Curious about a posting at CBS58 ...

[Todd Wiedemann]

I was perusing www.cbs58.com (http://www.cbs58.com) and came across a post I will re-post here.

I'm curious regarding some of the technical aspects of broadcast frequencies and how they effect hospital equipment.

Kevin, could you please help from the medical side ??

PS - Check out 'Scheduled on-air date' http://www.milwaukeehdtv.org/ubb/wink.gif

Thanks:

*****
To: Administrator or Biomedical Engineer

From: WDJT-TV / Milwaukee, WI

Date: March 8, 2002

Notice of Commencement of Digital Television (DTV) Operation
THIS LETTER CONCERNS POTENTIAL INTERFERENCE TO TELEMETRY OPERATION. PLEASE ASSURE THAT THOSE WHO SUPERVISE CLINICAL OR BIOMEDICAL ENGINEERING AT YOUR FACILITY RECEIVE IT.

We are notifying you of the Station’s intention to begin DTV operations because your facility may use biomedical telemetry devices that operate on frequencies within the television broadcast band, and the proper operation of such devices may be negatively affected when the Station begins DTV service. This notice is provided to you with as much lead-time as possible as the Federal Communication Commission notified us of a grant to begin operations on March 7, 2002.

The rules of the Federal Communication Commission (codified at 47 CFR 15.242) have allowed certain biomedical telemetry devices to operate on unoccupied DTV channels on a secondary basis. This means that the medical facility or operator of such a device is responsible for resolving any interference problems that may arise once the Station commences digital television broadcast service or, alternatively, must cease operation of such affected devices.

The purpose of this notice is to provide you advance information so that you may resolve potential problems. However, you will want to discuss this with your technology supplier especially if you believe that biomedical devices used in your facility are likely to malfunction when the Station begins DTV operations. WDJT began limited tests of its DTV facilities on March 1, 2002. If you plan to replace your biomedical equipment, we urge that you purchase equipment designed to operate in the frequencies set aside for medical use.

The commencement date, DTV channel and frequency band for WDJT are listed on the attached page along with contact information for the broadcast executive in charge of DTV for the Station. Any modifications following this notification will be available on the WDJT website, www.cbs58.com. (http://www.cbs58.com.) This website address is included in the attached pages. If you desire more information or wish to report anticipated or actual interference problems, please contact the Station representative on the following page.

Respectfully,

Jim Hall

General Manager, WDJT-TV

The relevant details of our proposed DTV operations are as follows:

WDJT-TV Channel 58 CBS Network Weigel Broadcasting Co.

DTV Channel: 46

Scheduled On-Air Date: Monday, March 11, 2002 at 5p

Frequency Band: 662-668 MHz

Effective Radiated Power: 11.7kW

Antenna Location: N. Latitude: 43-06042

W. Longitude: 87-55-50

Antenna Height: 348 meters radiation center above ground

322 meters radiation center above average terrain

Contact Name & Title: Kevin Kukowski, Chief Engineer

WDJT-TV, 809 S. 60th St., Milwaukee, WI 53214

Telephone: (414) 777-5800

Fax: (414) 607-8105

Email address: kkukowski@cbs58.com

Website address: www.cbs58.com (http://www.cbs58.com)

[Tom Weeden]

Some biomedical devices are permitted to use frequencies inside vacant TV channels.

The problem first started back in 1998 when WFAA-DT Dallas/Fort Worth signed on their DTV transmitter on channel 9 and wiped out some heart monitors at Baylor Medical Center which were using frequencies within channel 9 (which was formerly unoccupied by any TV stations).

Now all DTV stations are required by FCC rules to notify all hospitals and medical facilities within their coverage area before they sign on to keep this from happening again.

See link at http://www.transmitter.com/curr1998/curr9803.html#CURR98-03-09
...and scroll down to the WFAA-DT story.



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--Tom Weeden
Amateur Radio WJ9H
Chief Engineer, WMTV
Madison, WI

[Kevin Arnold]

But look at the bright side. The nurses can sit and watch Leno in HD instead of those boring heart rhythms.
Its not uncommon for hospitals to have wireless heart monitors that are fairly old and on these frequencies. They tend to lose track of what they're using and this forces them to inventory their stock.

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Kevin Arnold
38" RCA widescreen w/a Winegard on a rotor.