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uBitx on JS8Call / FT8

Gordon Gibby
 

Homebrew sound-card isolator  matched to my uBitx today -- ran into unexpected problem:   begin transmission and instead of a solid TX, the push-to-talk chattered in and out of TX / RX / TX / RX about 5 times/second incessantly    


Sound card isolation system is a double transformer, gain pot, vox-type circuit with reed-relay output (https://qsl.net/nf4rc/2019/SmallBoxSoundCardInterfaceManual2.2.pdf and Gerbers are on github) -- so quite puzzled why this happening when never happens with ICOMS..... and the SIGNALINK worked perfectly!


After multiple false theories I finally recognized that the PTT line goes DIRECTLY into a Nano.   Adding a bypass capacitor or two from PTT line to ground (all I had on hand were .047's would have preferred .01) -- and problem solved!!!!   Completely new discovery for me with this design.


The uBitx requires WAY more audio than I'm used to with mic input of ICOmS --had to change the fixed resistor in the audio attenuator to allow 10dB higher signal.    Then it could be adjusted with the gain potentiometer.    


After all THAT, I got it up on JS8 and immediately got 2 answers to my HB signal both giving me reasonable SNR's, and their signals were fine also.    Wandered down to FT8 land....wall to wall signals.   I'll fiddle more with that another day.    


Great rig.   Has taught me a TON -- thanks to you folks!


Gordon KX4Z


Gerbers for the sound isolator:  https://www.qsl.net/nf4rc/Tech/Plated_Through.zip

Doug W
 

I look forward to digging into your manual and circuit.  I've been using an easy digi board.  If you use KD8CEC's firmware the µBITX can be CAT controlled as a FT-817 skipping the need for the PTT with the JT modes.
--
www.bitxmap.com

Gordon Gibby
 

​​Yes -- i've done the FT-817 bit for frequency control but always just did the signalink-type PTT.   I have not yet done any of the KD8CEC firmware.    


the easy digi should work FINE -- but it lacks the volume controls and I prefer a relay to the transistor for PTT.   My preferences, maybe not yours.   I bought one early on, but didn't think it would serve the needs of our group as well.   


PUT A CAPACIToR BETWEEN THE UBITX PTT LINE AND GrOuND -- like 0.01 uf.  


There are LOTS of ways to do digital, nothing says that my way is any better than others -- it is just what we've done for a few dozen systems locally.    


I havve been using the $4.75 Adafruit 1475 --- but there are probably much better choices out there for sound card...I just haven't studied it.    For the raspberry pi's that we have used these on, they need a "classless" sound dongle.


More power to you!

Gordon



From: BITX20@groups.io <BITX20@groups.io> on behalf of Doug W <dougwilner@...>
Sent: Wednesday, June 19, 2019 11:52 PM
To: BITX20@groups.io
Subject: Re: [BITX20] uBitx on JS8Call / FT8
 
I look forward to digging into your manual and circuit.  I've been using an easy digi board.  If you use KD8CEC's firmware the µBITX can be CAT controlled as a FT-817 skipping the need for the PTT with the JT modes.

Ryan Flowers
 

JS8Call has a new feature that is great for BITX owners: In the configuration, you can have it persist the PTT between 15 second frames. It'll save a lot of wear on your relays. It's not on by default, so you do have to configure it. It's under Rig > PTT. 

http://js8call.com/2019/06/18/js8call-v1-1-0-released-today/

--
Ryan Flowers - W7RLF
MiscDotGeek.com
Multi Band BITX40
The BITX40 FAQ

Gordon Gibby
 

Thanks!


On Jun 20, 2019, at 12:28, Ryan Flowers <geocrasher@...> wrote:

JS8Call has a new feature that is great for BITX owners: In the configuration, you can have it persist the PTT between 15 second frames. It'll save a lot of wear on your relays. It's not on by default, so you do have to configure it. It's under Rig > PTT. 

http://js8call.com/2019/06/18/js8call-v1-1-0-released-today/

--
Ryan Flowers - W7RLF
MiscDotGeek.com
Multi Band BITX40
The BITX40 FAQ