WLLH-AM Lowell Transmitter On-Air (With IBOC?)

Dan Strassberg dan.strassberg@att.net
Mon Jan 8 16:24:45 EST 2007

It's possible that WAMG's complex five-tower array, diplexed at night with
1060 and not broadbanded at either frequency, makes IBOC infeasible on the
890 signal. WHYN in Springfiled was deemed inapproptiate for IBOC, in part
because of the narrow bandwidth of its electrically short towers. Seattle's
950, which is diplexed with 820 and not far away on Vashon Island from 570,
710, 1000, and the 1090/770 diplex, was deemed unsuited because all of the
filtering to suppress intermodulation with the nearby signals was already
too complex. (With the exception of 570, all of the Seattle stations
mentioned run 50 kW-D and four of them also run 50 kW at night.) It would
not surprise me to learn that New York's 1010 and 1050, Phildelphia's 1060,
and South Jersey's 1040 will never run IBOC. Every AM must be evaluated
separately. Also, are you sure that the hash you heard was, indeed, IBOC?
You mentioned hash from 1350 to 1430. That frequency range is not
symmetrical about 1400. IBOC hash is supposed to be symmetrical about the
carrier frequency. If it is not, the system works poorly or not at all.


Dan Strassberg
Fax: 1-707-215-6367

----- Original Message -----
From: "Laurence Glavin" <lglavin@mail.com>
To: <boston-radio-interest@rolinin.bostonradio.org>
Sent: Monday, January 08, 2007 2:13 PM
Subject: WLLH-AM Lowell Transmitter On-Air (With IBOC?)

> Just to acquaint BRIGgers in other pahts of New England:
> WLLH-AM 1400 is licensed to Lowell, MA, and if you went by the
> fcc.gov's website, you'd never know there's a 70-year-old
> experimental authorization for a synchronous operation in Lawrence.
> As Mark Watson has pointed out, one of the transmitters (lately
> Lowell) can go off-the-air and the other covers the area at least
> during the day.   Well, a couple of weeks ago, the Lowell transmitter
> powered down making the "experimental" antenna the WLLH tower of record.
> My travels took me to Lowell today, and just for fun, I went over to the
> transmitter site, and lo and behold, WLLH Lowell was on-the-air...
> not only that, but there was significan hash from 1350 to 1430 (so
> you had WLLH hash fighting it out with WXKS hash).  It's possible
> that the engineers had taken WLLH/Lowell off-the-air to install the IBOC
> system, which raises deux questions (a little French lingo): if this
> hash is due to HD AM radio facilities being installed, have they yet
> done so at the mother ship, WAMG-AM 890 COL Dedham?  If not, why
> would they do so at a satellite outlet and not near Boston...please
> anyone in the western suburbs of Boston,check to see if there's hash
> where you are at 860,870,880,900,910 or 920.  Second question: considering
> that you have two stations transmitting on the same fequency, with about
> the same power output, if one is running IBOC and the other isn't
> (and WLLH/Lawrence is not causing interference with the 1380 and 1420 NH
> stations I can receive) what would a possible HD AM receiver do if it's
> a station that's both IN IBOC mode and NOT in IBOC mode.  If you're
> mainly picking up WLLH/Lawrence, but SOME energy from WLLH/Lowell,
> will it take the digital signal from the latter and discard the former?
> Of course, if they install IBOC in Lawrence, then all of the above is
> irrelevant...it may be irrelevant anyway;  what's the audience for network
> sports talk in Lawrence or Lowell anyway?
> --
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