmitted to No. 1 relay transmitter, and No. 2 relay transmission is performed. Output “CLOSE” (AMP OFF/No.2 AMP OFF) to the aircraft.

When the output of the inverting OR circuit 41 is "H" (when No. 1 reception is present, or No. 2 reception is present, or both are present), the No. 1 antenna is connected and the No. 2 antenna is not connected. "L" and the standby state is "H", the outputs of AND circuits 42 and 45 become "H", the outputs of AND circuits 43 and 44 become "L", and the outputs of exclusive OR circuits 46 and 47 become "H". becomes "L", and the power of the AMP 26 of neither the No. 1 relay transmitter nor the No. 2 relay transmitter is turned off.
When the output of the inverting OR circuit 41 is "H", the output is "H" when the No. 2 antenna is connected, and "L" when the No. 1 antenna is not connected, and the standby state is "H", the same result as above is obtained. .

In addition, when the output of the inverting OR circuit 41 is "H", the output of the AND circuit 42 is "H" when the No. 1 antenna is connected, "L" when the No. 2 antenna is not connected, and the standby is "L". "H", the outputs of the other AND circuits 43 to 45 are "L", the output of the exclusive OR circuit 46 is "L", the output of the exclusive OR circuit 47 is "H", and the output for FM output is "L". Turn off the AMP 26 of the No. 2 repeater transmitter that is not connected to the antenna.

In addition, when the output of the inverting OR circuit 41 is "H", the output of the AND circuit 44 is "H" when the No. 2 antenna is connected, "L" when the No. 1 antenna is not connected, and the standby is "L". The outputs of the other AND circuits 42, 43 and 45 are "L", the output of the exclusive OR circuit 47 is "L", the output of the exclusive OR circuit 46 is "H", and the FM output is "H". Turn off the AMP 26 of the No. 1 repeater transmitter that is not connected to the antenna for

[Related technology]
In addition, as related prior art, JP-A-2015-053662 "Wireless relay device setting method" (Patent document 1), JP-A-2008-177804 "Switching control device" (Patent document 2), JP-A-2005 -210299 "Radio Relay System" (Patent Document 3).

Japanese Patent Laid-Open No. 2002-200000 discloses that various settings are performed from a wireless communication terminal for management using a downlink frequency of a wireless relay device.
Japanese Patent Laid-Open No. 2002-200000 discloses that when a transmitter used for relaying fails, switching control of a signal transmission path is performed without interrupting broadcasting.
Patent Literature 3 discloses that a mode switching switch is provided at the output of the high-frequency reception section to switch between a digital reception control section and an analog reception control section.

JP 2015-053662 A JP 2008-177804 A Japanese Patent Application Laid-Open No. 2005-210299

However, in the conventional FM relay transmitter, when there is no FM input to the relay transmitter, the relay transmitter cannot be activated, and FM relay transmission is performed during the time period when FM broadcasting from the master station is suspended. There was a problem that it was not possible to check (inspect) the start-up of the device.

Incidentally, Patent Literatures 1 to 3 do not describe a configuration for performing activation confirmation (inspection) work for an FM relay transmission device during a period in which FM broadcasting from a master station is suspended.

The present invention has been made in view of the above-mentioned circumstances, and when FM broadcasting is suspended, only relay transmitters connected to pseudo antennas are activated, and activation confirmation (inspection) of FM relay transmitters is carried out. An object of the present invention is to provide an FM relay transmitter capable of performing

The present invention for solving the problems of the conventional example is an FM relay transmission apparatus having a plurality of relay radios and a switching controller for performing switching control of the plurality of relay radios, wherein the switching controller is , When FM broadcasting is suspended, output a forced connection instruction of the intermediate frequency circuit to the relay radio connected to the pseudo antenna among the plurality of relay radios, and input the forced connection instruction. A repeater radio device forcibly connects an intermediate frequency circuit.

The present invention is characterized in that, in the FM relay transmitting apparatus, the relay radio unit that inputs the forced connection instruction cancels the power-off of the amplifier.

The present invention is characterized in that, in the FM relay transmitting apparatus described above, standby is set when the switching controller outputs an instruction for forced connection of the intermediate frequency circuit.

The present invention is characterized in that, in the FM relay transmitting apparatus described above, the relay radio apparatus performs forced connection by forcibly operating the connection relay of the intermediate frequency circuit.

