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SUCCESS (mostly).? Replacing the Nano and loading the correct hex file using XLoader, incidentally the same file I had tried earlier, I am now hearing signals on all bands,
Calibration is not quite on though and I'm not hearing ssb as I should. It seems as though the BFO settings using Farhan's tuning tool is not quite doing it. So I'm recalibrating, again.
But I'm 99% there and that is a cause for celebration.
Thanks for all the help. I think this is going to work out and it certainly has provided a lot of learning.
72
Grover K7TP

Here is a PDF of the Radio and Audio screens that I use for FT8 on the uBITX.? This is with the Sabrent USB audio dongle on Windows 10.? As I stated earlier, I am using isolation audio transformers to reduce interference.

73
Evan
AC9TU

Aaron,
I would suggest that you start with FT8 protocol on one of the US frequencies:

80m	?	3.573	?
40m	?	7.074	?
20m	?	14.074	?

From the picture, it looks like you are on the JT8Call frequency, which I have found to be sparsely populated.? Also, there is little activity on 20meters in the evening, most go to 80meters.? As long as you do not transmit, you should be able to receive on any antenna (I have even received signals on a dummy load).

Note: without CAT control, you will need to set the frequency manually.? It looks like you do have CAT connection per the WSJT8-X screen print, so you should be able to select the frequency through that control.

Let us know when you get the receiver working, then we can start on the transmission.?
73
Evan
AC9TU

If you unplug the USB audio dongle, do you still see the one audio device in the WSJT-X?
When I plug the dongle into my pc, if see an additional audio input device, the inbuilt audio card and the usb dongle I have just connected.

From your description, it appears that your pc might not be detecting the external usb audio device - if you plug a headset/speaker into it do you get audio out to it?

The gate does not draw any current in mosfets.

Raj

At 31/07/2020, you wrote:

Hi Aaron,

There a good amount of overlap, so you might still find the CAT section useful.

A few sanity checks:
1) if you unplug the audio cable from the radio, do you hear the signals you're hoping to receive?
2) if you unplug the audio cable from the computer adapter, does the 60Hz hum disappear from the waterfall?
3) if you increase or decrease the volume knob on the radio, do you see the amplitude of the 60Hz hum change?


Reed

Peter,
The readings for Q90 do look suspect.? I would suggest removing it as a starting point, then measure the resistors again.? Q90 has been know to fail, mostly from nearby transmitters when the uBITX is connected to an antenna.? I have not heard or read of it going out because of low or high SWR on TX.? Back to Back 1n914 or 1n4148 diodes across K1 pins 12 and 16 can protect the BE junction of Q90 when not transmitting.? The threshold voltage of the diodes is high enough that it will not affect receiver sensitivity yet still protect Q90.? Alternative is to make sure that the antenna is disconnected or grounded when using other transmitters nearby to it.

Just my thoughts,
73
Evan
AC9TU

Reed I'm still running the default sketch from HF Signals
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'72

Ok I will concentrate on receiving for now. I'm not quite ready to hack away at my audio cable yet.?
I plugged the audio cable from the pink audio input on the sound card device and the other end on the audio from the uBITX. I then opened up WSJT-X and no signals at all on the waterfall.


I then go over to the Audio section under the Settings section. For Input, I have one option only and that is "Microphone (USB Audio Device)"

On the Volume Mixer on my PC under the "Device" option I have it selected on the "Speakers" option and I have that level set at 100. Under the Applications, I have the system sounds set at 50
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'72

So I may have found the source of the issue...

Q912,Q911,Q93,Q92,Q96,Q97 all seem to be happy campers.... Emitter = 0.5V Base = 1.2V Collector =12V
... this seems to be all very uniform and on spec from what I have read.

Q90 however seems to have taken one for the team.... Collector = 12V Base = 0.34V Emitter = 0.02V... it seems poorly....

R82 = 100ohms R83 = 2.2 ohms (looks ok)

R81 = 188 ohms R80 = 25 ohms (looks dodgy especially as R81 is supposed to be 1K)

Not sure what has went on here but it looks like I need to change these resistor and Q90.

