Topics

Frequency and BFO alignment of uBITX v6

Ashhar Farhan
 

I have made a video that shows how BFO and Frequency calibration works. You have to do both together. Watch the video. Let me know if there are any gotachs (I got the frequency of AIR wrong)


- f

Reed N
 

Great video! Clear visuals and explanations.

One detail that probably would be good to add is about the side band inversion if the BFO is tuned "backwards".


Reed

Ashhar Farhan
 

Hmm.. I should have thought of that! 


On Wed 26 Feb, 2020, 2:31 AM Reed N, <greenkid336600+groupsio@...> wrote:
Great video! Clear visuals and explanations.

One detail that probably would be good to add is about the side band inversion if the BFO is tuned "backwards".


Reed

RussB
 

I watched the videos this morning and received my V6 this afternoon.  So, this weekend I will have a chance to do some tinkering.

I checked the website for final stage power adjustment t on the transmitter.  I didn't find anything.  Can I use the same instructions for a V5 or V4?
Thanks,

Russ  WD9DD

Richard Spohn
 

Ashhar, this video - and the BFO tool online - are really excellent.
Question: I have a v5 to build. Couldn't I use the online BFO
alignment tool with the v5 as well? There would seem to be no
essential difference between v5 and v6 as far as the audio and
alignment are concerned... thanks and 73, Rich WB2GXM

On 2/25/20, Ashhar Farhan <farhanbox@...> wrote:
I have made a video that shows how BFO and Frequency calibration works. You
have to do both together. Watch the video. Let me know if there are any
gotachs (I got the frequency of AIR wrong)

https://youtu.be/t6LGXhS4_O8

- f



Evan Hand
 

Richard,
I have used the BFO online tool (as well as a free audio spectrum analyzer program) for my v4 and v5 ubitx.  The only difference is the BFO frequency; the audio out and the width of the pass band of the filters are the same; approximately 2.5 KHz.  The v3/v4 crystals are 12 MHz, the v5/v6 are 11.059 MHz

73
Evan
AC9TU

Richard Spohn
 

Thank you Evan! Actually according to your email, the v5 and v6 have
the same crystals and frequency, so the BFO alignment should be
identical! I also have "Spectroid" as well as another audio spectrum
display app on my Android tablet, so that will prob work as well as
the online tool from HFsignals...Thanks! - Rich WB2GXM

On 2/27/20, Evan Hand <elhandjr@...> wrote:
Richard,
I have used the BFO online tool (as well as a free audio spectrum analyzer
program) for my v4 and v5 ubitx.  The only difference is the BFO frequency;
the audio out and the width of the pass band of the filters are the same;
approximately 2.5 KHz.  The v3/v4 crystals are 12 MHz, the v5/v6 are 11.059
MHz

73
Evan
AC9TU



Dave Esquer
 

Folks,
I just received my uBITX v6, great tinkerer's project.  I did your excellent alignment procedure, thank you for the clear directions.

But, after the cal, and using the reverse beacon network, 

I sent CW at 14048.9 and was heard on 14049.7
I sent CW at 14052.0 and was heard on 14052.7

At least I’m getting out and my spread is sorta consistent. I did not have RIT on, but that shouldn’t affect anything..

What the heck is going on? Any insights?

My USB AND CW lights on the screen are on, I can’t seem to just have the CW light on by itself.

CW has to have either USB or LSB on, I guess?

Lots to learn,
Dave, K6WDE

Evan Hand
 

Dave Esquer,

The stock firmware for the v6 ubitx (and all prior stock firmware) have this issue.  It is how the program was written.

There is a fix on Farharn's github as well as Reed's 
https://github.com/afarhan/ubitxv6

Reed's hex file is here
https://groups.io/g/BITX20/message/75440

It also includes the screen speedup fix that Reed developed.

I do not have a v6, so have not tried any of this. Please verify and use at your own risk.

73
Evan
AC9TU