After doing a system update with the newest sbitx app and copying the Hardware_settings.ini and web/ *.mc files over, what is in the sbitx.db and why is that saved. Thanks Barry K3BO

I have been fighting bad band noise on all of my sBitx's from the DE to my V2 and V3, finally decided and set out to find another solution. I researched the most quite Buck converter that the RC and Drone users are using and they mostly agree that this is the best one, https://www.amazon.com/dp/B07P663XJV?ref=ppx_yo2ov_dt_b_product_details&th=1 I tried it in my V3 and found it works great with no rf noise that I can see anywhere and the general noise floor is much lower than before and the best part, it runs cool to the touch after 5 hours. I'm now going to install one in my DE now. YMMV. Joel N6ALT

Thank you guys, a brief update, and I'll summarize later into one message. But for now based on new suggestions: Probing, flexing the board, touching diodes, other components, BNC connector, etc., all nothing. Tapping everything, everything seems solid. And I used it this morning to check into the NTN on CW and SSB. So it's working fine in that regard. Good RX TX, no issues with coax, antenna, etc. Only weak audio output. It is off frequency, NTN is on 7.284.00 My display is on 7.282.50. Have not aligned the BFO yet as was suggested. Will get to that. I'm using headphones and Vol is wide open. I do hear a LOUD crackle from time to time like the audio is trying to come back. Touching points listening for hum... TP1 - nothing TP2 - nothing TP3 - can't find yet TP20 - nice loud hum TP21 - very weak hum Gate of Q74 - nothing Pin 2 P2 - nothing Pin 3 of U1 - loud hum, higher pitch than base of Q70 Base of Q70 - loud hum, tone is different than Pin 3 U1 Still have not found D3 or D4. Board is out of its case on my bench. WOW! Just blasted me out of my chair for a second or two, then audio died again. Hear crackles from time to time, something intermittent, it's trying to come back. And is there a CW sidetone adjustment on the board? On CW, about blows my ears off. Audio is sure working in that regard. 73, Richard AG5M On Sunday, November 24, 2024 at 12:57:12 AM PST, tomekdm sp7etd via groups.io <tomekdm@...> wrote: Ok. I missed some previous messages. Is it not continued, same topic? Anyway, Do You have the same level of noise/hum while touching core of antenna connector and pin2 of P2 (or, TP1, TP2)? Is Your antenna and cable confirmed with other transceiver? Regards Tomasz

Today I tried to adjust the BFO setting per Farshan's video and his website - https://itshamradio.com/bfo-tuning-aid-ubitx. I had no luck at all. Perhaps because I don't have enough audio, or perhaps the original owner of this radio got it so far off I don't know where I am. I do know he tried to set the BFO and never could, or so he told me. Sadly he is now SK so I can't ask him. Right now when I go to align the BFO, I see on my screen 11.053.0. Assuming, if I am right, given the rather tight tolerances of components these days, every unit like this was probably set at the factory at some number +/-, but reasonably close. So, if you would be so kind as to check your BFO setting number, what number do you have? I would assume they should all be reasonably close +/-. Perhaps I should start there. I'm guessing this thing is way way off from the original owner trying to align it. I don't seem to be able to move the audio in the Tuning Aid screen either way. With the holidays coming I might have to put this on the back burner for awhile, which is OK. Ham radio is an enjoyable hobby, not a living. Thank you all, have a great Thanksgiving. 73 Richard AG5M

I’ve boxed up my Specan into a chassis and carefully shielded the LPF, BPF, Crystal filters, Log Amp Detector as well as the Arduino on a copper ground plane in a steel metal chassis. I am getting a -65 dBm noise floor, whereas I seem to recall getting -88 dBm when it was all spread out on a plywood breadboard, (albeit with a copper ground plane also). I see here you had a -92 dBm noise floor. Any guidance? When I de-power the 2nd Oscillator, the noise floor drops down appropriately. I have checked all the decoupling capacitors and added a filter onto incoming +12 VDc.

