Jim Weir or other qualified persons: a tangent on the 2 radio 1 antennathread

Brian Whatcott wrote in message . ..
On Mon, 14 Jun 2004 15:17:48 GMT, Dave S
wrote:
//
My question is, given the limited "resistance" of some of the radio
components (and the ability to tolerate less than a watt input if I
paraphrased it correctly) I am wondering just how much energy the radio
system is being exposed to flying by the transmitting elements a mile
away laterally, and how prudent that is for the longevity of the
components. Lets use 50,000 watts if that is appropriate for the example.

Dave

You are not the only one who has experienced breakthrough
near a big transmitter tower. Here's a rough, rough estimate of
intercepted power.
If 50 kw were distributed through a spherical surface of 1 mile in
radius, what would the power intercepted by one square yard?
(arbitrary cross-section value for a 1/4 wave whip...)

power times Antenna cross-section / Extended surface area
[4/3 pi r squared] = 4 milliwatts

Into 50 ohms, that would amount to v^2/50 = 0.004
v^2 = 0.2 v^2 so V = 0.4 volts very roughly....

Brian W


Could something similar happen if I get painted by a NEXRAD weather
radar? There's one about a quarter mile away from our airport, and
every now and then (seemingly random but it only happens in the
pattern) a get a quick "fweem" over the intercom... I've noticed it in
Cessnas once or twice, and the RV. Some days I don't get it; other
days I'll hear it three or four times.