About 4 years ago, my crystal clear radios started to get muddy and noisy, both receiving and transmitting. I had to abort some flights as I was unreadable in some cases. It was very intermittent though so very hard to track down. Each time I thought I'd found and fixed it, it was back a couple flights later.
Took me a year of fooling around to discover that something was going bad inside the old intercom. That replaced, things were back to normal for the most part but I had a different noise intermittently again.
I was up flying this morning and had this noise back again. Moving the headset jacks slightly cleaned it up as usual but I know everything there is 100% and brand new. Ticked off again, I happened to move the low voltage warning buzzer wires which run very close to the headphone jacks/wires- problem solved. If I moved them close, noise was there, moved them away, gone. Did it 5 times to verify.
I unplug the white connector when I work on the plane with the master on to avoid listening to the buzzer. Each time I reconnect, the wires here are in a slightly different place which explains the intermittent thing. I've tucked the wires up and away now as shown here.
There is no current flowing through these wires unless the buzzer is on so I never even thought of this before as being able to cause a problem like this. The buzzer probably has a small coil of wire inside it. Must be some odd form of capacitance coupling going on when the wires are very close.
I learn something new every day...
Took me a year of fooling around to discover that something was going bad inside the old intercom. That replaced, things were back to normal for the most part but I had a different noise intermittently again.
I was up flying this morning and had this noise back again. Moving the headset jacks slightly cleaned it up as usual but I know everything there is 100% and brand new. Ticked off again, I happened to move the low voltage warning buzzer wires which run very close to the headphone jacks/wires- problem solved. If I moved them close, noise was there, moved them away, gone. Did it 5 times to verify.
I unplug the white connector when I work on the plane with the master on to avoid listening to the buzzer. Each time I reconnect, the wires here are in a slightly different place which explains the intermittent thing. I've tucked the wires up and away now as shown here.
There is no current flowing through these wires unless the buzzer is on so I never even thought of this before as being able to cause a problem like this. The buzzer probably has a small coil of wire inside it. Must be some odd form of capacitance coupling going on when the wires are very close.
I learn something new every day...