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uBitx V6 deaf & dumb


SM6MOJ
 

I took the outer connectors off a V6 and installed the mother board in an Inkits case that I had. The original connectors were linked to the circuit board by 3" long pieces of thin wire. The 12V connector on the board was the same as the V5, so no problems there. All was OK and I was able to configure the radio. It sounded good.

Then I pulled the screen off and installed a 2.8" Nextion and CEC software. The radio went deaf on me. I can use the morse key and hear the side tone. Full 10 W power out. But the receiver is deaf as a post. It can just hear a very strong signal. The microphone PTT works, but there is no SSB power output.

I suspected a software fault, but it did  not help to reload the software and the settings backup from the original V6 installation. have tried a different Arduino and LM386, but no change.

Are there any suggestions about what to do next?


Evan Hand
 

SM6MOJ,
I would first verify that you do get a difference in background noise between the antenna connected and not connected.  That would be a quick check on the amplifiers working.

I suspect that you do not have the correct version of the software for either the KD8CEC or stock from HFSignals.  For the KD8CEC software, you should use the v5 code.  That is set in the ubitx.h tab on line 26 here:

IF you are compiling from the source.

I would recommend that you reload the KD8CEC firmware with Xloader, selecting the correct file from the uBITXV5 folder in the zip download from here:
https://github.com/phdlee/ubitx/releases/tag/v1.20

If you go back to the stock v6 firmware be sure you have the v6 HFSignals stock firmware.:
https://github.com/afarhan/ubitxv6

Let us know what you find.
73
Evan
AC9TU


sm6moj
 

I did upload UBITXV5_CEC_V1.200_NX.hex
There is no noticeable change in sound when I connect an antenna.
Have tried several different microphones, with the same result.


Evan Hand
 

SM6MOJ,
Since you have the correct hex file loaded, and connecting an antenna does not increase the background noise, then you have one of the receiver's stages not functioning properly.  This points to a hardware issue, not a software or calibration issue at this time.

How to go about isolating the problem stages will depend on the test equipment that you have.  Assuming that you have at least a DMM, you can start with some static voltage checks on the main transistors.  Focus on getting the receiver to work first.  There is a file in the files section provided by Vu2ZAP.  Do a search on his call sign and you should find a couple of spreadsheets for a v4 µBITX.  These will be close to the same values for the v6.  The main thing that you are looking for is that the transistor is in its active region:  The base being 0.6 to 0.7 volts above the emitter.
https://groups.io/g/BITX20/files/VU2ZAP

The other method that works with minimal equipment is to take a piece of wire or metal tweezers and touch the end of the wire to the test points starting with TP20, working backwards through the receiving sections of the rig.  TP20 should introduce an AC hum in the audio section, if not then the audio section is not working.  The other TPs in the receiving stream will show up as a hiss.  The TP where the hiss no longer increases is the stage that has the issue.

I would suspect that you have an audio wiring issue, as you did say that the problem occurred when you removed the controls from the mainboard.
73
Evan
AC9TU