Four-way hotline coupler TH-401, dedicated to recording studios and radio stations

Welcome to consult
※Product performance
This product is a professional hotline coupler developed by our company. It is specially used by various radio stations and TV stations in live broadcast programs, and is also suitable for telephone conferences. , telephone recording and other occasions.
Provides four-way telephone access, using microcomputer chip and electronic switch technology. Each channel is controlled independently of each other. The in and out operations are convenient and flexible. It can realize four-way telephone access at the same time, and the communication between listeners and hosts, listeners and listeners The room can be set up for multi-party calls and free conversations, or it can be put on hold for separate conversations.
Provides audio and control interfaces for the main and backup live broadcast rooms. Users only need to add a control box and corresponding control cables to achieve time-sharing sharing of a hotline device between the two live broadcast rooms.
Each channel is equipped with a side sound elimination adjustment switch, which can obtain better phone sound quality and avoid harmful sound feedback.
There are built-in call devices in the director and host control boxes, including microphones and speakers (the host can switch the call output to the mixer or headphone distributor and has a call button, making internal calls very convenient. Convenient.
The non-guided function can be used when there is only one host. Just turn on the non-guided switch on the front panel of the host (the indicator light goes out at this time)
※Technical indicators
Audio Input (from the live broadcast room) balanced core plug
Audio output (to the live broadcast room) balanced core plug
(mixed output) unbalanced core plug
(headphones) three-core plug
( Intercom output) Unbalanced core plug
Frequency response
Distortion
Signal-to-noise ratio (excluding telephone line noise)
Side tone suppression
Host size standard chassis
Power consumption
Structural diagram
The structure of the host and control box is shown in the figure and figure
The main unit structural diagram
Headphone jack
Headphone level adjustment knob
Sending signal size adjustment button to the telephone line
Live room and live room selection indication and live room and live room selection switch
Power switch
Power socket (fuse)
Control cable interface
Audio input and output interface
Telephone outside line and telephone interface
If there is no director selection switch, the light is on when there is a director (the switch is to the left and the light is off when it is not on the director (the switch is on the right))
Installation and debugging
It is recommended to install the host in the director room, answer the outside line and the director’s phone.
Connect the director control box to the control port of the host, and the live broadcast room control box to the control port of the host. (Note The director control box and the live broadcast room control box are the same, except that the control port of the connected host is different)
Connect the audio output (and) of the host to a certain line input module of the live mixer (balanced connection method , if the mixer has an unbalanced input, please leave the middle ring of the microphone plug connected to the host floating, and the host audio input ( and ) must be taken from the auxiliary output of the live mixer (at the same time, the corresponding hotline input module of the live mixer should be Adjust the auxiliary control volume to (minimum) to avoid harmful sound feedback. The mixed output ( ) can be used to connect to a power amplifier for monitoring in the studio.
Sound cancellation debugging
Side sound cancellation adjustment switch and potentiometer position Figure
Before official use, the tone must be eliminated. The audio test signal (working level) is added to the hotline device through the line input, and the line output ( ) of the hotline device is connected to an electronic millivolt meter. A certain line of telephone is connected (see below for the specific operation method). You can see that the millivolt meter has a small reading. Open the case and adjust the corresponding side-sound elimination matching resistor and capacitor of the line as shown in the figure (controlled by the toggle switch, hexadecimal system, As shown in the figure, the left side is the high position and the right side is the low position. The combination makes the millivolt meter reading the smallest. Repeat the debugging and complete the adjustment of other channels.
During the call, the volume will be adjusted to a suitable place so that the hotline listeners can hear the volume at a moderate level.
Installation and adjustment of intercom
After the director control box and live broadcast room control box are installed, intercom can be used. How to use it: Press and hold the
button and speak into the microphone, and the other party can hear it. , the speaker volume can be adjusted by inserting a screwdriver into the small hole ( ) on the top for fine adjustment. In the live broadcast room, if the speaker cannot produce sound, you can insert a core plug (mono channel) on the rear panel to guide the speaker signal to the mixer or headphone distributor, and use the headphones Monitoring.
Operation method
● Incoming call When a call comes in from a certain channel, the phone on that channel will ring, and the corresponding light-emitting tube on the director control box will flash, indicating that there is an incoming call, and the director can Answer the call on this channel
● Waiting for broadcast When the director answers the call and decides to switch to this channel, just press the button corresponding to this channel on the control box, and the green light will turn on. At this time, the hotline listeners can hear the live program, but temporarily If you are not yet able to participate in the program broadcast and want to exit a certain channel from the standby state, you only need to click once. The green light will go out, which means you will exit the standby state
● The broadcast host will click the corresponding channel according to the instructions of the green light on the live broadcast control box. button, the green light turns to red, and the hotline listeners begin to participate in the program
● Exit: After the call ends, the host presses the button again, the red light turns to flashing green, entering the exit state, reminding the director to cut out the phone, and the director After seeing the flashing green light, press the button of the channel to switch out the phone. The holder can also press and hold the button. After a few seconds, the red light goes out and the phone is automatically switched out
●Multi-party calls enter in a certain channel When broadcasting, switch to one or more channels to realize multi-party calls and discuss issues and other activities. The operation method is the same as the single channel
●Call Hold When the host is talking to a certain listener, if he needs to temporarily interrupt, And answer or make other calls, just put this channel into the exit state temporarily (the flashing green light If you want to resume the call, you can press the button again

Emergency cut out whether it is the director or the host If the person presses the button for more than seconds, the line will be automatically disconnected and cut out
When using the non-director function, turn on the no-director switch on the front panel of the host to use it. When a call comes, the control box of the live broadcast room The corresponding indicator light flashes, and the host can directly press the corresponding button to connect to the audience hotline, and at the same time, he can directly communicate with the audience through the microphone (at this time, the indicator light on the control box is solid red, and the call is hung up during the broadcast state As long as you press the button again, the light goes out to indicate that it is disconnected. (There is an indicator light on the right side of the no-director switch. When the light is on, the no-director function is cancelled. When the light is off, the no-director function is enabled.)
Pay attention to the connection method of the telephone line. Telephone
Answering the outside line
Packing list
● Hotline main unit
● Hotline control box
●Control cable root
●Operation manual This
●Power cord
●Telephone cord