According to the present invention, the switching controller instructs the relay radio connected to the pseudo antenna among the plurality of relay radios to forcibly connect the intermediate frequency circuit when the FM broadcasting is suspended. , and the relay radio to which the forced connection instruction is input is the FM relay transmitter that performs the forced connection of the intermediate frequency circuit. There is an effect that the start-up confirmation (inspection) work of the FM relay transmitting device can be performed during the time period when the FM broadcasting is suspended.

FIG. 3 is a configuration block diagram relating to switching control of this device; It is an internal circuit diagram of the relay transmitter of this apparatus. It is a logical system diagram of the switching controller of this apparatus. 1 is a schematic diagram of the configuration of an FM relay transmitter; FIG. FIG. 10 is a configuration block diagram related to conventional switching control; 1 is an internal circuit diagram of a conventional relay transmitter; FIG. It is a logical system diagram of the conventional switching controller.

An embodiment of the present invention will be described with reference to the drawings.
[Outline of Embodiment]
The FM relay transmitting device (this device) according to the embodiment of the present invention prevents FM signals out of specification from the output terminal of the FM relay transmitting device to the transmitting antenna when FM broadcasting from the master station is suspended. Output is disabled and only the relay transmitter connected to the pseudo antenna is activated, so that the activation confirmation (inspection) work of the FM relay transmitter during the period when the FM broadcast from the master station is suspended. can be performed.

[This device]
Although this apparatus basically has the configuration shown in FIG. 4, the specific configurations of the switching controller 4 and the FM relay transmitters 2 and 3 are different from the conventional configuration.

[Configuration related to switching control of this device: Fig. 1]
Next, a configuration related to switching control of this device will be described with reference to FIG. FIG. 1 is a configuration block diagram relating to switching control of this device.
As shown in FIG. 1, the configuration related to switching control of this apparatus includes a No. 1 FM relay transmitter 2, a No. 2 FM relay transmitter 3, and a switching controller 4. FIG.

Here, a control line (a control line for transmitting an instruction for forcibly connecting an IF circuit, which will be described later) is added between the two relay transmitter units (within the equipment rack) from the switching controller 4, and two systems are added one by one. do. However, if wiring (one unused line for each two systems) is already connected to the free terminal of the D-sub connector of the control line (bundled line) of each system, there is no need to add a control line between units. is.

The No. 1 FM relay transmitter 2 receives the FM signal, detects the input of the FM signal, and outputs to the switching controller 4 whether or not the FM input is detected. The No. 2 FM relay transmitter 3 performs the same operation.
When the switch controller 4 is simultaneously input with no FM input detection from the No. 1 FM relay transmitter 2 and the No. 2 FM relay transmitter 3, the No. 1 FM relay transmitter 2 and the No. 2 FM relay transmitter 3 AMP OFF control signal is output.
The FM relay transmitter to which the AMP OFF control signal is input forcibly turns off the AMP (amplifier) of the FM relay transmitter.

Further, the switching controller 4 uses the control lines added to the No. 1 FM relay transmitter 2 and the No. 2 FM relay transmitter 3 to output an IF circuit forced connection instruction.
When the FM relay transmitter receives an instruction to forcefully connect the IF circuit, it operates the relay (IF circuit connection relay and connection switch) that cuts off the IF circuit, and regardless of whether the AMP is activated or stopped, the relay transmitter will Outputs an FM signal that is out of specification.

[Internal circuit of relay transmitter of this device: Fig. 2]
Next, the internal circuit of the FM relay transmitter (relay transmitter) of this device will be described with reference to FIG. FIG. 2 is an internal circuit diagram of the repeater transmitter of this device.
As shown in FIG. 2, the internal circuit diagram of the relay transmitter 2 of this lawsuit includes a reception conversion circuit (RX) 21, a voltage comparator 22, an IF circuit connection relay (RL) 23, a transistor 24, and a transmission conversion circuit. It has a circuit (TX) 25 , a multistage amplifier circuit (AMP) 26 , a connection switch 27 , an FM input detection switch (SW) 28 and a power supply control circuit (PWR CONT) 29 .

