Please be kind to this newbie with my observation and question:
I am trying to operate in simplex. Here is what I noticed on the radio display; frequencies either display a +, - or nothing on the display. The frequencies selected by using the front dial that do not display the + or -, I can communicate in simplex, station to station. The other frequencies that display the + or - transmit on another frequency.
Why is this? Is it normal?
I assumed that a dialed frequency could be used in simplex. Is my assumption incorrect? Is there a setting on the radio that I can change? I reset the radio to factory settings and the results are the same.
Help?
There exist things called "band plans." These are "gentleman's agreements" that divide a particular frequency band up into segments for different purposes. Commonly, these are repeater inputs, repeater outputs and simplex operation. There are others, such as digital or RTTY modes, but for purposes of your question, we'll deal with just the repeaters and simplex.
Because these band plans have been in effect for quite a while, the radio manufacturers—iCom, Kenwood and Yaesu—have built the repeater offsets into their radios' firmware. This is why you are seeing + and - signs on your display when dialing to some frequencies. Those are set aside for repeater use. While you can use those frequencies for simplex by turning off your radio's automatic repeater shift, it's best to NOT use simplex on those frequencies because of the possibility of interfering with an existing repeater.
The band plans for the various bands in the US can be found at the ARRL website:
http://www.arrl.org/band-plan.
You can also purchase a nice printed guide that covers all the band plans from 160 meters up to 70cm:
https://www.niftyaccessories.com/bands_op_guide.php