[BC] Short AM Tower

[R A Meuser]

About 30 feet of top loading and a fat tower (2 to 3 foot face) will get 
the drive point impedance to a reasonable value. I would also agree with 
those who suggest a series fed radiator. The simplicity will help keep 
the station with a good signal after the engineers leave. It would be 
worth getting this all properly modeled first to optimize the tower size 
and loading.



Richard Fry wrote:
> Larry Lamoray wrote:
> 
>> Have a client trying to use a 100 ft tower for AM on 1230.
>> 200 feet is prohibited by local ordinance. :-((
>> Any suggestions as to how to make the best of a bad situation?
> 
> ______________
> 
> A quick look with NEC hints that a 100' monopole with 2' faces used with 
> 120 radials each at least 1/4-wave long could just make 241 mV/m at 1 km 
> for 1 kW of applied power if the total of the r-f ground and matching 
> loss was ~ 4 ohms.  The SWR bandwidth when optimized for 1230 kHz shows 
> to be less than 1.3:1 at +/- 10 kHz.
> 
> Adding some top loading would make it all easier.
> 
> Might be worth checking out with your consultant.
>