What will the Boston television frequencies be after February

[Scott Fybush]

Larry Weil wrote:
> At 5:37 AM -0800 12/6/08, Maureen Carney wrote:
>>
>> I seem to remember that when a station in Dallas experimented a 
>> digital signal on a low V (IIRC channel 4) it interfered with medical 
>> equipment at a nearby hospital.
> 
> Why would a digital signal cause interference if an analog signal on the 
> same frequency wont?  Or was that not considered in this particular test?
> 

The case that Maureen refers to actually had nothing to do with low-band 
V. It was one of the very first DTV signals on the air, WFAA-DT in 
Dallas, circa 1998.

WFAA's analog is on channel 8. A hospital in Dallas was using channel 9, 
then vacant in the Dallas area, for low-powered medical telemetry 
(heart-rate monitors and such) - and when WFAA-DT fired up for the first 
time on channel 9, its signal blew the telemetry signals out of the water.

Chalk it up to "learning experience" - the hospital equipment was 
licensed, as I recall, as a secondary user on channel 9 (that being one 
of the few secondary uses that can be licensed on vacant TV channels), 
and somehow nobody realized that the hospital should probably have been 
warned in advance that it would need to change frequencies on its equipment.

My recollection is that WFAA-DT shut down for a bit so the hospital 
could get things moved (it's not like anyone had receivers at that 
point, anyway), and I guess there must be a better notification scheme 
in place now, because I haven't heard of any problems like this in the 
decade since WFAA had its issues.

s