Then, wiring is added to the rear surface of the D-sub connector inside the two relay transmitters, and a terminal for control contact input "IF circuit forced connection" is added.
Specifically, one wiring is connected to the point a on the collector side of the transistor 24, the other wiring is connected to the point b on the emitter side of the transistor 24, and the two wirings are connected to the IF circuit forced connection terminal.

If the "H" voltage is not input to the base of the transistor 24, the transistor 24 will not turn on, the IF line connection relay 23 will not operate, and the selector switch 27 will remain unconnected.
However, when the IF circuit forced connection terminal is used to forcibly connect the point a on the collector side and the point b on the emitter side of the transistor 24 in response to an IF circuit forced connection instruction from the switching controller 4, current is allowed to flow. The IF line connection relay 23 is activated, and the changeover switch 27 is in the connected state.
As a result, even if there is no FM signal, the IF signal from the reception conversion circuit 21 can be output to the AMP 26 via the transmission conversion circuit 25, amplified by the AMP 26, and output as an FM signal.

The operation of the internal circuit diagram of the relay transmitter 2 of this device will be described.
First, the case where the relay transmitter 2 receives an FM signal will be described.
When the FM signal is input to the relay transmitter 2 , it is converted to an intermediate frequency (IF) signal by the reception conversion circuit 21 and output to the connection switch 27 , and the reception level voltage is output to the voltage comparator 22 .

The voltage comparator 22 compares the squelch level voltage connected to the "-" terminal with the reception level voltage connected to the "+" terminal. Then the reception level voltage becomes High (H). The output is input to the FM input detection switch 28 to output to the switching controller 4 whether or not the FM input is detected. Since the signal from the voltage comparator 22 is "H", the presence of FM input detection (CLOSE) is output.

Also, the output from the voltage comparator 22 is input to the base of the transistor 24, and since the base input is H (FM input detection: present), the transistor 24 is turned on, and current flows through the IF circuit connection relay 23. The connection switch 27 is turned on (connected).
Further, one wiring of the IF circuit forced connection terminal is connected to the point a on the collector side of the transistor 24, and the other wiring of the IF circuit forced connection terminal is connected to the point b on the emitter side of the transistor 24. FIG. By connecting the points a and b with the IF circuit forced connection terminal, the IF circuit connection relay 23 is forced to operate.
The transmission conversion circuit 25 receives the IF signal from the reception conversion circuit 21, converts it into an FM signal, and outputs it to the AMP 26, which outputs the amplified FM signal.

Next, a case where no FM signal is input to the relay transmitter 2 will be described.
When there is no input of the FM signal to the reception conversion circuit 21, the voltage comparator 22 has the reception level voltage lower than the squelch level voltage, and the output voltage becomes "L".
Then, no FM input is detected, and no (OPEN) is output to the switching controller 4 .

Also, since the output voltage from the voltage comparator 22 becomes "L", the transistor 24 is turned off, current does not flow to the IF circuit connection relay 23 and does not operate, and the connection switch 27 is turned off (disconnected). Therefore, the IF signal is not input to the transmission conversion circuit 25 and is not FM-output from the AMP 26 .

However, when the IF circuit forced connection instruction is received from the switching controller 4 to the IF circuit forced connection terminal, the point a on the collector side of the transistor 24 and the point b on the emitter side are forcibly connected so that there is no FM input. Nevertheless, the IF line connection relay 23 can be operated and the connection switch 27 can be connected.

Further, when the AMP OFF control signal is input from the switching controller 4 to the power control circuit 29 of the relay transmitter 2 and the control signal "CLOSE" for turning off the power of the AMP 26 is input, the power control circuit 29 turns off the power of the AMP 26. Power off.
Further, when the control signal "OPEN" for turning on the power of the AMP 26 is input, the power control circuit 29 turns on the power of the AMP 26 .
As for the AMP OFF control signal, "CLOSE" or "OPEN" is selected by a push button provided on the switching controller 4. FIG.

[Logic system of switching controller of this device: Fig. 3]
Next, the logic system of the switching controller of this device will be described with reference to FIG. FIG. 3 is a logical system diagram of the switching controller of this device.
In the switching controller 4, as shown in FIG. 3, FM input detection signals are input from the No. 1 relay transmitter and the No. 2 FM relay transmitter. FIG. 3 illustrates the case where FM input detection not detected (OPEN) is input.

