I have a lovely Wouxun KG-UV950PL 6/4/2/70 mobile radio, but a hands free kit doesn’t seem to be available. So I set about working out the connections required to build one. Here they are:
Using a standard RJ45 Ethernet cable:
- Orange+white / pin 1: RX audio – NC for this application
- Orange / pin 2: +5V on receive (unverified) – NC for this application
- Green+white / pin 3: PTT – wire to one side of switch
- Blue / pin 4: unknown, probably buttons – NC for this application
- Blue+white / pin 5: unknown, probably buttons – NC for this application
- Green / pin 6: +8V constant – wire to 2.2k resistor, then to positive side of mic
- Brown+white / pin 7: ground – wire to ground side of mic and to other side of PTT switch
- Brown / pin 8: – TX audio – wire to negative side of 100μF capacitor, then positive side of the cap to positive side of mic
Looking forward to building a version for the car and seeing how it is for road noise etc.
According to this, increase resistor size to increase mic output level (sounds counter-intuitive, but hey).
Update: that 2.2k resistor should be a 47k. That seems to produce clean audio and keeps the current through the mic element down. I’ve ordered a MAX9812 module to see whether a pre-amp brings the punchiness of the audio up a bit, since it’s a bit quiet as-is.
Hi Tom I was also playing around with my Wouxun KG-UV950P it has some modulation issues, the modulation can drop off and after switching the unit on and off modulation will come back, So I played around with your circuit to hookup an electret and also injecting a signal from a generator to see when this problems occurs, turns out there is an audio limiter IC D2761 on the front panel PCB I have been looking into that bit of the circuit, cleaned the tracks around pin 4, these are very high impedance, seems to hold up for now. I tested for more than 20min straight modulation.
Pins 5 and 4 on the microphone RJ45 connector got me intrigued so I had a look at the signals. What I found was varying DC voltages depending on which button was pushed.
So normally voltage on pin 4 and 5 sit at 5.14 V between pin 7 common
pressing :
Main 4.220 V pin 5 | 4 0.966 V pin 4
Menu 0.992 V pin5 | 5 1.770 V pin 4
Up Arrow 1.600 V pin 5 | 6 2.360 V pin 4
Down Arrow 2.190 V pin 5 | 7 4.120 V pin 4
Exit 2.590 V pin 5 | 8 3.920 V pin 4
1 4.010 V pin 5 | 9 3.630 V pin 4
2 3.770 V pin 5 | # 3.160 V pin 4
3 3.450 V pin 5 | Squelch 4.28 V pin 4
* 2.950 V pin 5 |
73 Mark PE0XJ
Hi This will be a good start have boom mike set up in car for yaesu and worked with TYT 4 BAND no mods. good reports.
Only had radio a few days finding my way arround it looks fantastic value.
Cant work out how to put a freq into memories. Going to try with computer all new to me at 71 years. G0ENN SOUTHEND ON SEA ESSEX.
Also run 7300 into 5 element crossed Yagi. bernie@oldradios.co.uk