On 1/25/2014 2:42 AM, Jeff Liebermann wrote:
On Fri, 24 Jan 2014 19:44:38 -0800 (PST), W5DXP
wrote:
On Friday, January 24, 2014 5:16:15 PM UTC-6, Jeff Liebermann wrote:
Mythbusters did a test of urinating on an electrified 3rd rail.
It didn't work.
I got a severe static electricity shock in Odessa, TX one time
while urinating into a hotel john. I saw the arc between my stream
and the water in the john. The hotel had wool carpets and the
humidity was very low.
Ouch. I feel your pain. Wikipedia claims 3 million volts/meter (or
about 75,000 volts/inch) which seems a bit high:
http://en.wikipedia.org/wiki/Dielectric_strength#Breakdown_field_strength
I've always used 10,000 volts/inch but I don't recall the conditions
for which that's accurate. In any case, you had quite a (static) high
voltage buildup, which could jump the broken parts of the urine flow.
1000 watts into a ground mounted HF vertical? Is that a good idea? It
might be too close to the operator to be within accepted RF exposure
(MPE) limits. Checking:
http://transition.fcc.gov/Bureaus/Engineering_Technology/Documents/bulletins/oet65/oet65b.pdf
See table 4a on Pg 23. For 1000 watts the minimum distances for a
typical 0dBi gain antenna is:
Band Controlled Uncontrolled (meters)
160m 0.5 0.7
80m 0.6 1.3
40m 1.1 2.5
20m 2.2 4.8
15m 3.2 7.2
10m 4.5 10.
So, if he's operating on 20 meters, a ground mounted antenna with no
gain and 1000 watts can't be any closer than about 14 ft from the
operator. Maybe with a big yard and if you don't care about cooking
the dog or the neighbors.
In order to put the voltage node of the vertical near where the dogs
urine stream can reach, it would need to be fairly close to the
ground. That leaves very little room for the ground radials, any
possible control box, or a balun. Seem an odd vertical antenna with
the loading coil at ground level. Maybe for 160 meters or a mono band
antenna.
Who said how close it was to the operator? And who said there was a
control box or balun involved? Neither are required for a properly
tuned vertical.
And radials on a ground mounted vertical go (preferably) UNDER the ground.
When I first started out in ham radio, I used a Hy-Gain 18AVQ vertical -
80-10, with the instructions saying to mount one foot (that's twelve
inches for the trolls) above ground with an SO-239 to connect to the
coax. Quite within range of a large dog.
But once again you show your ignorance of facts. OTOH, your lack of
knowledge really is entertaining. More so than most trolls, anyway.
--
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Jerry, AI0K
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