Re: [Elecraft] Lighting

[Ed Cole]

Another anecdote:

Summer of 1981 I was working for the BLM Alaska Wildfire Center in 
Fairbanks as a radio tech.  That summer a Class-A fire started near the 
town of Livengood and only three miles away from the Alaska Pipeline 
that brings crude oil from the north shore down to Valdez.  There was 
great concern that the fire would reach the pipeline so large response 
was activated.  I was assigned as the Radio Officer for this.


The main base camp was set up on a 2400-foot high ridge that overlooked 
the fire.  We had a tent dispatch center consisting of two vertical VHF 
antennas mounted on two 30-foot fiberglass "Hot Sticks" (so name as the 
telescoped from 8-foot and primarily used by power line workers for high 
tension lines).  From this contact was made over 75-miles to the BLM Base.


A wind storm generated considerable static electricity such that the 
HT's lying on the ground would draw a six inch arc if one were to try 
picking up the radio.  Initially being told by one of the dispatchers 
that the "radio bit her", I scoffed that a 6v radio could do that and 
promptly demonstrated my "intelligence" by getting shocked when I tried 
to pick one HT up.  Took me a bit to work out what was happening.  There 
was a pause in dispatch for almost an hour.


73, Ed - KL7UW
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Re: [Elecraft] Lighting

[David Gilbert]

The current can be an issue, though if you have anything metallic in 
your hand.  Solid state linear power supplies are basically arc welders.


73,
Dave  AB7E


On 8/24/2022 4:52 PM, jerry wrote:



   One of the most endearing things about my solid state linear 
projects is that there's nothing in there that will kill me.  Just 53V.


 - Jerry, KF6VB



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Re: [Elecraft] Lighting

[jerry]

On 2022-08-24 14:23, David Gilbert wrote:

Several years ago before my house was fully completed, I had my coax
lines disconnected but just lying on the concrete floor of the room I
had my ham gear in.  I usually had those lines terminated in a short,
but one day as a storm was approaching (it was still at least five
miles away) I noticed that the line from the 80m dipole didn't have
the shorted PL-259 on it.  I bent down with one hand on the concrete
floor and reached for the insulated casing on the coax with the other
hand.  My free hand swept by the end of the coax, though, and I drew a
very bright, very thick, and very blue 2 inch long arc to my hand ...
which of course traveled through my body to the other hand that was on
the floor.  My biceps were sore for three days afterward.


*** Ouch.  I actually have a high-ohms resistor that I plan to put at 
the

base of my vertical, just to drain off static.

   Once upon a time, I was working on a homebrew linear with 4 811A's.  
It
was oscillating and making noise during receive.  I was spudging at the 
plate
wires trying to get it to quiet down whenZAP!  I swear I didn't 
touch anything,
it reached out and touched ME.  Knocked me across the room, paralyzed 
both my arms.


   One of the most endearing things about my solid state linear projects 
is that there's nothing in there that will kill me.  Just 53V.


 - Jerry, KF6VB

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Re: [Elecraft] Lighting

[Fred Jensen]

While we're on the subject of huge amounts of static electricity, I've 
posted this before but it is important [see text]:  Precipitation static 
... rain, snow, and even dust ... can kill your radio, and it will do it 
with no rumble, flashes, sparks, and crashes.  On the panadapter, it 
will look like very low grass on the baseline.  In the cans, it may 
sound like very faint "frying" or may not sound at all.  Each flake, 
drop, or dust particle carries a minuscule charge which it deposits on 
the antenna.  However, there are gazillions of them.  Most front ends 
these days have an FET as the first stage, and the gate acts like a tiny 
capacitor, charged incrementally by each little minuscule charge coming 
down the coax. Eventually, if the precip lasts long enough, the gate 
will charge to the failure point.  You won't see or hear it coming but 
you can discern this when you suddenly don't hear anything.


Some current transceivers have a bleed across the antenna jack [100K-ish 
resistor or maybe an RF choke].  I "believe" Elecraft rigs do, but I've 
never checked.  Years ago, at the dawn of the transistor age, I learned 
to wire a PL259 with a 100K 1/2 W resistor shorting it, put a coax Tee 
on the antenna jack, connect the antenna to one arm, and put the PL259 
on the other.


