"Bruce in Alaska" wrote in message
...
In article WN_Yf.1391$_u1.990@pd7tw2no, "surfnturf"
wrote:

While on the topic of antennas, what do you all think about the issue of
RF
exposure and the recomendation that omni directional antennas with a
gain of
under 9 dB be mounted 5 meters (15 ft) above deck level?

Even the 1 meter above head level given as minimum height for the base
of
the antenna seems to be ignored on many boats.

surfnturf



RF Radiation is NOT ever going to be a problem on ANY non-commercial
vessel. Period. None of the radiators that one can buy and install
ever even come close to maximum RF Radiations Power Densities considered
the Safe Levels. The same is true for most commercial Marine
installations. My only concern would be to make sure that any MF/HF
Antenna system be well insulated at any place where a person could come
in contact with it. GTO-15 certainly would do this job for wire
antennas, or a nonconductive insulating layer applied to any other
antenna section that is within reach of a humans. The worst that could
happen, should a person come in contact with the above, while
transmitting, is that they could get an RF Burn, that is going to smart
for a few days, but heck, an operator can get that, from a MF/HF Radio
that doesn't have an adiquate RF Ground, from the Mic Hangup Button.

Old Chief Lynn, will certainly testify to the above.....

Military Vessels are a completely different can of worms, and they ALL
have proceedures, and Operational Rules that are in place to protect
operators and others who work in proximitry to the Radiating Surfaces.

Bruce in alaska

My humble opinion is that the radiation from the antenna of a 25 watt
VHF transmitter probably doesn't do a person much good. However when
considers how long the transmitting continues, it is probably nothing to
worry about. (unless you have completely run out of things to worry about)
How long do you hold the mic button down on an average cruise, anyway?

Radiation from MF/HF transmitting antennas probably poses equally
little to fear. But as Bruce points out, exposed wires and terminals can
bite! And the smoke from RF burns on your nose, ears or fingers smells bad
too.

It would impress visitors to the radio room when the operator would
hold a fully lit 40 watt fluorescent tube in his hands, with no wires
attached.

A lead pencil to draw RF arcs was much safer, and was a good indication
that something coming out of the transmitter. And was a dandy tuning aid,
too. Just tune for longest arc.

Old Chief Lynn