[BC] Part 15 radio station

[Tom]

Try this one -

A fully compliant ground-mounted 100 mw TX with the 9-foot whip... and a 
*buried* quarter-wave ground radial system... the whole 120 radials 
thing.  Which, being buried, becomes the GROUND, not the ground lead... 
which is that piece of 2" copper strap sticking up.

Next, add, at roughly a half-wave out, a roughly quarter-wave-tall tower 
- NOT CONNECTED IN ANY WAY to the part 15 TX.

I tried this with a NEC-2/miniNEC model.

Not sure I believe the results... especially with that second, unfed, 
totally unrelated, tower...

Can you say "virtual J-Pole"?  Is what it looks like, sorta....  Had a 
LOT of gain, and came out virtually perfect omni.....

Richard Fry wrote:
>> How about if the thing is simply bolted to the top of a tower with no 
>> ground wire at all?
>
> If the tower is grounded at its base, then the tower _is_ the ground 
> lead/wire.  If it isn't, the tower still is one arm of a dipole.  
> Either way the tower itself will radiate, unless the Pt 15 tx is 
> insulated from the tower.  Even then, the program and power wires 
> leading away from the tx will radiate unless they are decoupled for r-f.
>
>> I can picture one of those things on top of a 2,000' tower.  
>> Coverage, I'll bet!
>
> The elevation pattern of a vertical monopole of more than 5/8 
> wavelength wouldn't be optimum for producing groundwaves.
>
> RF
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-- 
Tom Spencer
PG-18-25453 (nee' P1-18-48841)
http://radioxtz.com/
Part 15 transmitters on AM 640 and FM 100.1