The International Cessna^® 170 Association

Is there a problem with a KX125 comm/nav relative to higher frequencies? I have one in the C-170A that I recently bought and someone mentioned that I might not be allowed to use the transmitter without an FCC exception or something like that?

The KX-125 is a modern digital nav-com, self-contained with no external nav indicator needed. I've never heard about any frequency problems with it. Except maybe in the future,when they go to that proposed new frequency spacing-- then we'll all have to pony up some big bucks for new radio's!
Whoever you talked to might have been thinking of the old KX-145. It was a nav-or-com radio, you can either use the nav or the com, just not both at once. It's old enough where it's probably a 360 (or less!) channel com, with the transmitting frequencies not precise enough to meet the newer FAA/FCC spec's. In other words,for example on 123.0, it'll bleed over onto 123.025 or 123.05.
Depending on the frequencies you use in your everyday flying, it might give plenty good service, it's just not strictly legal. They are approved to have installed, but I think they have to be placarded "nav only". Or at least "not approved for transmitting" or something like that.

Eric

The KX-125 is one of King's current production models in the "cost effective" category. I seriously considered one last year. There's nothing about this model that should require any sort of "waiver" or "exception". The only paperwork hoops should be the 337-type ones on getting it installed - which in your case "should" already be done.

Go fly and use it. There are radios still flying out there (probably illegally) with far less capability than the KX-125.


Here's the link to King's product page:
https://www3.bendixking.com/static/cata ... jsp?pid=85

Gee my airplane has a KX125 (which I think is great) AND a KX145

I like the 145 as a backup, in fact I bought anuther on Ebay cheap so I wouldn't have to worry about it going out. I must confess that I've transmitted on it. The day before we were to leave WA for AZ a few years back the 125 went out so I had to use the 145 to get home to AZ. Works great.

Thanks for the replies. Perhaps the person I was speaking with mistakenly was thinking of the KX145. This forum is a great way for those of us with less experience to tap into the vast resources of knowledge out there. Many thanks again--best wishes to all for a prosperous and Happy New Year.