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Re: WLLH-AM Lawrence transmitter off-air
Yes. Both used to be rooftop installations, but a few
years back, the Lowell TX was upgraded to a conventional
antenna on the banks of the Merrimac not far from
downtown Lowell. I believe that, over the years, WLLH
has tried many different schemes for synchronizing the
frequencies of the two TXs. However, with advancements
in oscillator frequency stability, the "synchronization"
now consists of selecting a pair of crystals that are
pretty well matched. The synchronization used to be
better before the new Lowell TX went on the air. But
whenever the two TXs are on simultaneously, there will
be a "hash" zone in which the two signals fight with
each other. However, at night, considering the very high
level of interference on 1400 (there are approximately
300 stations on the frequency in the US and Canada, most
operating with 1 kW ND), the hash zone is probably
completely outside the interference-free contours.
>
> Could someone please explain the WLLH setup? I have been following this
> with great interest and it's really got me confused. Am I correct in
> thinking that there's a transmitter in both Lowell and Lawrence
> broadcasting on the same frequency?