[TowerTalk] 160m antenna

[jim Jarvis]

Since I'm coming in late on this, I'll keep it brief.

a)  "many old AM Broadcast Towers"  did NOT use "slant feed".
	in fact, the FCC almost universally required series fed systems,
	and where they didn't, a more typical shunt feed system was used.
	There MAY have been one or two using some sort of slant system,
	in deep history,  (KDKA, WLS?)   but I've never seen one, nor did 
	one appear in broadcast literature in the time I was involved in the industry.   

b)   A "half sloper" is actually a slant feed system for the tower, whether
	you want it to be, or not.   Which is why half slopers have such a varied
	and checkered historical review.

c)  If it were me, I would put out proper radials on the 90' tower and shunt feed
	the thing, and forget about trying to put wires close to towers.   Unless you did
	a dipole... but both your towers are way too low for 1.8MHz dipoles to work 
	except in NVIS mode.  

d)  The OTHER possibility might be to use both the 60 and 90' towers, to support
	a folded vertical dipole.   See the YCCC site for description of this "U" shaped
	antenna.    Depending on how far apart your towers are, there may be opportunity
	to get the high current portion of this system 30' or more in the air,  and stand it off
	from the tower by a useful distance.   

e)  The final idea is this--there is a system which puts resonant radials out from a tower,
	at a distance down from the TOP of the tower.   They are fed from the center of the coax,
        and the tower is connected to the shield.

	I'm not sure what it's called, but it was some sort of "inverted sloper"  or "reverse ground plane" 
        kind of language.   Whether it's effective nor not appears to depend on the yagi on top of the tower, as it
	functions as loading.   

	I've used one of these, in contests, and it appeared to be quite effective on deep Asian and PAC paths from
	the east coast, as well as into EU.   I believe that system used 6 "radials",  10' down from the tower top,
	with a 3 element 40m yagi on top.   

	Analytically, this looks to me like a more symmetrical variant of the 'half sloper', with the high current
	portion at the top.   

N2EA