Aaron,
I have used that exact dongle to connect an HP laptop to a v4 ubitx running KD8CEC software on the uBITX.? I am not suggesting that you change out your software, as that would require a screen change, however I do believe that the audio and cat control should be the same.? Be sure to wire both the tip and ring of the mic input to the audio out of the uBITX.? That is a stereo input device and the WSJT-X software seems to average the reading of both channels together, putting a lot of noise on the unconnected input.

Others have said that they were able to wire the audio signals directly.? I could not get that to work.??I did add an EasyDigi interface for the transformer isolation.? Out of all the hardware on the EasyDigi, only the 600:600 ohm isolation transformers are being used.? It would be less expensive to just by the transformers, as the CAT interface handles the rig control.? Even with the transformers, I still needed to add ferrites to all leads to block RF from causing problems.

I do not have WSJT-X on this computer, however, the settings were pretty simple.? I used the Yeasu FT-857 for the radio, 38400 for the baud, 8 bits, 2 stop bits, and CAT for the PTT control.? I know there were some other settings that I just do not have right now, however with the test feature you should be able to try different settings on that first radio setup page to get it to work.? The input and output for the audio is of course the Sabrent dongle.? You can see what that is in the device manager of Windows.

The volume setting on the uBITX was very sensitive, I had to run it just bearly on to keep the signal bar in the green.? The output setting of the WSJT-X to the uBITX needs to be checked.? I used my power output meter to adjust the level to get about the same power reading as CW would produce on the key down.

Above are what I remember from the last time I set up the uBITX.? I have since gone to either my IC-7300 or a Hermes HL2 for any of the weak signal modes.? Just not gone back to the uBITX for digital in a while.
73
Evan
AC9TU

The sound input options for WSJT-X are under File>Settings, on the audio tab:


The radio tab has the CAT setup. See the manual linked over on this thread if you're running my software version: /g/BITX20/message/80615


Reed

Hi Scott,

There are a lot of spots you could be running into issues, but I'll try and highlight the overall approach. Let me know if there are specific parts of this that don't make sense, or need clarification.

Receiving should be pretty straight forward: connect an audio cable from the uBiTX audio output jack to your pink audio input. Once connected, you should be able to receive the audio into a program of your choosing. Just make sure you select the right audio input device!

For transmitting, the wiring is still pretty easy. Take a second stereo 3.5mm jumper cable, and disconnect the ring conductor with a little cable surgery. This disconnects the PTT on the radio side, while leaving the audio input on the tip, and ground on the sleeve. Plug this cable in between your USB green audio output and the radio's microphone/PTT input. Additionally, connect your radio to your computer with? USB, so that you can activate the TX with CAT control. You'll need to configure whatever software you're using to use CAT control for TX, and to send audio to the correct audio device.


Reed

Peter,
First off, I will assume that it was working at one time.? Since the issue started have you tried CW?? Also, I noted that you have power on 40 meters.? Is it above 7 watts?

If you truly have power on 40 meters and not on any other band then I would look at the LPF relays to verify that they are working.

Just some suggestions and questions.
73
Evan
AC9TU

Hi,

What was the current draw before re-adjustment?? That would indicate how far off the bias was (but not how balanced they were).

What is an "MJE"?

I adjusted the bias as per instructions, 470ma baselines and 670ma on key, if I roar into the mic it goes up to 710ma. They did not seem to be massively misaligned.

Hello everyone.?
I'm trying to get my uBITX V6 set up for some digital modes and I'm used to using a SignaLink but with the uBITX I'm trying to use the Sabrent USB Sound Adapter

Unfortunately, I am unable to figure out the settings for it to work. I have not been able to get it to receive or transmit. I'm not sure if it is from the software (WSJTX), the computer or the soundcard settings. Does anyone have any ideas?
'72

Hi,

Why should there be voltage across R97?? Unless the gate on the final is blown, there should be no substantial current flowing through R97.

If you didn't turn the bias voltages down to zero before powering up, you may have blown one or both of the new finals already.? The bias voltage is unique to each transistor because the gate cannot be made exactly the same on every single one.? If the bias was set higher that was needed for a transistor, very high current would be allowed from source to drain and this can cause the channel to burn out.

73,


Mark