QD Adapter - Testing the first revision PCB
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- Опубліковано 11 вер 2024
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Link to project and downloads: github.com/nic...
The first adapter boards I ordered before I redesigned the board and layout have arrived. These need to be soldered with the sockets as I didn't realise at the time I could get them populated by JLCPCB. But still able to test it out as the circuit is still the same.
Sehr stark. 👍
I ran into a buzz issue with my audio cable coming from a direct out on a mic preamplifier, to a Baofeng speaker/mic plug-in adapter. The issue was placement of the cord too close to the darn radio. DC blocking capacitors were added, and microphone removed to accommodate the audio cable from the preamp prior to utilization due to 3V bias for the microphone.
Getting the cable away solved the issue. I am sure a more robust shielding for the cheap audio cable would help as well, instead of the 'ground/shield' usually being bare stranded wire, not wrapped around the conductor.
An interesting thing that my UV-K5(8) does when on, is pulses, causing RFI when transmitting on a different HT at a very low power of 0.05W (TH-D74A in EL power mode). It would not have been noticed if the transmission was 0.5W, as I tested at that power level (L power mode) and the pulse was not audible in the SDR.
SDR was recording audio files, with speakers muted to mitigate any feedback.
Question about the adapter you are creating compared to the AIOC one:
The AIOC adapter states it only allows for digital modes, but has only been tested with aprs transmission. I am confused to say the least. The way I have been decoding with fldigi and wsjt-x is by creating a virtual audio cable and piping the SDR's output to the software, as well as a virtual com port with com0com to interface with the tuner. Can this not be done with the AIOC adapter?
It seems the one you have I can just pipe the analog audio however I chose to do so? I am guessing the "bandwidth" of the signal will be max whatever Wide FM can listen to?
Great project with the software AND firmware!!!
I have another K5(8) on the way , and it is all your fault. A fun comparison between yours and IJV's firmware should be enjoyable. I think interfacing constantly with the second radio via PC will be a nice thing for having TX capabilities.
If using the Baofeng programming cable with your software, am I correct to assume the audio will in no way be able to get transmitted to and from the PC for RX and TX capabilities? All controls of the radio would be available otherwise.
Thank you for your efforts! I will enjoy seeing how this project progresses.
Get some tin foil around that adapter of yours to see if RFI is eliminated! It works in a pinch, and does excellent if wrapped a couple times around plastic housing. Get the thick stuff, as the paper thin is less than useless for this use, speaking from experience. If you have copper tape lying around, even better.
There's a lot of RF bypassing dotted around, as well as coupling caps for the audio. It does seem to be quite RFi resistant when bare. I tested it with a rubber antenna with ferrite clamps around everything without a problem. The main issue this has (and the newer ones, the later revision to this) is that damn serial bleed-through to the audio. It's present on RX and TX. Thing is the AIOC doesn't have the issue on RX, but it does on TX, I'm guessing that's because the Mic audio is just far more sensitive and the cross-talk is happening inside the radio itself. I'm still puzzled as to how it's getting into the RX audio as I was very careful to keep all audio paths isolated on the PCB, surrounded by ground fill. Any point where Serial/Audio traces crossed on opposite sides of the board do so at right angles to minimize any coupling. Yet still there is serial artifact that's audible. There's also a weird effect it has on the battery level, I had to go into the secret menu to recalibrate the battery in order to allow TX in normal mode. Kind of odd as I don't even touch the power, it's not connected. Regarding your question, APRS can be done without any virtual audio paths with the AIOC or this Adapter, you just select the devices for audio in/out of the radio in the TNC software. Still need the com0com virtual serial port though.
Very very cool👍😎
you could try surface mount ferrites across audio out tracks and ground 470ohm@100mhz. im not a professional just like the hobby. thanks for your great work
Thank you very much for your job...
Ass: Matoz
Curious if you see an advantage of using this board over the aioc with the sound card built in?
The AIOC is still my recommended way to interface the radio. This is a passive adapter that gives line-in and line-out to the radio which can have other applications. It's also cheaper and was supposed to cut down on cross-talk which the AIOC suffers from very badly, although that didn't pan out too well on this revision. It's just another option, and having options is never a bad thing.