[TowerTalk] RF Voltage at AM Tower Base

[donmar1234 at aol.com]

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Message: 1
Date: Sun, 1 Feb 2009 21:31:58 -0800
From: Patrick Barthelow <apolloeme at live.com>
Subject: [TowerTalk] RF RadHaz safety
To: <towertalk at contesting.com>
Message-ID: <BLU123-W23C5C31E44FDEEE0797F78DFC50 at 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 at 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