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

U2 is putting out 5v though on TX.

Thinking about that but surely I should see something on the meter without doing that ?

Doesn't appear to be voltage across R97 which has me worried.

They seem to be, they have the dimples at the top corners.

开云体育

Did you retune the biases?
https://www.hfsignals.com/index.php/ubitx-tuneup/


Reed

... so my fun continues!

Running some tests with antenna tuning on the MJE I seem to have blown the finals or I thought I had, no watts on any band except 40m into a dummy load. Replaced the finals with two RD16's as I had wanted to do this anyway. Now testing not getting any output on any band. Note v6 has a second set of holes for the reversed pins.

Checked have 12v on final legs, on TX one gets 3.8v across the legs and the other about 4.2v across the legs.

Confirmed D8 gets 12v on TX on 28MHz and the others D11,D12,D13 all show zero volts which is expected.

Checked drivers and all show circa 0.65V and pre-drivers show 12v.

Reception is working fine but definitely not getting any output, any thoughts on what else I should be checking ?

Thanks!

开云体育

I would be interested in the value you saved when you finished the second BFO tuning step.? It might be an indication of any issues that may be in the other parts of the radio.

Note: In the stock software, you need to write calibrations and tuning values down as every time you go to tune or calibrate it starts from the same default value.? Reed N's software does not have this issue, as well as correcting what many see as the correct CW operation where the frequency displayed is the actual frequency transmitted.? In the Stock software, the CW signal is offset by the sidetone value.

73
Evan
AC9TU

Owen,
I would perform the BFO tuning step (the last one) in Ashhar Farhan's video on BFO tuning.? That is assuming that the CW frequency is correct.? If the frequency is off, then do all 3 steps.


For a v6 the BFO should be somewhere close to 11.056000 MHz (11.059 MHz crystals - 3,000 Hz highest audio frequency expected).? Most will be lower than that for the best audio and carrier suppression.

Note: The first BFO tuning step is to put the response at the lower edge of the audio passband to allow for the best zero beat response to the AM signal.? After the Frequency is set, the BFO then needs to be tuned for the best audio response and carrier suppression.?

73
Evan
AC9TU