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At 03:13 PM 5/5/97 +0000, you wrote:
>        I would guess that WPTF must be the oldest full-power Class II (now
>Class B) station on 680, as it operates non-directional daytime and with
>only two towers at night. I wonder why WPTF never got Class I-B status,
>especially as it's so far from San Francisco.

Well, the reason is unlikely to be tower height or antenna efficnecy. The
FCC has granted waivers of the antenna-efficiency requirements for Class I
stations. The fabled KGO signal originates from 1/4-wavelength towers and
KGO was a IB. (Meanwhile KCBS, a Class II, uses 3/8-wave towers, which,
because they're 500' high, meet the FCC's requirements for Class I stations.
The requirement is 225 mV/m unattenuated @ 1 mile or 500', whichever results
in the shorter tower--an obvious concession to the FAA.) WBBR uses a
half-wave tower during the day, but at night, that tower is only one of four
in the array. The other three are only a little over 1/4 wavelength. WBBR's
nigttime antnenna efficiency (210 mv/m unattenuated @ 1 mile) does not meet
the requirements for Class I stations.

- -------------------------------
Dan Strassberg (Note: Address is CASE SENSITIVE!)
ALL _LOWER_ CASE!!!--> dan.strassberg@worldnet.att.net
(617) 558-4205; Fax (617) 928-4205