txaviator
Well Known Member
Evening, everyone. I have a Val Com 760 TSO comm radio that was working great. However, I decided to change the push-to-talk switches, along with the respective cords going into the panel.
Now the PTT buttons are not working. If I am not mistaken, a PTT switch is simply a momentary switch that closes a connection when activated, and allows headset communication. Everything was soldered, and then buttoned up with heat shrink over the connections.
Here's the very strange part: I can plug in my headsets (I tried two differerent sets to be sure I didn't have a bad microphone in one of them); I can hear the tower just perfectly, but when I hit the PTT, I can hear it activate like I am communicating, but the tower cannot hear my transmissions. Even stranger, I laid my portable tranceiver in the seat bedside me. When tuned to the same tower frequency, every time I press a PTT switch, I can see "RX" (receive) show up on the screen of the handheld. So, it's as if I am somehow transmitting, but my voice cannot be heard. In other words, I break the frequency but nobody can hear me?
I was careful to just make my new connections behind the panel, in the same locations as before. I simply changed out the PTT switches themselves, and their respective cords. What I did NOT do, was carefully observe that I reconnected my two new PTT wires to the exact specific wires behind the panel that they were soldered to before. My reasoning was again, that a PTT is simply an interuption/ground, so there isn't really any polarity. Since the PTT switches don't have any polarity either, I didn't see where it would matter. I just soldered one lead out of my PTT to one of the leads I cut off from the old PTT, and then connected the other.
Any suggestions? Again, I find it strange that my handheld shows receive, but nobody can hear me. I thought maybe I now have TWO bad headsets, but I just can't see that being the issue. They are both relatively new David Clarks, with very limited use and very good storage/care.
Any ideas to help figure out my frustrations? Thanks in advance!
Now the PTT buttons are not working. If I am not mistaken, a PTT switch is simply a momentary switch that closes a connection when activated, and allows headset communication. Everything was soldered, and then buttoned up with heat shrink over the connections.
Here's the very strange part: I can plug in my headsets (I tried two differerent sets to be sure I didn't have a bad microphone in one of them); I can hear the tower just perfectly, but when I hit the PTT, I can hear it activate like I am communicating, but the tower cannot hear my transmissions. Even stranger, I laid my portable tranceiver in the seat bedside me. When tuned to the same tower frequency, every time I press a PTT switch, I can see "RX" (receive) show up on the screen of the handheld. So, it's as if I am somehow transmitting, but my voice cannot be heard. In other words, I break the frequency but nobody can hear me?
I was careful to just make my new connections behind the panel, in the same locations as before. I simply changed out the PTT switches themselves, and their respective cords. What I did NOT do, was carefully observe that I reconnected my two new PTT wires to the exact specific wires behind the panel that they were soldered to before. My reasoning was again, that a PTT is simply an interuption/ground, so there isn't really any polarity. Since the PTT switches don't have any polarity either, I didn't see where it would matter. I just soldered one lead out of my PTT to one of the leads I cut off from the old PTT, and then connected the other.
Any suggestions? Again, I find it strange that my handheld shows receive, but nobody can hear me. I thought maybe I now have TWO bad headsets, but I just can't see that being the issue. They are both relatively new David Clarks, with very limited use and very good storage/care.
Any ideas to help figure out my frustrations? Thanks in advance!
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