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Thanks David

Part of the mistery solved...

If you remove R253, you can still hear CW side tone on speaker, because Arduino is using PWM pin for generating audio.
That pin behaves like an antenna, and signal from that pin enters receiver and comes to audio amplifier.

Regarding bumping sound... that sound is heard when CW key is pressed, and released (again, TX is OFF).
Tracing the problem, I found that when you cut the connection between CLK#0 pin from Raduino and main board, that sound doesn't exist any more (while pressing CW key).
Disconnecting the other two CLK signals (CLK#1 and CLK#2) doesn't make any difference.

What is so special about CLK#0 that makes bumping sound to appear?

73
Marko YU2MP

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I just ordered a couple of these from Adafruit.




Dave - AI6K

Does anyone have a link to a 10K pot I can use for volume control for the uBitx that has power switch. Oddly the one that came with the kit went bad on me. It just freaks out when I touch it and can go from just producing full volume to nothing at all or it just works.

Joe

I've got to think about that... I want the person in phone mode to hear my cw. If they're in USB, don't I have to transmit CW-reverse to get into their passband? Ed - aa2mz

Thanks, that was it... I think I'd changed its default in the defines but without changing the software version number, the eeprom didn't get updated.

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I have two v4 boards that are completely deaf. Haven't spent the time yet to do any tracing.

Like you, I've put this on hold indefinitely.


Dave - AI6K

Original thread was "RX Trouble". ? Sort of a rant here...

I am not superstitious but beginning to believe my uBITX (both factory & CEC firmware) is cursed. Have had issues since first power-up, but now I think the problems are fatal.? Have a lot of time & money in it (Axicom relays, trouble shooting, etc.) but think I might call it quits.? Never had problems with my scratch built rigs.? Had a problem with my K2 build, but fixed that when I discovered a copper whisker (under the coating, I took optical micrographs !) shorting a pair of runs on the control board.
However, the uBITX has been a relative nightmare.

Original issues, to name a few:
Not on frequency, low audio, poor RF sensitivity, pinched audio response (narrow - filter issue?),? very narrow tuning for understandable audio, etc.

I fixed the too low for headphones audio with an off board amplifier.? But, the distortion was even worse from the speaker. I found a power/signal driven oscillation in the external amp and fixed that.? Afterward, the volume was OK and the distortion was somewhat lower - but still not great audio.? The other problems remained.

Observation:
There was (I think, maybe) something oscillating on the board. There was a low level (~700) Hz tone on the audio coming from the board.? Found that with a 'scope, but did not find the source. Also, the 12 MHz crystal filter was rather microphonic - With no received signals lightly tapping crystals produced audio output. Normal?? Not normal?

The TX power was inconsistent with measurements by others.? Got 10 +- watts out on higher bands, dropping a bit as frequency increased.? But, for 40M and below, the power dropped to about 1.5 watts while the supply current was much higher (almost by 1 amp). ? Frustrated with the RX problems, decided to look at the TX power issue using 'scope on TPs in the TX amp stages.
-- The following is when the patient died. No brain activity ;) --
CW keyed the TX for testing but I didn't get far before the fatal problem occurred. After a few short dummy load TX sessions, it stopped keying.?? Immediately noticed a display issue.? The top row was all solid fill characters, nothing on the bottom row. Clocks 0, 1, 2 not there.? The 7805 on the Radiuno is supplying 5 v.? This is a bit subjective, but is does not seem to get quite as hot as initially? -? likely not supplying as much current as before?.
Hoping the cause was somehow corrupt firmware, tried reloading. Xloader appeared to connect and tried to upload, but never left the "uploading" mode - Failed to reload firmware.? The display stayed the same - solid top row, empty bottom row.
Tried uBITX Manager to read.? It appeared to connect, but when "Read from uBITX" was attempted, returned this:? "[8:30 PM] Error Receive Length = 0/1027".
OTOH,? uBITX Manager did report success when told to upload the .btx backup file I created earlier (Load from File).? BUT - it again failed the "Read from uBITX" command.? Display never changed.? I get the impression the Arduino died...