Tried again this morning, this time on the correct TP, TP21. I have 53.6K on RX, 2.1 ohm on TX. So according to what you (Evan) said, that's right. Everything is right so far, but I have weak audio. Time to get out the O-Scope? I do not have a schematic, does anyone have one? I used it this morning to check into the Noon-Time-Net with CW so other than weak audio it appears to be working FB. BTW, is there a setting to reduce the sidetone level? It's really loud! I'm surprised that other than through this Forum, HFsignals provides no support. Makes me a little hesitant to purchase a radio from them. Given this experience. 73, Richard AG5M On Friday, November 22, 2024 at 02:55:55 PM PST, Richard AG5M via groups.io <ag5m@...> wrote: Taking another run at this, I confirm I have Zero volts RX at the gate of Q74, if the gate pin is the one closest to D14. And I have 5 volts when in TX mode. Given this information and what's noted below, dos this tell anyone anything? Why I have virtually no audio? 73, Richard AG5M On Thursday, November 21, 2024 at 11:03:28 AM PST, Richard AG5M via groups.io <ag5m@...> wrote: Evan and others who may be following. The TP1 and TP2 I mentioned below was a typo, they were TP20 and TP21. I did the same this morning. With volume control fully clockwise. Nice loud hum at Pin 3. Considerably lower hum at TP21, and almost no hum at TP21. Turning the volume control made difference. This morning I checked the resistance measurements you mentioned at TP20. With radio on it measured 70 ohms RX, 2.36K TX. From what you mentioned then I guess Q74 is faulty? I did not make voltage measurement yet. Where exactly is Q74? I don't see it. 73, Richard AG5M On Tuesday, November 19, 2024 at 05:09:11 PM PST, Evan Hand via groups.io <elhandjr@...> wrote: On Tue, Nov 19, 2024, at 01:10 PM, Richard AG5M wrote: Was that TP1 and TP2, or TP21 and TP20? All are on the board. TP1 tests the antenna input, TP20 tests the audio after the demodulator, and TP21 is the input to the audio amp with muting. With the volume control fully clockwise, the AC hum should be the same when touching pin 3 of the LM386 as TP21. If not, then there may be an issue with the volume control. Try turning it back and forth to see if there is a broken connection. Another test is to verify that the mute MOSFET (Q74) is switching correctly. Measure the gate voltage of Q74. It should be zero when receiving and 5 volts when transmitting. Also, you can measure the resistance from TP20 to ground with the radio on. It should be higher than 5kOhms while receiving and less than 200 Ohms when transmitting. If not, then Q74 may be bad. Another problem I have seen with low signal strength is related to the Raduino board. The Si5351 chip failed to lock at the right frequency, which would appear as a jittery signal on any of the three clocks to the mixers and demodulator. In particular, the BFO seems to drop in and out of sync. This could be the case for any of the three clock signals. To test the Raduino, I removed it from the radio, powered it from a USB connection to my PC, and measured the outputs on the mainboard connection. 73 Evan AC9TU

Taking another run at this, I confirm I have Zero volts RX at the gate of Q74, if the gate pin is the one closest to D14. And I have 5 volts when in TX mode. Given this information and what's noted below, dos this tell anyone anything? Why I have virtually no audio? 73, Richard AG5M On Thursday, November 21, 2024 at 11:03:28 AM PST, Richard AG5M via groups.io <ag5m@...> wrote: Evan and others who may be following. The TP1 and TP2 I mentioned below was a typo, they were TP20 and TP21. I did the same this morning. With volume control fully clockwise. Nice loud hum at Pin 3. Considerably lower hum at TP21, and almost no hum at TP21. Turning the volume control made difference. This morning I checked the resistance measurements you mentioned at TP20. With radio on it measured 70 ohms RX, 2.36K TX. From what you mentioned then I guess Q74 is faulty? I did not make voltage measurement yet. Where exactly is Q74? I don't see it. 73, Richard AG5M On Tuesday, November 19, 2024 at 05:09:11 PM PST, Evan Hand via groups.io <elhandjr@...> wrote: On Tue, Nov 19, 2024, at 01:10 PM, Richard AG5M wrote: Was that TP1 and TP2, or TP21 and TP20? All are on the board. TP1 tests the antenna input, TP20 tests the audio after the demodulator, and TP21 is the input to the audio amp with muting. With the volume control fully clockwise, the AC hum should be the same when touching pin 3 of the LM386 as TP21. If not, then there may be an issue with the volume control. Try turning it back and forth to see if there is a broken connection. Another test is to verify that the mute MOSFET (Q74) is switching correctly. Measure the gate voltage of Q74. It should be zero when receiving and 5 volts when transmitting. Also, you can measure the resistance from TP20 to ground with the radio on. It should be higher than 5kOhms while receiving and less than 200 Ohms when transmitting. If not, then Q74 may be bad. Another problem I have seen with low signal strength is related to the Raduino board. The Si5351 chip failed to lock at the right frequency, which would appear as a jittery signal on any of the three clocks to the mixers and demodulator. In particular, the BFO seems to drop in and out of sync. This could be the case for any of the three clock signals. To test the Raduino, I removed it from the radio, powered it from a USB connection to my PC, and measured the outputs on the mainboard connection. 73 Evan AC9TU

Will the new Raspberry Pi Display 2 (1280 x 720) give the resolution we need to run WSJT and others on the built in screen? Garrett N7QWT

Hi Farhan; Looks like you are tweaking on the swr_bridge.ino program that lives in the attiny85. It looks like there could be a possibility that the message[] variable assignments, which occur in a fast loop, could get interrupted mid-stream by an i2c request from the pi, which would corrupt the forward and reverse power readings that are sent back to the pi. You may want to set a flag in the requestEvent() function, which is then used in the main loop to get an update from the ADC channels, make the message[] variable assignments, then clear that flag and just wait for the next i2c read request to come in. An alternative would be to block interrupts while making the message[] variable assignments, but this could impact the i2c code. Note: I haven't built the Power/SWR sensor circuit for my DE, but I am collecting the parts. 73; Steve, N3SB

Thank you for letting me join the group. I just became the proud owner of a uBITX v6 assembled by another Ham who sadly went SK. When I turned it on I had plenty of audio. And I already knew it needed alignment. But otherwise it was working as expected. I used it to check into the Noon-time-Net, no problem. I can get to alignment later. Then suddenly, the audio dropped to such a low level I could barely hear the station with volume control wide open. Same for speaker and headphones. After some time passed, perhaps 15 minutes or so, the volume popped back to normal. About blew me out of my chair. However, the next time time I turned it on, VERY low volume again. And it has stayed that way since. Barely audible. Not being familiar with this radio, can someone give me some ideas how to trouble shoot the missing volume? Where to look. I do have the schematic. Will be much appreciated. 73 Richard AG5M