Re: uBITx intermittent cw transmit

Howard Fidel

Take your voltmeter and monitor the voltage at the blue wire pin 2 on the Raduino. It should be ~ 0 volts when the key is pressed and +5V when not pressed. If it isn't you have a wiring issue, if it is possible Raduino issue.


On 8/17/2018 3:15 PM, Joe Milosch wrote:
I recently built my ubitx, and after assembling
it received perfectly.  I just got my HAM license,
so I decided to see how the cw key function worked.
There seems to be a problem.

I am using the stock software which came with my
July 2018 delivered ubitx.

The PTT function works perfectly, just the slightest ground
puts the ubitx into Tx voice mode.

With CW, the story is different. 
First, the instructions are pretty shoddy, and only because
I could trace the wires from pictures in some setup instructions
was I able to figure out the wiring to the various 1/8'' female 
connector sockets.

I found there was no mention of the keyer socket PIN 3 connection
to the yellow ground wire of the Arduino, and it seems that
I needed to make a wire jumper to connect the keyer socket ground
to the Arduino yellow wire at PIN 4, the Arduino ground.
I guess they assumed a metal chassis would make the connection?
I have a plastic chassis.

So OK, got that glitched fixed and I fully expected it to work.
I had 5 volts connected to the 4.7k resistor, and the blue and green
wire connections were correct.

When I tried to key, nothing happened. I thought it might be a dirty
straight key, so I tried monmentarily jumpering the blue wire to
ground. It correctly went from 5v to 0v on each contact.

Now this is the weird part. If I repeatedly touched the blue wire
to Arduino ground ( yellow wire ), the cw tx mode would suddenly
start, with TX power and proper sidetone, then suddenly stop.

There is no pattern to trigger it. If I repeatedly touched and 
shorted the blue to yellow ground, I would randomly get
a burst of dits and dahs, then it would stop. I could repeat this
over and over, but without finding a definite pattern.

I thought maybe the Arduino board had a bad solder joint,
or some other intermittent problem, but I'm also wondering
if the stock software is flawed in the cw portion, and the Arduino
is having a hard time detecting the voltage drop of the key.

Before I go any further in ripping this thing apart, I would
hope one of the ubitx experts can provide an answer to this.

Thank You,
Joe Milosch, KN4OND, Mauk, GA, USA

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