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BitX40 Dial Locked

Guy WB7SZI
 

I built my BitX40 almost 4 years ago and never had problems with it. Haven’t had it on the air lately but took it out today and when I turned it on the display reads :
7,125.00 lsb TX Dial is Locked. I’m running Amunters V. 2 and never saw that message before. I did a search and found 2 messages relating to Dial Locked. One suggested depressing function button while powering on but that didn’t work. Any suggestions would be greatly appreciated. 


Regards,
Guy WB7SZI 

Allard PE1NWL
 

Hi Guy,

Your LCD display says it is in TX mode.
Is it really in transmit mode? Or is it actually in RX and is the indication on the display false?
What happens when you activate the PTT switch?
Perhaps there's something wrong with the PTT swich or related wiring?

The message "dial is locked" is normally only displayed when the tuning pot is turned while transmitting. This is to prevent frequency shifts during transmissions,

73 Allard PE1NWL

Guy WB7SZI
 

Thanks for response Allard. First, it isn’t really in transmit.  I’ll check the PTT switch and see if that’s causing problems. 

thanks-

Guy

Allard PE1NWL
 

Guy,
if it isn't really in transmit then perhaps there's something wrong with the PTTsense circuit.

see https://github.com/amunters/bitx40-raduino-v2/blob/master/PTT%20SENSE%20wiring.png

The PTTsense line is connected to pin A0 of the Arduino. Measure the voltage on A0 with a DVM.
In RX it should be LOW, it should only go HIGH  (+5V) when PTT is activated. 
If it is HIGH all the time (even when PTT is not activated), then perhaps the input pin A0 is blown.

What voltage do you have at A0 when PTT is activated (TX) and when it's NOT activated (RX)?
73 Allard PE1NWL

Guy WB7SZI
 

Thanks Allard. I’ll check those voltages on A0.
appreciate your help.

-Guy  WB7SZI 

 

Guy WB7SZI
 

Allard,
Did the voltage checks on A0. In RX and TX I’m seeing 5 volts. So I may have an issue with A0 input pin.

-Guy

Bob Lunsford
 

One comment of interest to me was that the plug in display board may have issues with it not being fully plugged in. Maybe this can be verified, also. Simple problems often expand to fill unexpected concerns.

On Tuesday, June 9, 2020, 1:33:54 PM EDT, Guy WB7SZI <sgbridge@...> wrote:


Allard,
Did the voltage checks on A0. In RX and TX I’m seeing 5 volts. So I may have an issue with A0 input pin.

-Guy

Allard PE1NWL
 

Guy,

before jumping to conclusions, let's first measure the voltage on the other side of the 10K resistor (the top of C150).
Is that also a steady +5V regardless whether PTT is activated (TX) or not (RX)?

If the voltage is always +5V also at that point then there may be a problem with the RX/TX relay (the contacts may be 'sticking').
Gently tapping the relay with the back of a screwdriver may cure the problem.

If the voltage does change when switching between TX and RX then the Arduino input may indeed be blown,
In that case you could try to use another input pin instead of A0 (need to slightly modify the code to assign another pin).

73 Allard PE1NWL

Guy WB7SZI
 

Allard,
It may take a day or two before i can get back at it. Will let you know. and again thanks for all the suggestions.
-guy WB7SZI

Guy WB7SZI
 

Bob, the display is well seated. I actually have the radio in pieces laid out on the table. I’ve hooked just the nano/display up to the computer’s usb and the message On the display says A: 7250.00 lsb. So that’s working. 

regards,
guy WB7SZI 

Bob Lunsford
 

Thanks, Guy. I am confident that the HF Sigs people are not going to let a miscalculation get the best of them. Better identification of the hardware as to where what items are used here and there is indicated. I have tool & die training in my background and grew up and was educated in Brazil so metric hardware was my first stab at hardware so I'm not too concerned about it. However, merely putting the various hardware in little plastic bags with a label that says, "For Display Mounting" would go a long way to eliminate this discussion.

Thanks again, Guy, for reinforcing my confidence in the kit-building. Pouring out the hardware with "pick and choose" approach is not for everyone. It's a quick-build kit but that does not mean some thought should not be applied.

On Tuesday, June 9, 2020, 9:25:53 PM EDT, Guy WB7SZI <sgbridge@...> wrote:


Bob, the display is well seated. I actually have the radio in pieces laid out on the table. I’ve hooked just the nano/display up to the computer’s usb and the message On the display says A: 7250.00 lsb. So that’s working. 

regards,
guy WB7SZI 

Guy WB7SZI
 

Allard,
Found problem with Dial Locked message.
it appears I had a cold solder joint between
the resistor and A0. Radio is now working normal. 
Thanks again for all you help and your many contributions to the BitX

Regards,
Guy WB7SZI 

 

Allard PE1NWL
 

Guy,
glad to hear you fixed it!
Have fun with your BitX40!

73 Allard PE!NWL