2009年11月15日 · VOX is a voice controlled switch, used often for microphones replacing the classic switching button. The actuating threshold is set thru the volume potentiometer of the amplifier which command the VOX circuit. The VOX switching threshold is 600mV ( on R2 ) and the maximum input voltage must not be higher than 40Vpp. VOX circuit diagram

The figure below show us a basic VOX circuit which will perform very well once the VOX level is set correctly. This is a very low cost circuit and you can find all parts at your local Radio Shack store.

2008年5月21日 · VOX is a switch ordered by voice, often used at microphones instead of the classic switch button. The vox described here may be connected to almost any type of audio equipment which has an external speaker for coupling. The threshold action is set with volume potentiometer of the audio amplifier which commands the VOX .

2024年3月29日 · 阈值动作由音频 放大器的音量 电位器设置，该电平放大器命令vox。 来自R2 端子的 信号（在免提电话上）在T1基座上 电容连接。 电阻R3限制 晶体管的基极 电流，在电压输入超过600mV的情况下。

2017年2月25日 · I want to build a simple circuit, preferably only a few transistors which simply activates when it hears a low level audio, and deactivates when the audio signal does not exist anymore. No pre-delay and no after delay is needed or wanted.

In this case, a simple VOX circuit can be used for PTT instead. It detects the digital-mode tones from the USB sound card output and then activates the rig's PTT line, causing transmission of tones when they are present. It is powered by the 5v supply from the USB port. It uses an opto-coupler to provide PTT isolation.

This schematic diagram below show a circuit of VOX Box (voice-operated switch). This circuit consist of a Schmitt trigger, a relay driver, and microphone preamplifier. The microphone preamplifier(U1) receive input signal which will be amplified.

The anti-vox circuit reduces gain of the vox path when audio is detected at the speaker. This will suppress the chances of vox being triggered when the station is listening to an incoming audio. That also implies one issue - the station cannot transmit when audio is present at the receive path. Line up procedures. The circuit should function ...

Here is a 3 transistors 6 diodes circuit that is a Voice Operated Tx PTT control as well as an ANTI VOX circuit to stop mis-operation from Rx noise. HOW IT WORKS

2019年11月23日 · VOX (voice activated transmission) activates the station’s transmission (press PTT) when it detects sound (modulation signal) at the microphone or (if the transceiver has one) at the audio input. This circuit is useful when, say, you drive (car or motorcycle) and you can’t use a hand to press PTT to talk.