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Message: 1
Date: Sun, 1 Feb 2009 21:31:58 -0800
From: Patrick Barthelow <apolloeme@live.com>
Subject: [TowerTalk] RF RadHaz safety
To: <towertalk@contesting.com>
Message-ID: <BLU123-W23C5C31E44FDEEE0797F78DFC50@phx.gbl>
Content-Type: text/plain; charset="Windows-1252"
Relative to the pictures of KGO AM 810 TX antennas, referenced in an
earlier post, Some (all) of us who visited KGO, very much respected
the danger of touching the bare copper feed conductors going
to the base of each tower that were in easy hand reach.
Especially while squishing through the saturated saltwater
marshy mush of the ground at the 1/4 wave tower bases. A discussion
ensued among the hams, of whether any nasties would happen if you had to
do maintenance on the tower, while hot @ 50KW if you could safely jump
the ground to the insulated (hot) base of the tower. Or even if not safe in
the OSHA/FCC RAD HAZ sense, would you would likely receive an
RF burn of any kind by hopping onto the tower never connecting to the
ground and the tower at the same time?
Some say, you would feel nothing,
others thought there could be significant charging current at 50 KW that
you probably would get a painful, possibly dangerous ZAP, on contact,
even if not touching ground...
Picture collection of KGO:
http://www.dxhound.com/KGO%20visit%202005/jj_test_KGO.htm xxxx
Best Regards, 73,
Pat Barthelow apolloeme@live.com
Executive Producer
"Echoes of Apollo"
A celebration of the Apollo 11 Moon Landing 40th Anniversary,
and exhibit of world wide Moon Bounce, EME Communications
"On Wings of Eagles":
http://www.parkes.atnf.csiro.au/news_events/apollo11/
http://www.jamesburgdish.org
Regarding the first part of your question, a fence must be maintained
around the base of a series-fed AM radio tower to prevent a shock hazard to the
public
per FCC Rule 47 C.F.R. 73.49. When tower maintenance is required, the
station(s) involved
are required to lower their power to a safe RFR (radiofrequency radiation)level
per 47 C.F.R. 1.1310. You don't have to feel the burn to be in danger!
73,
Don
KW7R
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