In the case of No. 1 reception (no FM input detected from No. 1 repeater transmitter) and No. 2 reception no (no FM input detected from No. 2 repeater transmitter), the "H" signal is the inverted logical sum (inverted OR) input to the circuit 41 .
The output of the inverting OR circuit 41 is "L" when both inputs are "H", and the output is "H" for other inputs.

Also, when the No. 1 relay transmitter is connected to the FM output antenna (No. 1 antenna), it outputs "H", and when it is not connected, it outputs "L".
Also, when the No. 2 relay transmitter is connected to the FM output antenna (No. 2 antenna), it outputs "H", and when it is not connected, it outputs "L".
Normally, either No. 1 antenna or No. 2 antenna is connected.

Further, when standby is selected by a switch provided in the switching controller 4 for turning on/off the AMP 26 of the standby relay transmitter, an "H" signal is output. This "H" turns on the AMP 26 of the standby repeater transmitter. Standby off "L" turns off the AMP 26 of the relay transmitter that is on standby.

The output of the inverting OR circuit 41 becomes "L" when both the signal 1 is not received and the signal 2 is not received. , output a broadcast pause after ten seconds (10 sec).
Therefore, if there is an FM input signal in either the No. 1 relay transmitter or the No. 2 relay transmitter, the broadcast will not be suspended.

As a feature of this device, logical product circuits (AND) 51 to 54 are newly provided.
The AND circuit 51 receives a signal indicating that the No. 2 antenna is being connected (the No. 2 FM relay transmitter is being connected to the antenna), a standby signal, and a signal from the on-delay timer 49 . When all of these signals are "H", an instruction for forcibly connecting the IF circuit is output to the No. 1 relay transmitter.
The AND circuit 52 receives the signal indicating that the No. 1 antenna is being connected (the No. 1 FM relay transmitter is being connected to the antenna), the standby signal, and the signal from the on-delay timer 49 . When all of these signals are "H", an instruction for forcibly connecting the IF circuit is output to the No. 2 repeater transmitter.

The AND circuit 53 receives a signal indicating that the No. 2 antenna is being connected, a signal indicating that the antenna is on standby, and a signal from the on-delay timer 49 . "H" is output to the exclusive OR circuit 46 when all of these signals are "H".
The AND circuit 54 receives a signal indicating that antenna No. 1 is being connected, a signal indicating that the antenna is on standby, and a signal from the on-delay timer 49 . "H" is output to the exclusive OR circuit 47 when all of these signals are "H".

Outputs from the inverted OR circuit 41 are also input to logical product (AND) circuits 42 , 43 , 44 and 45 .
The outputs of the AND circuits 42 to 45 are "L" when the output from the inverted OR circuit 41 is "L" (both when No. 1 is not received and No. 2 is not received).
The output of the AND circuit 53 is "H" when the No. 2 antenna is connected "H" and the standby state is "H", otherwise the output is "L". The output of the AND circuit 54 is "H" when the No. 1 antenna is connected "H" and the standby state is "H", otherwise the output is "L".

In this state (during broadcast suspension determination), the exclusive OR (exclusive OR) circuit 46 indicates that the No. 2 antenna is connected (the No. 2 FM relay transmitter is connected to the antenna) "H" and the No. 1 antenna dummy is connected. (The No. 1 FM relay transmitter is connected to a dummy antenna.) In the state of "L" and standby and "H" (broadcasting is suspended), the output becomes "L" and the No. 1 relay transmitter is "OPEN" (AMP ON). / No. 1 AMP ON). In other words, when the No. 1 antenna is connected and it enters standby mode, the AMP 26 of the No. 1 relay transmitter connected to the dummy antenna is not powered off.
In addition, the exclusive OR circuit 47 indicates that the No. 1 antenna is connected (the No. 1 FM relay transmitter is connected to the antenna) "H" and the No. 2 antenna dummy is connected (the No. 2 FM relay transmitter is connected to the dummy antenna) " In the state of "L" and standby on "H", the output becomes "L" and outputs "OPEN" (AMP ON/No. 2 AMP ON) to No. 2 relay transmitter. In other words, when the No. 2 antenna is connected and in standby mode, the power of the AMP 26 of the No. 2 relay transmitter connected to the dummy antenna is not turned off.

