Conelrad in Boston area

[Kevin Vahey]

Back in the 50's and early 60's national alerts were to be transmitted
by Conelrad at 640 and 1240 on the dial.

I recall one afternoon in the early 60's that all Boston ( and perhaps
it was nationwide ) stations signed off for a Conelrad test and
listeners were asked to go to 640 or 1240 for instructions.

Where were the Conelrad transmitters liocated for Eastern Mass?