The personal website of Scott W Harden

Puxing 777 Radio Headset Schematic

I successfully created a speaker/microphone/transmit button circuit for the puxing 777 which probably works for all puxing radios. Instead of simply using circuits found on other websites (always for other radios), I decided to reverse-engineering an earphone/microphone headset that came with the radio to determine how it worked. I can't claim that I'm an expert in electronics theory, but I can say that I faithfully rebuilt the circuitry within the factory-shipped headset and it worked. The result allows me to leave my handheld radio in its charger while casually listening/transmitting with a button that I made instead of having to reach around and awkwardly squeeze the transmit button on the side of the radio. Once again, I built this circuit and it was successful for me, but there may still be a better way to do it.

The microphone is a 20-cent electret microphone with no special modifications. The speaker I used is a standard 8ohm loudspeaker with no special modifications. The switch is a keyboard-style (push-to-talk) switch, and the capacitor I used is good for 10nF.

If you have any ideas for improvements, let me know! I'll post some photos once I have my completed little "base station" set up. My ultimate goal is to turn an el-cheapo handheld VHF radio into a decent desktop transceiver by combining it with a nice antenna (located on a balcony at 30ft) and a convenient, easy-to-use switches/buttons/microphone/speaker/etc on a desktop panel.

Markdown source code last modified on January 18th, 2021
---
title: Puxing 777 Radio Headset Schematic
date: 2009-04-22 11:56:42
tags: amateur radio, circuit, old
---

# Puxing 777 Radio Headset Schematic

__I successfully created a speaker/microphone/transmit button circuit for the puxing 777__ which probably works for all puxing radios.  Instead of simply using circuits found on other websites (always for other radios), I decided to reverse-engineering an earphone/microphone headset that came with the radio to determine how it worked. I can't claim that I'm an expert in electronics theory, but I can say that I faithfully rebuilt the circuitry within the factory-shipped headset and it worked.  The result allows me to leave my handheld radio in its charger while casually listening/transmitting with a button that I made instead of having to reach around and awkwardly squeeze the transmit button on the side of the radio.  Once again, I built this circuit and it was successful for me, but there may still be a better way to do it.

<div class="text-center img-border">

[![](puxing_thumb.jpg)](puxing.png)

</div>

The microphone is a 20-cent [electret microphone](http://en.wikipedia.org/wiki/Electret_microphone) with no special modifications.  The speaker I used is a [standard 8ohm loudspeaker](http://en.wikipedia.org/wiki/File:3.5_Inch_Speaker.jpg) with no special modifications.  The switch is a keyboard-style (push-to-talk) switch, and the capacitor I used is good for 10nF.

<div class="text-center img-border">

![](headset.jpg)

</div>

__If you have any ideas for improvements, let me know!__  I'll post some photos once I have my completed little "base station" set up.  My ultimate goal is to turn an el-cheapo handheld VHF radio into a decent desktop transceiver by combining it with a nice antenna (located on a balcony at 30ft) and a convenient, easy-to-use switches/buttons/microphone/speaker/etc on a desktop panel.