开云体育

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Jack, W8TEE

What TFT library are you guys using?

I am using a 1.8" TFT display interfaced to an AtMega644p using MightyCore.? I'm currently using UgcLib but it seems kinda slow. I can literally watch it print each character to the display.? ?The Arduino TFT Lib fails to init my display even though it is ST7735 based.? I am running on the internal 8Mhz osc and yes the CLK/8 fuse bit is NOT programmed.? I'm waiting on some 16Mhz xtals to see if that completely fixes the issue.

Watching in ernest for replies on this one.? I notice the same on my V2 - mirror signals converging and passing as I tune by.?

No. 104 - I still have functional finals though, even though I've seen the tx scale show up to 70w...? while remaining at 17-20 on the in line fwd meter.

Crocodile Hunter
Danger, Danger, Danger!? Let's go touch it!

Circuit/File Hunter
Smoke, Smoke, Smoke! Let's go take it apart!

Love it.? This is what radio is about.

- Ken

Had a little bit longer to work on my developers edition, running on its new raspberry pi four

Now powering the raspberry pi from its own 5 V wallwart source, it works fine.?

made several of the protective changes, seniors on the final gates, 5 V regulated sources interposed before the 3.3 sources, zeners on the GPIO ?pIns

happy today to find si5351 generating nice signals; set the DC bias on the comparator about equal to the fixed voltage on its other input.?

powering the 12 volts with a one amp wall wart.?

very happy to find the receiver working, with an odd twist. ?i’m embarrassed that I can’t immediately put my finger on why this is so, I’m certain there is a simple explanation ? Every signal appears TWICE in the spectrum scope, as you dial in the signals converge in the center! ? I noticed it when I put an ancient crystal calibrator and there were two signals on either side as I approached each hundred kilohertz marker ? Then I noticed I could find WWV on both sides as I tuned it in

attached is a photo of the 20 m FT8 band; ?you’ll notice there are two of them, mirror images

my brain isn’t yet comprehending what this clue is telling me. So if one of you really bright guys has already figured out exactly what is wrong, go ahead and let me know! ? Something is backwards; ?I just don’t know what, YET!! (yes, I know it was in lower side band I don’t think that is the issue the same thing happens no matter whether

in lower or upper side band)

gordon kx4z

?

Hi Daniel,

To start, I am a DE owner, not a v2 owner.

With the above understanding, my first comment is that if you did not save the files in the data folder under the sbitx folder (/home/pi/data), you have lost the calibration information, which is what is adjusted when doing calibrations.

Even with the hw_settings.ini file lost, you can copy the default_hw_setting.ini to hw_settings.ini to get started again.? All of the transmissions will be much lower than the calibrated setup.? At some point, you will need to do the calibration steps to get back the power and SWR settings.

As far as the transmission problems, all modes having the issue point to a problem with the codec output to the first mixer and onto the PA.? The output of the codec can be measured at the C91 C93 junction.? You should be able to measure an approximately 48kHz signal at that location in both Receive and Transmit modes.? I would use CW as the test mode.

If the signal is not there on transmit, check pin 2 of Q6 to see if the 2n7002 MOSFET switch may be the issue.? Verify that the gate of Q6 is at 3.3 volts.? Also, verify that the 48kHZ signal is at the source of Q6.

Use the same gate check to verify that Q5 is turning on.? I would then check Q3 to verify that it is in an active state (approximately .6 volts Base to Emitter) when transmitting.

One of the final failures on my DE took out one of the 1n4007 diodes used to switch between TX and RX.? It also took out the Q22 equivalent (Q3 on the DE TR upgrade).? The receiver was not working for that issue.

What is the current state of the receiver?? Is it working?

I would never recommend testing at 100% drive level.? It is too easy to burn out the driver or PA stages even if there is no output from the finals.

73
Evan
AC9TU

In short:
Reception is fine, HF-path and audio from the speaker are ok.
When sending, there seem to be no microphone input and no "audio mod" output to/from the audio codec.
- Which signal is displayed in the scope at the SBITX web interface? Is it the signal generated in the software? Is it the microphone input? Or is it even a demodulated "feedback" from "audio demod"?
- Which loopback device is used for the microphone and "audio mod"? I would like to test and measure this with Audacity and my scope.
- Has anyone else had this problem and solved it?

