Duplicate station on VHF - is there a way to delete it?

[Grec]

I have no idea how this happened, but I ended up with two channel 21's on my ICOM 330 VHF.

One channel 21 displays normally, the second one says "21" along with "DUP" in the upper right corner of the display. Does anyone know how to delete the duplicate channel 21? I looked through the manual, but found nothing related to adding or deleting a channel.

 

[techmitch]

If all else fails, i.e. someone doesn't chime in, or contacting ICOM doesn't yield any results, disconnect both the power and ground and connect them to a 12v light bulb for a few as to deplete the internal capacitor storage if it has one, which it very well may have.

 

[hughespat57]

It’s not duplicate
It’s “Duplex”
21 in international waters is a duplex channel meaning for ship to coast operation. Ship transmits on one frequency and receives on a different.
In US channel 21 is simplex transmit and receive on same frequency.

Look for US vs International mode

 

[Grec]

It’s not duplicate
It’s “Duplex”
21 in international waters is a duplex channel meaning for ship to coast operation. Ship transmits on one frequency and receives on a different.
In US channel 21 is simplex transmit and receive on same frequency.

Look for US vs International mode

Wow! Thanks for that information. That has to be it!

 

[Grec]

It’s not duplicate
It’s “Duplex”
21 in international waters is a duplex channel meaning for ship to coast operation. Ship transmits on one frequency and receives on a different.
In US channel 21 is simplex transmit and receive on same frequency.

Look for US vs International mode

Okay, so I stopped at the boat to see if the radio was set to International. It was set on USA, but I realized that it is not channel 21 that shows up as a duplex channel on my radio. It is channel 20.

I also found a channel list in the manual, and it does list channel 20 as a duplex channel in the US. What's odd though, is that it's never been like that on my radios in the past. I know because if I wanted to hear a specific Coast Guard notice to mariners, I've always clicked up 6 stations to get from 16 to 22 . Now I click up 7 stations to get to 22.

Is this configuration something new?