Title: V4 issue
Post by: WD8BXS on 05. June 2018, 17:58:48
I am working on a fellows V4, when you plug in the mic, the red and green LED's are flashing, transmit is pulsing on and off.
If you Press PTT, then it goes into transmit. When you release it starts pulsing again.
If you remove R8, the pulsing stops and you are able to PTT again.
Any ideas??
Chuck |
Title: Re:V4 issue
Post by: DF8OE on 05. June 2018, 18:17:31
It looks like the mic is pulling down PTT a little bit even if it is not pressed.
Three solutions:
1) use another mic
2) look what is tearing down PTT in microphone
3) add a pullup to 3.3V on PTT line that provides clean HIGH on PTT when not pressed
vy 73
Andreas |
Title: Re:V4 issue
Post by: WD8BXS on 05. June 2018, 19:00:42
Tried another mic,
If I use a jumper, the PTT works fine .
Why then when I remove R8 does it work fine? Doesn't that eliminate the PTT line as the problem? |
Title: Re:V4 issue
Post by: DF8OE on 05. June 2018, 19:32:51
No.
disconnect PTT in cable and the problem will be gone, too.
vy 73
Andreas |
Title: Re:V4 issue
Post by: WD8BXS on 05. June 2018, 23:04:10
Thank you, I added the pull up resistor and that took care of this issue.
Thanks again,
Chuck 73 ! |
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