Long:
I received my SBITXv2 (complete and calibrated kit) on tuesday, serial 0270.
Since I wanted to test the device first at the dummy load this weekend, before I make operation with it, I tested only the reception the first days.
This works very well, without problems, nice interface, even on the smartphone, great work! (I really like the TRX and all its capabilities)
At some point I did an update of the debian in addition to the sbitx software, more or less out of habit. That also ran without problems.

Now I wanted to test the device yesterday for the first time on the SWR meter and a dummy load, first carefully with Drive=1..10...30...60...100.
But unfortunately? the device does not generate any transmit power. Never.
CW, SSB, FT8, TwoTone, on each band: 0 Watt output power. The current consumption increases only 2-300mA.
Since there was a test report on the device and I bought the already calibrated complete device, I assumed that I can put it into operation immediately. If you have more DIY projects on the table than free time in your calendar, you don't really want an additional tinkering object on the table. So this is now a disappointing result.

When sending with the internal and the external microphone, nothing is displayed in the NF scope, except a flat yellow line.
It seems that the microphone input is not working. But with CW there is also no transmitting power, so this is not only a problem with the audio input.


Step 1 - new image for the SD card:
Now I thought that I might have overwritten any settings or dependencies due to the debian update.
After I found a link to the SD card image, download and wrote it to the SD card (took a while), I realized that it was the old image from the SBITx-DE.
Since the download is not small, extracting and writing to the card also takes a long time, this hint in the post would have been nice...
Through another post in the SBITX group, I found the correct image for the V2, downloaded and unpacked.
The missing file extension can be solved quickly. But the image does not fit to the card that is delivered and installed by default in the SBITXv2? Going nuts... And no, buying a bigger card is of course not a real option.
With another hint in this group I found out how to shrink the image with "pishrink". That also took another long time, but I could now write the image to the card.
After 3 hours (just for the right SD-Image) the device finally booted with a new SD image.
Thanks to the community!

The V2-SD-Image is now 12GB and can be found here as 2.9 GB rar-file:
https://drive.google.com/file/d/1fzAxP5e3n19EEBIejtBU7ZmWDniRYUGA/view?usp=sharing
(Partition resizes to full card size at 1st boot)

Unfortunately, this did not solve my problem. :/


Step 2 - Measurements in the device
After I found out that "sbitx_main.pdf" didn't fit to the actual device, I came across the hint that all schematics for the SBITXv2 can be found in "sbitxv2_circuit.pdf". Here a clearer naming would be helpful, but again: Thanks to the hint in the community ;)
I bought the SBITXv2 also because all schematics are available and the board can also be easily understood and repaired by myself. I had little pain with opening the new device and however, this should not be usual for a device that is considered complete, even at this price. But ok, needs to be done...

The PA transistors were unsurprisingly (still) fine, as the unit didn't short out either.
The TX circuit around Q9, Q29 and Q28 also worked as expected.
I then tried to figure out where the RF signal was missing, tested with CW and Drive=100, in this order:
Antenna output, PA low pass input (C205/C206/C202), PA input (L80+L81, bias is also ok), driver input (C5).
No signal found.

Testing the low pass filter L16+L18+L19+L20+L21, I thought I had found the signal. At first L19 seemed to have an interruption, but as it turned out, the winding of the coil was pressed against the capacitor. A slight movement and a second later my power supply was reading 20A and the PA was toast. Going nuts again...
What I now really like about the SBITXv2 is that you can easily swap out the power amp. Unscrew the heatsink from the board, desolder, solder in, 10min work. Great! And thanks for the delivered spare FETs :)
The bias is also easy to pre-set to 2-300mA, especially since currently no RF signal goes through the PA. A little higher I turn maybe, as soon as a RF signal arrives there and I can measure that better.

Now I can't reliably measure the signal path through the mixers and the quartz filter with my scope. So I have skipped these stages.
In the path between "Audio Mod" and the first mixer there is no signal at L22 either. At "Audio-Demod" I can measure amplified noise behind Q8 (but not the sine tone when sending from CW.).
Because the audio codec sits under the Raspi I can't measure further.
Since the solder joints on the codec were not cleanly soldered, I reworked them, but without success (as expected).
What I measured was the input level from the microphone around QD1(C)/RD15, which is ok. ?
The same applies to the speaker amplifier, which is also working.
As said, the reception works fine. It seems to be a problem somewhere in the transmitting paths, probably even at the audio codec.

