"Gary G" wrote in message
...
Is that legal?

No. The FCC rules call out specific frequencies for use in specific
situations, including air-to-air, air-to-ground, radio testing, etc. You
are not permitted to use, for example, a tower frequency that you believe to
be unused in the area for some other purpose.

Is it ok?

Define "ok". Many pilots use 123.45 as a "junk" frequency for the purposes
you mention, but it's not a permitted frequency. It's unlikely you'll
interfere with anyone else using that frequency, and it's unlikely you'll
ever get caught. But don't you think it would be better to stick to an
approved frequency?

(Let's assume your monitoring other freqs that you need to).

I have no idea what that has to do with it.

Pete