J.J. Jackson at WTUR
Jim
aerie.ma@comcast.net
Wed Apr 4 08:57:45 EDT 2007
I've wondered about the railroad tracks thing too. I have no recollection of
that at all, and since WMFO went on the air in 1970, I can't believe the FCC
had just "raided" them for the railroad track infringement. Besides,
railroad tracks are not continuous. There are insulators periodically to
divide the track into blocks electrically for the signal system to be able
to indicate where a train is.
I did not know your two ham buddies at Tufts, but I did have Organic
Chemistry lab across from Tommy Hadges, who was very active at WTUR and
subsequently one of the foundation group at WBCN. I wish I had kept in touch
because he'd certainly know about the railroad track thing.
-----Original Message-----
From: boston-radio-interest-bounces@rolinin.BostonRadio.org
[mailto:boston-radio-interest-bounces@rolinin.BostonRadio.org] On Behalf Of
markwa1ion@aol.com
Sent: Wednesday, April 04, 2007 8:51 AM
To: boston-radio-interest@rolinin.bostonradio.org
Subject: RE: J.J. Jackson at WTUR
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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