Re: WLLH-AM Lawrence transmitter off-air

[dan.strassberg@att.net]

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?