Finding Yaesu 2900R COS/COR line (Carrier Operated Switch / Carrier Operated Relay)

[@bsd9244]

This video helped me locate COS in my FT-2980R which I used to build an Allstar remote base. I posted a video showing how I did this on my channel and referenced your video in my video and notes, I hope that's ok. Thank you for posting this is was a big help :)

[@EphraimGariguez]

Thanks for the feedback

[@SparkyRF]

Just wanted to mention that the COS signaling is a positive voltage, NOT negative. Notice that the meter probes are plugged in backwards on the meter, itself. So, no carrier (COS inactive) is 4.8V, when active (carrier present) is near 0V.

[@africantwin173]

Would this also work for the FT-2980. I havent found any service manuals online.

[@EphraimGariguez]

Most probably