Having seen Farhan's great news that the uBitx is finally here and available for order I am now eagerly awaiting mine to make its way from India. I am hoping that it will be here before the end of the festive season and that I might have the chance to get mine on air before returning to work.

My mind is already running wild with ideas for modifications and hacks (after much fun experimenting with the Bitx40), but I guess I should get the vanilla version working first before I make too many changes.

I am going to document everything on this blog and also add some of the useful ideas I pick up from elsewhere.

Some initial mods posted by Arv K7HKL:

Adding a rear panel switch to change the RF PA voltage from 12 volts to a higher 
voltage.  The power connector has 3 leads (Ground, Radio, and PA) to facilitate 
this mod.  What it does require is a 3-conductor rear panel power connector, or 
maybe two power connectors with one being 12V and the other being higher 
voltage for the PA section.  Both these power inputs should probably be fused 
at 2 amperes.  A 1A diode is provided in the kit for reverse power protection.  
Since I have fused the power input at 2A I changed this to a 3A diode at both 
power inputs.

At the antenna connector on the rear panel I will be adding a 'current transformer' 
arrangement for monitoring antenna current.  This initially will drive a Red LED 
on the front panel.  I'm hoping that some future software version will include an 
ANTENNA CURRENT indication via a spare ADC input.  Alternatively this 
could be an SWR bridge built into the rear panel with Arduino measurement 
and display capability.

There seems to be a small possibility that the LCD display backlight area can 
short to the USB connector shell on the Arduino NANO.  For this reason I 
have added a small section of electrical tape over the connector shell.  This 
short can happen if you press the LCD back during or after mounting in the 

chassis.In order to facilitate computer interface to the uBITX I made wire additions
at the MIC jack, the SPEAKER jack, and added a lead from the hot side of 
the volume control potentiometer.  The MIC jack is a switching type so it is 
easy to add a lead to pin-5 for bringing out PTT to the rear panel computer 
connector.  Pin-4 of the MIC jack is microphone audio input so this lead is 
also brought out to the rear panel computer connector.  Unplugging the mic 
now connects the microphone audio and PTT to the rear mounted computer 
connector.

The SPEAKER jack is also a switching jack so I added a lead from pin-4 
to a 2-conductor switching jack on the rear panel.  This let me relabel the 
SPEAKER jack to EARPHONES and install it on the front panel.  The added 
jack is labeled EXT SPKR and is installed on the rear panel.  This lets me 
insert an earphone plug into the front mounted jack to silence both internal 
and external speakers.  Inserting a plug into the rear mounted EXT SPKR 
jack silences the internal speaker that I installed inside the uBITX chassis.

The chassis rear panel is perforated with several 0.25 inch holes close to 
the RF PA heat sinks with a 2 inch square fan mounted outside the chassis
to extract heat from the RF PA MOSFETs.  At present the fan just turns on 
with the main power switch, but maybe eventually it might be speed controlled 
by temperature sampling via ADC and control via an Arduino PWM output.
My build includes a 1.75 inch diameter aluminium knob for frequency control.  This 
seems to eliminate the look and feel that the frequency adjust is small and insubstantial. 
I lathe turned this knob and applied knurling around the outer circumference.  The 
volume knob is the same design but smaller at 3/4 inch diameter.

My build is not yet powered.  I anticipate that will happen within the next 2 days.  
This promises to be a lot of fun.  We owe Farhan a big thanks for this Christmas 
present.  

Arv  K7HKL