When the output of the inverting OR circuit 41 is "H" (when No. 1 reception is present, or No. 2 reception is present, or both are present), the No. 1 antenna is connected and the No. 2 antenna is not connected. "L" and the standby state is "H", the outputs of the AND circuits 42 and 45 become "H", the outputs of the AND circuits 43, 44, 53 and 54 become "L", and the exclusive OR circuit 46 , 47 become "L", and the AMP 26 of neither the No. 1 relay transmitter nor the No. 2 relay transmitter is turned off.
When the output of the inverting OR circuit 41 is "H", the output is "H" when the No. 2 antenna is connected, and "L" when the No. 1 antenna is not connected, and the standby state is "H", the same result as above is obtained. .

In addition, when the output of the inverting OR circuit 41 is "H", the output of the AND circuit 42 is "H" when the No. 1 antenna is connected, "L" when the No. 2 antenna is not connected, and the standby is "L". "H", the outputs of the other AND circuits 43 to 45, 53, 54 are "L", the output of the exclusive OR circuit 46 is "L", the output of the exclusive OR circuit 47 is "H", Turn off the AMP 26 of the No. 2 repeater transmitter that is not connected to the FM output antenna.

In addition, when the output of the inverting OR circuit 41 is "H", the output of the AND circuit 44 is "H" when the No. 2 antenna is connected, "L" when the No. 1 antenna is not connected, and the standby is "L". The outputs of the other AND circuits 42, 43, 45, 53 and 54 are "L", the output of the exclusive OR circuit 47 is "L", and the output of the exclusive OR circuit 46 is "H". Then, the AMP 26 of the No. 1 relay transmitter that is not connected to the FM output antenna is turned off.

As shown in FIG. 3, in the processing of the logic system of the switching controller 4, the relay transmitter connected to the transmission antenna is not controlled for forced connection of the IF circuit when the broadcasting is suspended, and the AMP OFF is performed. IF circuit forced connection control is performed and AMP OFF control is canceled only when standby is selected for the relay transmitter connected to the pseudo antenna 6 when broadcasting is suspended.

[Effects of Embodiment]
According to this device, the switching controller 4 outputs an instruction for forced connection of the IF circuit to the No. 1 relay transmitter 2 and the No. 2 relay transmitter 3, and the transmission antenna is connected during the suspension of broadcasting of the master station. To facilitate activation confirmation (inspection) work of an FM relay transmitter by activating a relay transmitter connected to a pseudo antenna 6 only when standby is selected while cutting off an IF circuit of the relay transmitter. There is an effect that can be done.

The present invention provides an FM relay transmitter capable of activating only relay transmitters connected to a pseudo antenna and performing activation confirmation (inspection) work of the FM relay transmitter when FM broadcasting is suspended. preferred.

DESCRIPTION OF SYMBOLS 1... Input filter 2, 2'... No. 1 FM relay transmitter 3, 3'... No. 2 FM relay transmitter 4, 4'... Switching controller 5... Output filter 6... Pseudo antenna 21... Reception conversion circuit (RX) 22 Voltage comparator 23 IF circuit connection relay (RL) 24 Transistor 25 Transmission conversion circuit (TX) 26 Multistage amplifier circuit (AMP) 27 Connection switch 28...FM input detection switch (SW), 29...Power supply control circuit (PWR CONT), 41...Inverted OR circuit (inverted OR circuit), 42 to 45, 51 to 54...AND circuit, 46, 47...Exclusive logic sum circuit (exclusive OR circuit), 48... inverting circuit, 49... on-delay timer

Claims (4)

An FM relay transmitter having a plurality of relay radios and a switching controller that performs switching control of the plurality of relay radios,
said switching controller outputs an instruction for forced connection of an intermediate frequency circuit to a relay radio connected to a pseudo antenna among said plurality of relay radios when FM broadcasting is suspended ;
An FM repeater transmitting apparatus, wherein the relay radio having received the command for forced connection performs forced connection of the intermediate frequency circuit. 2. The FM repeater transmitter according to claim 1, wherein the repeater radio that has input the command for forced connection cancels power-off of the amplifier. 3. The FM repeater transmitter according to claim 1, wherein the switching controller is set to standby when outputting an instruction for forced connection of the intermediate frequency circuit. 4. The FM repeater transmission apparatus according to claim 1, wherein the repeater radio performs forced connection by forcibly operating a connection relay of the intermediate frequency circuit.

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