RF Exposure Issues

[W8JITom at aol.com]

In a message dated 96-08-08 18:37:27 EDT, you write:

>	2. How can we accurately determine the duty cycle?  I saw Brian's
SNIP
>	   what is the time length of a space versus a 'dit' or 'dah'.

A dot is typically equal to the space between each dot and dash, and a dash
is typically three dots long. Typical uninterrupted CW text has an average
power less than 40% of the locked down carrier power (not including any
listening time).

The actual amount varies with the operator's sending habits, the CW weight,
what is being sent, and the rise and fall times of the envelope. 

>	   locations, and on page 24 I see that station C had a very high
>	   reading near a section of feedline (nearly 3 times as high as
>	   those taken in the immediate vincinity of the xcvr).  Now the
SNIP
> Offhand, this seems to indicate a 
>	   problem with the coax.  Is it reasonable to assume that this 
>	   was perhaps RG-8 or some other type with a shield ratio less
>	   than that of RG-213?

Shield "ratio" usually has little or no effect on coaxial cable radiation in
amateur installations. Most often the dominate problem is unequal currents on
the center conductor and shield caused by improper feedline routing or
termination. Changing the cable or even using double shielded cable, if the
cable is not defective or very poorly constructed, would be of no benefit.

Even a base fed vertical can require a choke balun(s) to suppress coaxial
feedline radiation.

73 Tom

>From n6ig at netcom.com (Jim Pratt)  Thu Aug  8 23:57:46 1996
From: n6ig at netcom.com (Jim Pratt) (Jim Pratt)
Date: Thu, 8 Aug 1996 15:57:46 -0700 (PDT)
Subject: VE3BMV RF radiotiontorial
Message-ID: <Pine.3.89.9608081514.A21131-0100000 at netcom14>

Gee...it's a good thing AOL stayed up long enough today for Yuri to type 
his message...

                                             n6ig at netcom.com


>From bills at halsey.com (Bill Sattler)  Fri Aug  9 00:50:00 1996
From: bills at halsey.com (Bill Sattler) (Bill Sattler)
Date: Thu, 8 Aug 96 16:50 PDT
Subject: Regulations
Message-ID: <m0uoeqF-002qM8C at halsey.com>

	I've been following the recent discussion concerning the possibility of new
regulations, and the castigation of old regulations with some interest.
Much of the discussion seems to be critical of "them", the evil city
governments and planning commissions who enact regulations inhospitable to hams.
	I'd just like to make the comment that most smaller towns are DESPERATE for
citizen involvement, and here's your chance to make a real difference.  I
know that big cities are a different matter, but in smaller towns pay
attention to the notices of vacancies on planning commissions and city
councils and go for it.  Five years ago I joined the local planning
commission, and am now President of the commission.  Do you think this town
is going to enact any rules about towers or RF levels???  In fact, our town
has a 35' height limit on structures, EXCEPT	radio towers and antennas, on
which there is NO height limit. :)
	Yes, it takes time, but not that much.  You'll get to know many of your
neighbors, and have a chance to make a difference in your community, and as
a side benefit, be able to keep an eye on thing that might affect your
CONTEST :) station.
	Don't get caught up in the "us against them" mentality, be proactive and
involved in the decisions that might affect you.
	Thanks for the bandwidth.
73
Bill Sattler
N0XX/7
bills at halsey.com