[BC] WLW--when it was 500 kW

[Dan Strassberg]

Rob Atkinson wrote about how when WLW ran 500 kW in the '30s, its groundwave
coverage extended all the way to Canada.

Certainly not hard to believe, given that it's only, what? 250 miles or so
from south to north across Ohio and then another maybe 50 miles across Lake
Erie. Remember, 700 is a lower frequency than WBZ's 1030 and the soil
conductivity in most of Ohio is quite good.

However, pre NARBA, CBL was on 690--or so I've been told--and WLW had to
directionalize to the southwest to protect CBL from wicked first-adjacent
intereference. No, WLW didn't use two Blaw-Knox diamond towers. Scott Fybush
undoubtedly knows what kind of tower WLW used as the other element in its DA
and maybe even the distance of that tower from the Blaw-Knox. I've never
seen a polar plot of the pattern, but my guess is that the minimum toward
Canada wasn't particularly deep--probably the equivalent of 50 kW ND from
the half-wave Blaw-Knox tower. If so, the radiation maximum to the southwest
could still have been equivalent to about 1 megawatt or in the neighborhood
of 10 V/m at 1 mile--significantly more than the strongest 50 kW directional
signal in the US today--WWJ with almost 8 V/m @ 1 km (inverse-distance
field) to the north at night from a six-tower array--of which only two
towers are near half-wave. Still, that's equivalent to more than 350 kW ND
from a half-wave tower and almost twice as much from a minimum-efficiency
stick.

--
Dan Strassberg, dan.strassberg at att.net
eFax 707-215-6367