[BC] KKGM

[PeterH5322@aol.com]

>>What is the efficiency of a 263+-degree radiator SUPPOSED to be (in 
>>mV/m/kW 
>>@ 1 km), assuming a normal (120 quarter-wave-radial) ground system?  It is 
>>presumably less than the efficiency of a 225-degree radiator with the same 
>>ground configuration. I have never seen theoretical efficiencies for 
>>standard series-fed radiators of heights greater than 225 degrees 
>>(approximately 440 mV/m/kW @ 1 km). Also, what does the vertical-plane 
>>radiation pattern look like?
>
>A quick NEC analysis of a ~264 degree vertical radiator shows an FCC 
>efficiency of about 325 mV/m for 1 kW at 1 km. 

And ...

If that 263 degree radiator was to be sectionalized, it would be 131.5 
over 131.5, or better yet, 143 over 120.

Such a sectionalized radiator could be expected to have an efficiency of 
over 430 mV/m/kW at 1 km, and virtually no "skylobe".


But ...

One very old station (a well known former 3-letter call) had moved to a 
super-tall radiator, one which certainly far exceeded 180 degrees, and 
which was really more like the 260 degree radiator mentioned above.

It is apparently now back at its original radiator, about 185 degrees, 
where it should have an efficiency of about 380 mV/m/kW, but the FCC has 
assigned an efficiency of about 315 mV/m at 1 km, which number is 
certainly consistent with Richard's 325 number for a super-tall radiator.

Apparently, it became grandfathered at the efficiency of its interim (not 
original) tower.