Ready to take it outside and shoot it? ;) , but probably will put this project away for now.? A big question is, if a version 5 is released to fix some of the original issues like spur/harmonic levels, do I try again ????????

Better luck to everyone else!
73,? Woody?? KZ4AK

?I ordered far too many of the 1K/3W resistors for this project.? I've enough of the passive components plus D1(BAV21) for four additional builds.? ?I've made up four kits consisting of 20 1K/3W, 1 56k, 2 1k (don't have 2k in my box)? resistors, D1 and C1 (50V--ok for QRP, but if you want the 150W version you should replace with a 250-500V as specified).? Drop me a private email if interested.?
John
WI6P

Moving the BFO to the other side of the 12mhz crystal filter can make a difference,
as the skirts of the filter are shaped differently.
Also, moving the VFO to the high side (on the Bitx40) or clk1 to the high side (on the uBitx)
can have considerable impact on the birdies that the receiver sees.

Dangerous to make any blanket statements here as to what works best.
The uBitx is quite different from the Bitx40.
The various firmware releases can do different things.
What is best can also depend on what characteristics you are looking for.

Jerry, KE7ER

Ty,

make sure semiQSK is ON in the SETTINGS menu.
If the radio is in LSB mode, it will switch to CW automatically as soon as you push the CW key.
(if it's in USB it will switch to CWU).
Press PTT to go back to LSB (or USB).

However when semiQSK is OFF, you need to select CWL (or CWU) manually and press PTT manually for transmitting CW.

73 Allard PE1NWL

Am 30.10.2018 um 06:43 schrieb Raj vu2zap:

Set the BFO to 11.9965 and see if that works.

Thanks Raj !

Had again to correct the calibration which was exactly 1 kHz off. After playing a while with Sunils calibration method I got it calibrated on 10,000.000 and then played with the BFO. Tested all BFO values from 11.995.0 to 11.996.5
The best result I got at 11,995.3 with -28 dB sideband rejection both on USB, LSB, full carrier rejection and nearly equal and good sound qualitiy on USB and LSB. The bandwidth was about 3 kHz.

73 Matthias, DD7NT

Hi Dave,

Obviously unattended operation is allowed where you live and are licensed. Some of that is allowed where I live too but the problem you have outlined is the main reason I don't do unattended operation. The remote controlled power switch that Kevin suggests looks like a good solution but you will still have to know when it needs to be used.

Good luck with it.

73,

Bill KU8H

--
bark less - wag more

Hi Timothy

http://www.hfsignals.com/index.php/2017/11/23/bitx40-circuit-description/ - C103 , 3 pads between xtal and T4 on the PCB for the trimmer.

If those boards were an early batch (or you have modified) the diodes (2 with balance pot?) could well be mismatched. Replacing both should bring balance within the pot's ability, particularly if you measure them with an ohmmeter / DMM. Later versions had the ready-matched pair-in-one-package.
I've a dim recollection of BFO and VFO drive levels for the Bitx40 being discussed - they're adjustable in Raduino software for the uBitx and seem to make a difference.

You might find fragments of the diagram with specific modifications, but that one above is the 'master'.

Past messages in the Group give the info, as detailed on hfsignals site 'help'. Farhan has contributed here, researching his input would give the info 'from the horse's mouth' (as it were). development is ongoing in the Group, mainly for the uBitx but bits are applicable. Above all, READ. It's all in English (as here too), so our Spanish friends may encounter difficulties there - but if successful I'd encourage a translated site (a lot of other 'Latino' Hams would appreciate it!).

From hfsinals website:
If you need information specific to your shipping, billing and other commercial matters, you can drop us a mail to hfsignals’ inbox at gmail. The mailbox is in the name of hfsignals followed by the regular gmail.com.
I feel sure an email there would gain Farhjan's attention, particularly being related to a group purchase. The boards as supplied will have a hand-written number on them; quoting those numbers will identify the batch and indicate appropriate steps - with luck replacements with latest versions, though stock may be low, the uBitx being the major production now. Who knows? I know Farhan and the whole crew are very helpful.
73 de ZL2DEX