Now I need some help, because I just can't get any further. For this I have a few questions:

- Which signal is displayed in the scope at the SBITX web interface? Is it the signal generated in the software? Is it the microphone input? Or is it even a demodulated "feedback" from "audio demod"?

- Which loopback device is used for the microphone and "audio mod"? I would like to test and measure this with Audacity and my scope.

- Has anyone else had this problem and could solve it?

Thanks a lot for your help!
Daniel DL2AB

(Since I was perhaps somewhat drastic with my remarks:
I like the device and I really want to get it working. This is also not to be understood as a fundamental criticism of the project, although I would like to see some improvements in the documentation and on the device. I am mainly disappointed about the fact that I have now received a not quite inexpensive device without transmitting function - even if the test protocol says something different. However, as a technician, I know that this happens from time to time.
I should also add that we have already set up 12 uBitX (v5+v6) at our radio meeting and were able to solve all problems somehow. So I am confident that I will be able to use it on the bands soon, even if this now needs more work than I thought. But at this time I need some help from you :)

Aaron,

With the stock firmware, can you hold in the encoder (tuning knob) when first turning on the power and bring up the touchscreen alignment?? Does it operate correctly after the alignment?

73
Evan
AC9TU

Dave,
as far as I know, the /home/pi/sbitx/data folder contains the files that contain the setting data. The log file is also stored here.
By the way, you can easily see what the variables are by looking at the file creation date.
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Gyula HA3HZ

Joe,

you said Sbitx is at 50% of powet output to drive ext. PA getting 40W output.?

It sounds like 20W in and 40W out…?

Petr

Thank you for sharing. Useful video for Sbitx users.
It's a shame that the camera renders the close-up image out of focus, the further one is fine.
I look forward to more videos.

ps.: I assume correctly that you also used an external output stage?

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Gyula HA3HZ

hfsingals ubitx ops, qrpguys afpfsk transceiver, phaser transceiver, all do ft8 and at low power

Im usung an ubitx v6 on ft8, withabout 1/12 watts out. i turned the drive down..been running ft8 on all the bands im allowed to, and never fried an output with it.

I also own the other ones above too, and have worked massive amounts of contacts between all 3. All on Low power. Digital modes: low power.
i also run QRP SSB too when the bands are open.

ever see the waterfall when someone is operating High power on ft8 , or other modes that dont need high power? wide and all over the place.and any Dx close to the frequency they chose to splatter the band with their QRO, is lost in the QRM.

Set the WATTS to the transmit power desired.this is from the sbitx manual.

73
David
ac9xh

turn your power down when running ft8. I run about 1 1/2 watts and at most 3 watts and get very strong returns on the window. I dont own an sbitx but if you are pushing over 10watts, its way too much.Just my own opinion.Worked WAS 4 different bands,,WAC 4 different bands, and 85 countries in 4 weeks when i hit it every other day and for about 2 hours , and that was with a homebrewed vertical and with 1 1/2 watts ft8.

save the power for CW, SSB, sstv, ??? PSK31? uses i believe 80%duty cycle maybe more . its been awhile since i checked.,RTTY.
low power means cooler finals

73
David
ac9xh

Yeah but that was months ago and it was working just fine at the time.?
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'72

Dave,

the PI OS has a config file and some other folders in the OS software. might be there or in the proprietary software HFSIGNALS has created

IF you take a flash drive thats capable of accepting an SD CARD or a sd card reader, you will see the folders. I would advise you to clone the SD card first before tinkering with the original.

73
David
ac9xh

Dave,

just clone the SD CARD. or replicate it.you can transfer the info to an external usb harddrive too. lots of software out there that can do this. once cloned you can use the cloned SD CARD to make more? SD CARDS with the software. ONLY place the PI gets its info is the SD CARD. I wouldnt worry WHAT FILES, because if its sent from Ashhar, then all is mostly important on the SD CARD. Just clone it and be done with it.

73
David
ac9xh

Opened it? up? this afternoon, and the transistors that I think are the finals (two in the middle connected to the heatsink)? are toast.? I'll look around some more, but the more I read on this problem, and it seems to be common, the more I wonder if it is worth the effort to fine replacements, get the old ones out and then install new ones.? Likely, I'll find that some other things were blown as well.? Oh well -- set it aside and maybe get back to it in the fall-- make it a project!!!