My Coast Guard notice to Mariners is from 2006.



"Jeff" wrote in message
. ..
You're becoming the master of obsolete info - the report you cite turned
out to be erroneous. Shakespeare ended up recalling 400 units that were
built during one month for each style.
http://www.shakespeare-marine.com/an...tvantennas.htm

Here's the updated safety alert that specifies only one date code for each
of the Shakespeare units:
http://www.uscg.mil/hq/g-m/moa/docs/11-02.htm


Gilligan wrote:
"Jeff" wrote in message
. ..
Gilligan wrote:
Shakespeare Ampified Omni Marine Antenna recalled:

http://www.zurichmarinespecialty.com...nerboating.pdf

Read about it on page 7. Apparently it wipes out GPS units for nearly
1/2 mile.

There was no general recall, and the problem only affect several hundred
units, none of them were omnidirectional.

Marine Safety, Security and Environmental Protection
November 15, 2002
Washington, DC


It has come to the attention of the U.S. Coast Guard and Federal
Communications Commission that certain consumer electronics-grade active
VHF/UHF marine television antennas are causing operational degradation in
the performance of Global Positioning System (GPS) receivers. This
interference may be realized as a display of inaccurate position
information or a complete loss of GPS receiver acquisition and tracking
ability.

The interference is not limited to the GPS equipment onboard the vessel
with the installed active marine television antennae. There have been
reports of interference occurring on other vessels and installations
operating up to 2000 feet away from vessels using such antennas.

In one particular case, the interference caused the position of the
vessel as displayed on the electronic chart to move erratically and
dramatically often across large expanses of land. As can be expected,
various data displays indicated erroneous information such as excessive
speeds. In these instances the problem would occasionally correct itself
while at other times required resetting the system. To the vessel's crew
these annoyances were frustrating and caused concerns that perhaps less
obvious inaccuracies were occurring. Ultimately this affected their
confidence in the performance of the GPS and Electronic Chart Display and
Information System.

If you are experiencing recurring outages or degradation of your GPS
receiver operation you should perform an on-off test of your TV antenna.
If turning off the power to the antenna results in improvement in the GPS
receiver performance, the antenna may be the source of interference in
the GPS band. In that case, you should contact the manufacturer of the
antenna and identify the symptoms.

If the test is not positive and the GPS interference persists, contact
the watchstander at the Coast Guard Navigation Information Service at
/ 703.313.5900.

Antennae models identified during investigations of GPS interference.

TDP (Tandy Distribution Products) Electronics - MINI STATE Electronic
Amplified UHF/VHF TV Antenna - Models 5MS740, 5MS750, 5MS921

Radio Shack Corporation - Long Range Amplified Omni Directional TV
Antenna - Model 15-1624

Shakespeare Corporation - SeaWatch - Models 2030, 2050

This material is provided for informational purpose only and does not
relieve any existing domestic or international safety, operational or
material requirement.

RELEASED BY - Office of Investigations and Analysis, USCG Headquarters.
Questions or comments related to this information or its delivery may be
addressed to Mr. Ken Olsen at 202.267.1417 or .



Also at:
http://www.nga.mil/MSISiteContent/St...tM_01-2006.pdf

Shakespeare 2030:

http://www.shakespeare-marine.com/an.../tv/2030-g.htm

Described and marketed by manufacturer as omnidirectional. It's on the
recall list.