Re: Tighter DAs at night than day

[Dan.Strassberg@att.net]

Decades ago, KFAX 1100 in San Francisco, like many heritage Class Ds on 
the west coast, was a limited-time station. (WTAM did not operate 24/7 and KFAX 
would sign on when WTAM was off--usually from something like 10:05 PM to 2:00 
AM Pacific time. KFAX would also sign on at Cleveland sunrise, which was never 
later than 5:00 AM Pacific time.) KFAX operated for years with 1 kW-L from a 
rooftop antenna somewhere in downtown San Francisco. Then, years before the 
clear channels were broken down and KFAX was granted 50 kW-U DA-1, KFAX was 
granted 50 kW-D DA-D, but its operation before San Francisco sunrise and after 
San Francisco sunset was still limited to 1 kW ND from that same rooftop. So 
KFAX or maybe a similar station, KFVD 1020 in LA, or maybe KXL 750 in Portland 
OR, might have been the first station or stations to operate with 50 kW DA-D 
and 1 kW ND at night.

Higher power nights than days is now quite common. KFMB 760 in San Diego runs 5 
kW-D/50 kW-N DA-N. The reason that KFMB is stuck with 5 kW D is that the cost 
of buying KBRT 740 in Avalon and taking it dark is prohibitive. When the clears 
were broken down, what was then KBIG applied to move from 740 to 830. It would 
have been a phenomenal facility--the day site could have remained on Catalina 
and the night site would have been on the mainland--but the FCC granted 830 to 
another applicant.

If you've been in LA, you know that KCBS is local there at night. However, KBRT 
has an authorization for a few watts at night. I understand that they use it 
too--to cover Catalina Island. KCBS's signal there must be close to 25 mV/m on 
many nights, so KBRT probably doesn't even cover the entire island at night. 
HUGE daytime signal though--at least until KCBS's daytime skywave starts to eat 
it up toward dusk.

--
dan.strassberg@att.net
617-558-4205
eFax 707-215-6367
> <<On Wed, 05 Mar 2003 21:09:43 +0000, Dan.Strassberg@att.net said:
> 
> > back west to a site about 3 km north of the old Livingston site but
> > with seven towers days and four night using 8.5 kW-D/5 kW-N DA-2.
> 
> Which reminds me of something I noticed last year in Dallas.  There
> are a number of stations in that market that have significantly
> stricter patterns during the day than they do at night.  This is a
> relatively uncommon situation, but becoming more common recently as
> the envy factor causes stations to build out ill-considered daytime
> power upgrades while leaving the night facilities unchanged.  Can
> anyone think of another example?
> 
> I recall that the NRC's odd antenna mode code scheme includes a code
> for DA-D/ND-N operation, so there must be some station somewhere which
> is doing that (any of them fulltimers?).
> 
> -GAWollman
>