US Call Prefix Scheme(s)

Most all are aware of the FCC broadcast call letter prefix rule wherein stations east of the Mississippi River begin with a W and those west of it with a K (with some grandfathered exceptions like WFAA in Dallas and KDKA in Pittsburgh).

Once upon a time (at least thru the 1960s) the FCC call letters issued in the land-mobile service followed a little bit of a scheme that would enable one to have a reasonable idea of the geographical origin of a station heard. It all hinged on the second letter of the three prefix letters with them very often corresponding to the ham call areas.

     ham call area:   1   2   3   4   5   6   7   8   9   0
     2nd ltr in pfx:  C   E   G   I   K   M   O   Q   S   A

A cursory inspection of the calls for these paging station audio clips will show that it held fairly well. I'm not sure when it was instituted/ended. However, since the early 1980s 4-letter prefixes have been issued in the land-mobile services for new (and some renewed) stations so any such "clues" no longer exist for those cases.

Of course, with some of the less-clearly enunciated IDs from the fire/police/business dispatchers/mobiles it was often difficult to distinguish the B/C/D/E/G/V, F/S, etc. That's why the Morse-coded tones were more reliable (if not too fast or made using a defective mechanical-keying device!) Many two-way services now have their IDs encoded in a digital burst at the beginning of each transmission.

  This might remind some of the 1958-62 FCC use of their Radio Inspection
District number as part of the prefixes for the 27-MHz Class D CRS call
letters.  Here in south Texas that had 9W#### (later 9A and 9Q).  Soon
the emerging nations of Africa noticed that these were the same as those
that the ITU had allocated to them!

  To rectify that, new/renewed licensees were then given a three-letter
prefix beginning with K followed by four digits.  In this the 3rd letter
of the prefix was keyed to the 24 FCC RIDs - with this area ending up
with things like K-T####.  By the mid/late 1960s that middle letter
(changed yearly or after 9999 was reached) was already up to around Q
and that system soon seemed doomed to falter.

  In the mid 1970s those operators in too much of a hurry to use their
equipment before the "in-box" FCC Form 505 had been sent in with $20 and
answered were permitted to concoct their own "temporary" call signs
incorporating, of all things, their name initials and ZIP code!  Lots
of K---78228 soon in these parts.

  The FCC eventually solved the "problem" by simply not bothering to
issue/renew any more licenses/calls for the service.  Anarchy had won.


Page modified November 7, 1997
May 22, 2012