jmtillery said:
Thanks for all the comments. I knew the initial reason WLCY-TV was licensed to Largo was because of the short-spacing with WPLG-TV 10 Miami requiring WLCY-TV to locate its tower North of Tampa Bay, which created a city grade signal that fell short of Saint Petersburg.
What I don't understand is how channel's 10's licensee was able to convince the FCC to re-license the station to Saint Petersburg, even though channel 10 upgraded its signal, power and tower HAAT, which already had channels 38 and 44 leaving no locally assigned TV service to Largo. I. E., Largo's only local TV service was taken and given to a community that already had two local TV services - WTTA-TV 38 and WTOG-TV 44.
Normally the FCC will never allow any licensee to take a community's only primary radio or only primary TV broadcast service and re-license it to another community unless a substitute channel is proposed and used as a replacement for the channel vacating the community. Low Power service and translators do not count as local broadcast service due to the fact that these services are licensed as secondary radio and TV services.
This one
is awfully difficult to explain.
The channel wasn't in the original allocation tables. It was dropped in sometime between 1952 and 1965 - and allotted to St. Petersburg. Under current rules, channel 10 couldn't be allocated to St. Petersburg if there wasn't some site where it could operate at full (2,000'/316kw) facilities without interfering with WPLG and still provide a city-grade across St. Petersburg. Any station then built on the channel would have to provide a city grade across St. Petersburg and be at least 220 miles from WPLG.
At the time, a station's main studio had to be in the city of license, so maybe the station built its studio in Largo & had to change the COL to match -- but in the 1966
Broadcasting Yearbook the station's address is listed as 2429 Central Avenue, St. Petersburg. (maybe that was just a mailing address and the main studio was elsewhere?)
The minimum distance separation rules for analog have not changed since 1966 - it's still 220 miles for VHF stations on the Gulf Coast. So it's not a situation of the FCC changing rules to allow the station to move closer to St. Petersburg. (there does seem to be some kind of waiver in place as today, WTSP and WPLG are 219 miles apart. Maybe in the days before computers the calculation of distance was a bit less accurate!)
The issue seems to be the station's low tower. According to the 1966
Yearbook WLCY-TV's antenna was only 500 feet above average terrain - 149 meters. Using the FCC's coverage prediction curves (as converted to a web application on the Commission's website) 316kw/149m is predicted to provide a city-grade signal to only 40.36km, about 24 miles. The distance between the station's current tower and the "reference coordinates" for St. Petersburg is a bit more than 50km. Assuming the tower wasn't any further south in 1966 than it is now, WLCY-TV wouldn't have been able to provide a city-grade across St. Petersburg.
(under current rules I think the FCC would probably have made them put up a taller tower! There wasn't any kind of military aviation going on up there in the 60s that would have precluded a taller tower? It's even further from McDill AFB than the other Tampa towers.)
The station has since of course put up a much taller tower -- 458m. According to Curves the city-grade contour now extends out more than 62km, easily covering St. Petersburg.
As you say, under current rules they couldn't have gotten it reallocated
from Largo once they got it reallocated
to Largo. Seems to me that prohibition doesn't date back to the beginning though. For one example, the channel 6 station in Milwaukee was originally allocated to the northern suburb of Whitefish Bay. Sometime around 1960 they got the allocation changed to Milwaukee, even though that left Whitefish Bay without any channels and added a channel to a city that already had six.
(though the strange thing about that case was that the channel was allocated to Whitefish Bay in the first place because the city of Milwaukee was too close to an existing channel 6 station in Iowa; Whitefish Bay was just far enough further north to meet the spacing requirements.
But that policy should have prevented the allocation of channel 10 to St. Petersburg, because regardless of the tower site, the city of St. Petersburg isn't 220 miles from WPLG's transmitter. The channel could have been allocated to Largo, but not to St. Petersburg where it actually was allocated.
Obviously the rule changed sometime between 1956 and 1965.)