NEW FACTS ABOUT EMP - Very Interesting!


The National Communications System (NCS), a governmental entity made up from
22 different Federal agencies, wants ham radio operators and their gear to
survive an EMP (Electro-Magnetic Pulse) generated "nuclear event."

NCS engineers have simulated the EMP phenomenon in the laboratory and have
subjected various pieces of current amateur radio gear to its effect.

The people at NCS came to some rather surprising conclusions.

In their report they say, "It was concluded that modern solid-state amateur
radio equipment was more survivable in an EMP transient environment than had
been previously anticipated."

What makes those sophisticated and delicate transistors and ICs so

The secret is in having two EMP surge protection devices. One is needed on
the end where the power comes into the radio and the other on the antenna
end where the RF signal goes out.

The NCS tested various commercially available suppression devices designed
for both lightning and EMP and, in a move surprising for any governmental
agency, issued a report telling which ones worked and which ones didn't.

Their findings and recommendations are outline in a 105-page publication
entitled "Electromagnetic Pulse/Transient Threat Testing of Protection
Devices for Amateur/Military Affiliate Radio System Equipment"--otherwise
known as NCS Technical Information Bulletin 85-10.

When considering EMP protection for transient voltage spikes coming in
through commercial power lines, the folks at NCS recommend the TII model 428
plug-in power line protector, an item which costs only $45. But for those a
little strapped for cash
(and what survivalist isn't), the report shows how you can make one yourself
for an estimated cost of only $11.

For EMP protection on the antenna side of a rig, NCS recommends the Fisher
series of spikeguard suppressors. They come in a variety of different
clamping voltages, depending on the characteristics of a specific station.

The bulletin provides a mathematical formula to determine which fisher model
is correct for your radio.

The Fisher devices cost $55, thus giving hams total effective EMP protection
for their radios with off-the-shelf items for only $100.

If your radio has a power output of 100 watts or less, a second coax
protector was recommended, the PolyPhaser products. They proved to be just
as effective as the fisher products but cost somewhat more--$82.95 each.
Because of their lower clamping
voltages, they are recommended only for lower wattage transmitters.

But again, for those handy with electronics, NCS shows you how to make a
simple home-made protection device for your antenna system for only $9.

It was interesting to note that two relatively inexpensive devices simply
did not work. The Archer (Radio Shack brand) AC line protector was NOT
recommended. Nor was the Alpha Delta brand "Transi Trap" coax protector,
commonly advertised in ham radio magazines.

Other interesting findings made by NCS engineers were that portable
generators, such as Honda types, were not likely to be adversely effected by
EMP at all. Neither were hand-held walkie-talkie type portable radios,
particularly those with short stubby "rubber duck" antennas.

The importance of a proper grounding system for amateur radio stations was
discussed in the report with specific recommendations for maximum