30 ‐ Connection between radio and PC
with the programming cable (TX & RX data)
- the radio tells continuously the information on the radio screen
- the radio listens continuously to instructions given from the PC
In parallel, the Microphone and Speaker are connected to the PC (as Line-In and Line-out)
The app will work with just the programming cable but you won't be able to hear the radio's audio as the programming cable cuts out the main speaker. You also won't be able to properly transmit as it cuts out the radio's microphone too. So to transmit voice you'll need an external microphone also.
In order to hear the audio you'll need to make a simple wiring harness. I made mine from 2.5mm/3.5mm stereo Y cable adapters, a 47k resistor and a 3.5mm stereo patch cable.
- Cut one of the tails of the 2.5mm adapter in half and isolate the inner conductors on both sides, there will be three, An outer shield which is ground, and two wires, one of which carries the audio and the other carries the serial TX.
- Determine which of these is the audio. It is the wire connecting to the tip (end) of the 2.5mm jack plug, you can use a multi-meter in continuity mode to do this.
- Cut back and isolate the audio wire on the tail side (non radio side) as this is not used.
- On the radio side connect a 47k resistor to the audio wire.
- Cut off one of the ends of the patch cable and isolate the inner conductors, there will be three, an outer shield for ground and two inner wires which carry the left and right audio channels.
- Connect the inner wires together and then connect this combined wire to the other side of the resistor.
- Connect both sides of the tail grounds (outer shield) back together and connect those to the patch cable's outer shield.
- Connect the tail's TX data lines back together.
You may be wondering why you can't just use an external speaker, the reason is because the audio needs to be converted to high-impedance to prevent the audio bleeding over the serial data. If you just connect a low impedance speaker (like in a speaker microphone) and the programming cable using the Y adapters, when there's any audio from the radio, the serial line gets flooded with garbage data.
As previously mentioned you can just use a programming cable alone without any audio, but if you're using the wiring harness
- plug the programming cable's 3.5mm jack into either of the 3.5mm Y cable's tails.
- The programming cable's 2.5mm jack should be plugged into the UNMODIFIED tail of the 2.5mm Y adapter.
- The microphone's 2.5mm jack should be plugged into the MODIFIED tail.
- Plug the microphone's 3.5mm jack into the remaining tail.
- Plug both Y adapter's jacks into the radio.
- Connect the 3.5mm patch lead to your PC's line input or you may use any device that can accept audio line input.
- Provides the combined function of programming cable and sound card in one
- More detail info on https://github.com/skuep/AIOC
- The soundcard can be activated and heard via Enabled Passthrough
- In this video the optimal configuration is explained
- See here aioc-works-fine-with-qs-dock
The microphone has an earplug at the bottom.
The radio audio also comes from there. You do have 2 cables to your microphone, but it is just as easy to make.
Possibly add a resistor internally and possibly also a capacitor due to DC voltage from the UVK5(8) on the audio-signal
You can also use a second 2.5 mm Y-cable/Split cable to split the audio to the PC.
- And then insert the resistor into the 2.5mm plug in the line to the PC.
- And then insert the resistor into the 2.5mm plug in the line to the PC.
The 3.5 mm hads No Gound signal. So the 3.5 mm Y-cable is RFI-sensitive to HF-interference.
.... see Issue #5
reference: Use Digirig for Computer Aided Transciever (CAT)
This nice board combines all the Y-wiring. Credits to Paul Bartlett
- Top-left (2x); 2.5 mm and 3.5 mm cables to the radio
- Top Right; audio to the PC
- Left bottum (2x); the Programming cable
- Right bottum (2x); the External Microphone
If you use QD just for scanning, you can make a very simple interface without a microphone connector. Credit to @Karol 👍
The original USB-to-radio cable is missing the audio line.
- So replace it with a 2.5 mm cable and a 3.5 mm cable to the USB-program-interface
- Internally connect the audio to an extra 3.5 mm cable to line in of your PC.
- Do not forget to add the 47 KOhm resistor (I also advise an 47uF elco in series)
If the PC has an 4 pin connector. The MICrophone can also be connected to Speaker or Line-out of your PC. Than it is (almost) an AIOC.
This cable works pretty well with js8call with voice cat control
- Cat is going via USB
- Voice via jack
It is a combination of being easily available; off-the-shelf parts that will function in exactly the same way as an AIOC, but not in such a small, elegant package. But since obtaining an AIOC seems difficult, an alternative that anyone can buy and build seems like a good compromise. A kind of GAIOA (Ghetto All In One Abomination)
This is my initial schematic for the GAIOA
And here is the mockup of the connections on the radio side jack plugs.
A mockup of the PC side jacks will be done in short order.
- See the video (press on picture below)
Ludwich66 is documenting this project on his Wiki