I sometimes scan various bands on my Kenwood F6A, to discover what's on the air, and came across 300.125 MHz, or very near that.  I found voice transmissions going on during the late evening.  It could be occurring during other times, but it seems consistent between 10pm and Midnight.  There are Spanish speaking men and woman have very brief transmissions with other.  I do not understand enough Spanish to know what they are saying.

What seems unusual, to me, is the type of transmission, and the fact that there is no record in the FCC ULS of any assignments on or near that frequency.  The ULS only has two listings nationwide between 300 and 301 MHz, and they are both inactive licenses.

According to the frequency spectrum allocations, this frequency is allocated for mobile, mobile satellite, or fixed; and it is government exclusive.

The transmissions, as I mentioned, are brief, and there are, at least, 4 or 5 people.  Each transmission ends with a quick burst of three DTMF-like tones, which, together, last only about half a second.  The people seem to be coordinating something.  It seems more like information being passed, rather than casual talk.

Another thing about the transmissions is that they are sometimes distorted, as if the mode cannot be distinquished by the radio.  Sometimes they come in well using FM, and other times they can be heard well using AM.  The signal appears to zero beat on 300.125 MHz.  I have wondered whether I am picking up a harmonic frequency.  I have tried various multiples or fractions of the frequency, and have not found it elsewhere.

The signal at my house, near Patterson and Hollister, is very strong.  In fact, if I use the radio's attentuator, the signal is still full scale.

Has anyone else come across this?  Would someone else try listening, to see whether they receive it, or understand it?

---Michael, NO6O