FTM-350 and Right Side Squelch or Static Issue

[Wise87]

Something strange is happening today with my FTM-350. It’s been running great all week and today on the way home I noticed APRS was not updating like it normally does. I could see the signal strength meter was constantly indicating a signal and not allowing for the radio to beacon. I adjust the volume to hear what sounded like constant static on 144.390. I made a recording of what is going on in the attached zip file. If you noticed on the left side, I don’t have this problem. Both sides have the squelch adjusted the same. When I use the right side, I get no APRS information but the left side works like a charm. Also I don’t have any issues with any of the other channels I have programmed. Any suggestions?
Thanks
Dan

 

[SR385]

Use the left side

Actually seriously, the receiver designs are different on each side with the left as I recall having a more selective design. I *think* the left was triple conversion with the right was dual?? Moleculo will chime in I'm sure.

With different IF's, interference can affect each side differently.

 

[Moleculo]

According to the manual, the difference between the left and ride side is the IF bandwidth. Actually the right side has a narrower IF bandwidth. It doesn't show any difference between the circuit types (single, double, triple) on each side.

I've seen weird stuff like this in other dual receiver radios also. It might have something to do with the IF, but I've always suspected that there might be other unpublished differences in the VFO's that they don't tell us about. SR385 is right...just chalk it up to that and change the APRS to the other side.

The other thing you can try is to change menu G07 - Operation Mode under the SYSTEM group to "B" to see if that changes anything. That changes the CPU clock frequency. I doubt that will change the behavior that you're describing, but it's worth a try.

 

[Wise87]

I'll give it a try. Today I went on a road trip with APRS on the right side again. About halfway into my 40 mile trip the static interference returned like in the video and the signal was unable to transmit. I will try the left side next time but I should be able to use either side.

 

[doctordave]

Dan,

Curious how the right side audio is doing. I had persisting (R) radio audio problems....sent my radio back and should be receiving the replacement FT350 tomorrow. I'll let you know how that unit performs.