[BC] X-Band antennas

[Mark Humphrey]

Neal,

You aroused my curiosity (and I know which station you
refer to) so I just looked up the application.

True, the predicted coverage area will decrease, but
service population goes way up -- the new site is only
7 miles from downtown Philadelphia!

My guess is that the owner decided in favor of the
unipole, rather than insulated base series-fed, to
make it simpler to lease tower space to land
mobile/cellular tenants.  No need for isocouplers.

There is apparently a right-of-way limitation that
prevents 1/4 wave radials from being installed.  I see
the FCC flagged the application for that reason;
that's why it was amended to specify lower theoretical
efficiency, despite the increase in tower height.

So you are correct -- it probably won't cover the same
distance -- but the license value goes *way* up
because it becomes a defacto Philadelphia station. 
And, of course this change is "in the public interest"
because poor old Lindenwold, NJ finally gets a first
local service!  

Mark



--- "Neal Newman <groucho at skyweb.net>"
<reader at oldradio.com> wrote:

> I maintain several stations. One of them is  going
> under the following changes:
>   short towers moving to shorter towers
> 
> OK Guys, give me some figures on this one. This
> makes me sick and I need to 
> know if I'm wrong for feeling this way
> 
> A station is presently duplexed on a series fed
> tower with a complete 
> ground plane with the following:
> 
> Power: 10 kW, Non-Directional
> Tower Electrical Height: 110.7 Degrees; 54.87 meters
> RMS Theoretical: 319.5 mV/meter (per kW) or 1010.35
> mV/meter at 10 kW
> 
> Power: 1 kW, Non-Directional
> Tower Electrical Height: 110.7 Degrees; 54.87 meters
> RMS Theoretical: 319.5 mV/meter
> 
> The station is being moved over to its own tower,
> which is a 61 meter tower 
> as a unipole, and the ground plane is just short of
> a 1/4 wave closer to 
> 1/8 wave with the Following specs.
> 
> Tell me what I think. I already know the station
> will not cover anywhere 
> like it used to.
>

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