[TowerTalk] 160 radials

[jimlux]

left a word out, which makes it confusing.. see below

jimlux wrote:
> 
> 
>   BC stations use quarter wavelength
>> (mechanical quarter wave) radials because 120 of them will provide a low
>> impedance when placed in parallel and current share well since each are
>> a high impedance. 
> 
> 
> One wants to be careful about reading too much into broadcast practices.
> a) it's a different frequency
> b) they're interested in having a very

*stable amplitude*

> radiated ground wave for regulatory reasons

For one thing, lots of radials makes you insensitive to things like how 
recently it rained.  If you're doing proof of performance tests and 
such, measuring a particular field strength at a particular distance is 
important for licensing.  You don't want either too high (the FCC makes 
you turn down your power so you don't interfere) or too low (you don't 
get the required coverage contour).


> c) they have different cost/benefit analysis assumptions than the usual ham.
> d) they have various preferred implementations from a regulatory standpoint.

If your implementation is "standard" then less engineering or test work 
is required to prove that it "works as required"
>