J.J. Jackson at WTUR

[markwa1ion@aol.com]

Railroad tracks would make a fairly decent ground, but a crummy 
antenna.  Horizontal radiators are poor in the AM band.  With any 
antenna or ground system, it's only the first few wavelengths that 
contribute to radiating a signal.  After that, most of the signal 
voltage is gone.  1000 miles of wire (or track) is little different 
from 1000 feet.  RF does not act like DC or mains AC.

As a serious ground, 120 quarter-wave radials PER TOWER, as typically 
used by better AM installations, is the way to go.

The best "get-out-ability" AM stations like Boston's WBZ and NYC's WCBS 
are running 50 kW to tall towers and extensive radial grounding systems 
in coastal salt-water marsh.  If hearing these nationwide is a 
challenge on ordinary receivers (we're not talking R-390A's and beach 
Beverages), then 20 watts connected to ANYTHING, including a wire to 
the moon, isn't going to be heard too far.

Hooking a carrier current rig to tracks or several hundred feet of wire 
between tall buildings will certainly get it to more places, but I'd be 
surprised if any of those places were beyond 50 miles.  Maybe with the 
right skip and/or waterpath, 200-300 miles at best.  The higher end of 
the AM dial, rather than 560 kHz, would actually be better in terms of 
skip.

For the guy who attended Tufts in the late '60s, I wonder if you knew 
two of my ham buddies who went there around then - Phil Schoenheiter 
(N1PZU) and Chuck O'Neal (K1KW, ex-WA1EKV).  They were E.E. students 
who may have been involved with the Tufts ham club (W1KN) and perhaps 
the broadcast operation as well.

The late Gordon Nelson had told me about students at MIT's carrier 
current (640) hooking up a good antenna once.  It was heard at least as 
far as NH and metro-Worcester (but by DXers, not casual listeners).  As 
far as average-listener quality range, I think the Fenway Park area is 
about as far as it got.

I went to Northeastern U. in the late '60s and early '70s.  Before WRBB 
(originally 91.7, later 104.9) came on, there was carrier-current 
WNEU-560.  Its coverage, even around campus, was spotty and by the time 
you got "a frisbee toss away" to student apartments on the north side 
of Fort Hill (just across the Columbus Ave. RR tracks), it was buried 
under the WGAN/WHYN mix.

Mark Connelly, WA1ION - Billerica, MA

<<
"aerie.ma@comcast.net" wrote:

I was an undergraduate at Tufts 1966-70. WTUR was carrier current in the
dormitories, on 560 kHz if I recall correctly. You could barely hear 
them in
the parking lot outside the dormitory. I do seem to remember that they 
did
put an FM transmitter on the air that had a bit larger range. I think 
it was
on 88.3 Mhz. The range was barely the entire campus, however. I lived a
block away from the campus and could not receive it there, and it did 
not
interfere with WTBS (at the time) on 88.1 mHz. This was distinct from 
WMFO
which came along later. I wonder if WMFO was incorporated in 1970 to 
make it
the University's responsibility, rather than a "student club" as WTUR 
was.
>>
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