#40m #audio #help #qcx40 #sidetone #troubleshooting #qcx40 #sidetone #troubleshooting #40m #audio
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Good evening all.? ?
? ? ? ?On my qcx+ build which went well this time, I have an audio issue that I'm trying to debunk.? Everything seems to be working as it should - about 4.97 watts in the dummy load- no smoke .? ? But when I key down I get the noise I'm hearing sounds like a blown speaker.? ?It doesn't matter which speaker or headphones I have attached to it.? ?I thinking that there's an problem in the audio part.? ?? ? ? ?I'm definitely a rookie when it comes to electronics, but I can hold my own.? ?Any questions or suggestions? on where I should start to look at would be helpful . ? ? ?Thanks |
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Hi Darren. I would definitely first look at the audio muting circuit R60, D5 and Q7. You should see 5v on the gate of Q7 when the radio is keyed. If not there, look for it on the cathode first, then the anode of D5, and finally on pin 11 of IC3. Also, you didn't indicate whether you were using a dummy load or an antenna, but the symptom could also be caused?by RF getting back into the audio circuits. Hope that gives you a starting point to look at. 73 .. .Ron On Sun, Sep 3, 2023 at 2:43?PM Darren KN4WML <darrent78@...> wrote: Good evening all.? ? |
Darren KN4WML
Ronald Taylor