Thanks for the safety tips. I am sure the ALS-1300 at 50V and a peak of 50
amps could melt a screwdriver or a gold ring. Would wearing latex exam
gloves offer any extra protection when working on a radio?
Tom AG8K
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
To: <tentec@contesting.com>
Cc: <collins@mailman.qth.net>
Sent: Thursday, February 18, 2010 5:25 PM
Subject: Re: [TenTec] Electric safety
> On Thu, 2010-02-18 at 16:05 -0600, Pumbaa wrote:
>> That is one thing (HV) I did consider when I decided to buy the Ameritron
>> ALS-1300 Solid State Amplifier. The other is the lack of used Centurion
>> amps for sale.
>>
>> Tom AG8K
>>
> While the mark left by high voltage may be small, a low voltage supply
> can cause amputations, especially a lead acid battery. 12 volts at a 100
> amps through a wedding ring can amputate that finger cleanly. That much
> current through a metal watch band can do a lot of damage too.
>
> For that matter when shock is involved, the "ordinary" 120 volt circuit
> is more deadly than high voltage in most situations. That's because high
> currents stop the heart, then when you fall down the bump is a pretty
> good heart starter. But 120 volt shocks often put the heart into
> fibrillation, and in that operating mode the heart's reflexes are
> satisfied though it pumps no blood. 4 or 5 minutes and you're brain
> dead. A few more and your dead all over. You can only be brought of
> fibrillation with a defibrillator to give a massive short shock to stop
> the heart and let it bounce into a normal rhythm again.
>
> True, the burns from a 7 KV power line are bad but I had several clients
> who survived those and several families of those shocked by tools
> supplied with 120 volts that didn't survive. And I had to explain why in
> my consulting business over the past several decades.
>
> High current and any voltage demand some attention and care. Even if the
> shock isn't severe enough to cause major injury or heart problems the
> speed with which the shock can cause your arm muscles to contract and
> you to extract your hand from the radio can cause the back of your hand
> to loose much skin as it hits stuff on the way out of the radio.
>
> Good safety rules require no watches or rings when working with live
> electricity at any voltage. Good safety rules require you to not work on
> high voltage apparatus with the power on, and after the power is off AND
> thoroughly disconnected in a way that NO ONE can apply power (like pull
> the plug and put it IN your pocket) short the power supply with a metal
> rod on an insulating handle, and park it there until you are finished
> with the work. E.g. short it and keep it shorted. And there's the old
> rule, one hand in pocket, one hand in circuit. That minimizes the
> current paths through the heart, but you can still jump fast and high
> without control and the bounces can get you into deep trouble, like
> landing ten feet from the foot of the ladder you were on.
>
> 73, Jerry, K0CQ
>
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