Back around 2010 or so, four of us were activating Alpine County CA 
during the CQP.  We were at about 8,500 ft AMSL, and it began to snow 
[of course, with wind too].  Barely perceptible grass on the 
ICOM panadapter.  Suddenly, it got very quiet.  So we replaced 
it with the spare, and it met the same fate.


73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

PS The combined longevity of the 4 of us in ham radio was something 
around 200 years.  You'd have thought one of us would have remembered.


Gene Robinson wrote on 8/24/2022 1:54 PM:

Working at Collins in the 60’s we had a lab with no windows but we did have 18 
foot vertical antennas on the roof.
We would have NE2 neon bulbs connected to the RF coax feed lines and when 
thunderstorms were within 5 miles they would start to flash.
We all then went out to the parking lot and rolled up our windows.
The rain and lightning would arrive about 10 to 15 minutes latter.
The break down and flash voltage for a NE2 is 90 volts! Keep those antennas 
disconnected when not in use.
Gene N5LDX

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Re: [Elecraft] Lighting

[David Gilbert]

Several years ago before my house was fully completed, I had my coax 
lines disconnected but just lying on the concrete floor of the room I 
had my ham gear in.  I usually had those lines terminated in a short, 
but one day as a storm was approaching (it was still at least five miles 
away) I noticed that the line from the 80m dipole didn't have the 
shorted PL-259 on it.  I bent down with one hand on the concrete floor 
and reached for the insulated casing on the coax with the other hand.  
My free hand swept by the end of the coax, though, and I drew a very 
bright, very thick, and very blue 2 inch long arc to my hand ... which 
of course traveled through my body to the other hand that was on the 
floor.  My biceps were sore for three days afterward.


The breakdown voltage of air with 40% humidity (roughly what we have 
here in southern Arizona during the monsoons) is about 8kv/cm.  Of 
course that is also a function of the sharpness of electrodes, but still 
... I got zapped with a LOT of energy especially considering the 
thickness of the arc.  Apparently, though, it was too much to represent 
a lethal shock to my heart (which is more like milliamps) and too little 
to fry my body.


To be clear, that energy wasn't the result of a strike.  It was simply 
static buildup between the legs of the 80m dipole.  I short everything 
now when it isn't in use.


73,
Dave   AB7E



On 8/24/2022 1:54 PM, Gene Robinson wrote:

Working at Collins in the 60’s we had a lab with no windows but we did have 18 
foot vertical antennas on the roof.
We would have NE2 neon bulbs connected to the RF coax feed lines and when 
thunderstorms were within 5 miles they would start to flash.
We all then went out to the parking lot and rolled up our windows.
The rain and lightning would arrive about 10 to 15 minutes latter.
The break down and flash voltage for a NE2 is 90 volts! Keep those antennas 
disconnected when not in use.
Gene N5LDX

Sent from my iPhone
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[Elecraft] Lighting

[Gene Robinson]

Working at Collins in the 60’s we had a lab with no windows but we did have 18 
foot vertical antennas on the roof. 
We would have NE2 neon bulbs connected to the RF coax feed lines and when 
thunderstorms were within 5 miles they would start to flash.
We all then went out to the parking lot and rolled up our windows.
The rain and lightning would arrive about 10 to 15 minutes latter.
The break down and flash voltage for a NE2 is 90 volts! Keep those antennas 
disconnected when not in use.
Gene N5LDX

Sent from my iPhone
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Re: [Elecraft] Lighting Protection

[Doug Hensley]

Not quite on the topic but FWIW, I had Delta Products Surge units installed at 
the A/C line coming in to my shop.  Both are grounded and then tied between the 
hot & neutral lines.  Fairly inexpensive and somewhat of a "whole house" surge 
arrestor & protector.  They are made by a very responsive and helpful company:




http://www.deltala.com/


For less than $100 their two units provide some basic 24 x 7 protection.  Then 
you can fine tune from there.


Cheers,


Doug W5JV







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