So it sounds like there is something amiss with Q23 Q24 and/or the relay. You can ground the Q24 side of the relay and see if that operates it OK. this is not a problem with your digital board but the discrete components that switch the relay.
You need to triple check the circuit round these two components. Somehow they are pulling the line low (ish). Farhan is suggesting changing your 10K pull up to be 2K2 but I don't think that's your problem (it is a good idea generally though).
When you apply 5V to the base of Q23 via 4K7 that should cause the transistor to conduct and ground the base of Q24 which in turn removes the 5V from the base and hence opens the relay. With the PTT operated the base of Q23 is pulled to ground and the base of Q24 is then held high by the 2K2 resistor and hence the relay is connected to ground as the transistor Q24 is conducting.
Please check carefully and report back. M On 28/02/2014 08:57, jerry@xxxxxxxxxxxxxxxx wrote:
Yes, the PTT toggles it between RX and TX. When I disconnect the R/T line from the digital board it changes the display to RX. When I connect it to the mainboard it goes to TX. The relay stays in TX no matter what is connected. Jerry K5LRU Harwood, Texas-------- Original Message -------- Subject: [minima] Re: Stuck in Transmit From: Thomas Sarlandie <thomas@xxxxxxxxxxxxx> Date: Fri, February 28, 2014 2:49 am To: "minima@xxxxxxxxxxxxx" <minima@xxxxxxxxxxxxx> Jerry, If you keep just the PTT switch connected to pin 5, do you see the minima going from RX (default) to TX (when you press the button)? How is the relay when Q23 4.7k resistor is unplugged? It should be in RX. You say nothing happens when you connect it to +5V. Then the relay is always in RX and never goes to TX? I am confused because before you said that you were stuck in transmit. 73, thomas On Fri, Feb 28, 2014 at 12:42 AM, <jerry@xxxxxxxxxxxxxxxx> wrote:With everything disconnected except the pullup the voltage on pin 5 is 4.94v. With the pullup removed it's 4.82v. Connecting 5v to the r/t pin does not activate the relay. Connecting 5v to a 4.7k and touching the base of Q23 doesn't operate the relay either. Maybe a bad relay? Jerry K5LRU Harwood, Texas-------- Original Message -------- Subject: [minima] Re: Stuck in Transmit From: Mark G0MGX <mark.g0mgx@xxxxxxxxx> Date: Fri, February 28, 2014 2:31 am To: minima@xxxxxxxxxxxxx "The voltage on pin 5 is 2.24" - that's the problem. We need tounderstand why. The Arduio will see that as a LOW (because its less than 2.5) and hence you are in TX.If you disconnect everything from pin 5 except your 10K pull up to +5Vwhat happens then? What is the voltage on pin 5? When you remove the pull up resistor whats the voltage then on pin 5?With the line to pin 5 disconnected if you apply 5V to the 4K7 to thebase of Q23 does the relay operate?Mark On 28/02/2014 08:06, jerry@xxxxxxxxxxxxxxxx wrote:Thanks for your help Mark. The software is displaying transmit and itisin transmit. The base of Q23 is .652. The voltage on pin 5 is 2.24 and when I push the PTT it goes to 0. Jerry K5LRU Harwood, Texas-------- Original Message -------- Subject: [minima] Re: Stuck in Transmit From: Mark G0MGX <mark.g0mgx@xxxxxxxxx> Date: Fri, February 28, 2014 1:55 am To: minima@xxxxxxxxxxxxx So is the software displaying TX and the relay in TX also or just oneofthose? What is the voltage on the base of Q23 now? What's the voltage on pin5?How do these change when you press the PTT? If the software is displaying TX then the pin 5 is being pulled LOW externally. If the software is in RX but the relay in TX (this was my problem) then it's just a level / voltage problem. If you physically connect the base of Q23 via 4K7 to +5 does the relay work? If you explain (probably again - sorry) exactly what the scenario is then I will try and help you debug it. M On 28/02/2014 07:37, jerry@xxxxxxxxxxxxxxxx wrote:Ok, I just put the 10k between the 5v pin on the digital board topin 5on the digital board, still in transmit. Jerry K5LRU Harwood, Texas-------- Original Message -------- Subject: [minima] Re: Stuck in Transmit From: Mark G0MGX <mark.g0mgx@xxxxxxxxx> Date: Fri, February 28, 2014 1:29 am To: minima@xxxxxxxxxxxxx That's not a pull-up that's a pull-down. The PTT switch will pulltheline to ground, I can't find the post but I think we said youneeded topull high normally and then use the PTT switch to pull low whenpressed.When in RX the line should be HIGH so if you have put a 10K togroundthat will pull it LOW. Your 10K needs to be from pin 5 to the 5V line. M On 28/02/2014 07:25, jerry@xxxxxxxxxxxxxxxx wrote:4.7k and added a 10k pullup resister from pin 5 on the micro to ground
