[BC] XETRA - MIGHTY 690 Los Angeles.

[PeterH]

On Feb 18, 2010, at 8:31 AM, Rich Wood wrote:

> I think I remember the pattern as claimed on
> some promotional material which made it look like a figure 8 with the
> Southern lobe pulled in.
>
> The new owners have returned it to being a Mexican service station
> and don't care, after all these years, about reaching Los Angeles. So
> it makes sense that the new array favors Baja.

Three incarnations from two sites.

Two day patterns; two night patterns.

More than 50 kW is only possible for a Class I, now Class A station,  
and then only during days.

My take on it is the second incarnation of the day pattern favored  
local and Baja at the expense of Los Angeles, and 77 kW into that new  
day array resulted in the field strength in Los Angeles being about  
the same as the field strength of the old day pattern.

The old night pattern is not shown in the system it did indeed favor  
Los Angeles at the expense of Baja, and is probably what gave *Mighty  
Six-Ninety* its claim to fame.

The new night pattern favors Baja at the expense of Los Angeles.

So, what the owners did, over time, when they moved the Tx to  
Rosarito was to make the patterns favor Baja, which was their  
business strategy, while accommodating Southland listeners at least  
during days.

Nights is a whole :nother matter, and the new night pattern also  
reduces first-adjacent channel interference to San Francisco:s 680.

Remember ... 690 was never a Class I-A, defacto or otherwise, it was  
and is a station which is inferior in class to Canada:s 690 which is  
indeed a I-A.

Remember also ... 680 was originally a Class I-A, albeit a defacto one.

Consequently, 690 should have protected 680:s primary and secondary  
service areas at night, but it never did that until the present night  
array at least mitigated that interference, somewhat.