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Bob July 13th 05 05:36 AM

High Voltage Techniques
 
Since Curious George asked a basic question, I will ask one also. For those
of us that are used to working with low voltage equipment, what is a good
book for learning to work with the high voltages of tubes?



K7ITM July 13th 05 05:46 PM

Try any of the older Radio Amateur's Handbooks for a start, for
practical stuff. Are you looking for how to work safely with high
voltages, or for practical circuits, or for theory? Are you interested
in RF power amplifiers, or something else?

Cheers,
Tom


[email protected] July 13th 05 06:34 PM

From: "Bob" on Tues 12 Jul 2005 23:36

Since Curious George asked a basic question, I will ask one also. For those
of us that are used to working with low voltage equipment, what is a good
book for learning to work with the high voltages of tubes?


The "best book" is simply COMMON SENSE. Use your eyes and brain.

If the voltage and current through your body in the path of the
heart is above 30 Volts and greater than 30 mA, you have the
approximate threashold of cardiac fibrillation...where the
heart loses its normal oscillation and begins to "flutter"
and not pump blood. Potentially fatal if this "30-30" rule
is exceeded.

DON'T GRAB LIVE HIGH VOLTAGES WITH BOTH HANDS. [guess where
the heart is located in this body "circuit"?]

A common mistake of the above is leaning on a conductive surface
touching it somehow when probing with the other hand...the
"circuit" has been completed even though it may not enter
awareness.

Be AWARE of the maximum voltage limitations on all your measuring
equipment. If a manufacturer says "input voltage 500 V max"
that IS what they mean...there's a "fudge factor" in that rating
but try NOT to use it. Do not destruct expensive test machines
or the circuit you're testing.

THINK about what you are doing around high voltage. Thinking
will enable you to continue living to think some more about
other things.

RESPECT high voltage. It ain't no kiddie toy to fool with.



[a high voltage survivor in the biz since 1948]


Bill Janssen July 14th 05 01:07 AM

wrote:

From: "Bob" on Tues 12 Jul 2005 23:36



Since Curious George asked a basic question, I will ask one also. For those
of us that are used to working with low voltage equipment, what is a good
book for learning to work with the high voltages of tubes?





An RCA tube manual and the warnings as stated below.

Bill K7NOM

The "best book" is simply COMMON SENSE. Use your eyes and brain.

If the voltage and current through your body in the path of the
heart is above 30 Volts and greater than 30 mA, you have the
approximate threashold of cardiac fibrillation...where the
heart loses its normal oscillation and begins to "flutter"
and not pump blood. Potentially fatal if this "30-30" rule
is exceeded.

DON'T GRAB LIVE HIGH VOLTAGES WITH BOTH HANDS. [guess where
the heart is located in this body "circuit"?]

A common mistake of the above is leaning on a conductive surface
touching it somehow when probing with the other hand...the
"circuit" has been completed even though it may not enter
awareness.

Be AWARE of the maximum voltage limitations on all your measuring
equipment. If a manufacturer says "input voltage 500 V max"
that IS what they mean...there's a "fudge factor" in that rating
but try NOT to use it. Do not destruct expensive test machines
or the circuit you're testing.

THINK about what you are doing around high voltage. Thinking
will enable you to continue living to think some more about
other things.

RESPECT high voltage. It ain't no kiddie toy to fool with.



[a high voltage survivor in the biz since 1948]




Ed July 16th 05 08:31 AM

Thanks all. Tom, I've been in electronics thirty years or so, but always
solid state.Now I'm going backwards to boatanchors. I know most of the old
sayings such as "keep one hand in your pocket" etc., but I'm more interested
in practical considerations of draining capacitors, proper wiring
techniques, and so forth. I know that even unplugged tube devices can jump
out and get you, and I'd like to avoid this...especially in high power RF
amplifiers. I've got Bill Orr's handbook, years of old magazines from the
50's, and ARRL handbooks; great circuits but little in technique. It's like
school, great on theory but troubleshooting is only taught in the doing.
73, Bob.
"K7ITM" wrote in message
ups.com...
Try any of the older Radio Amateur's Handbooks for a start, for
practical stuff. Are you looking for how to work safely with high
voltages, or for practical circuits, or for theory? Are you interested
in RF power amplifiers, or something else?

Cheers,
Tom




Gary S. July 16th 05 03:34 PM

On Sat, 16 Jul 2005 02:31:49 -0500, "Ed" none@this-time wrote:

Thanks all. Tom, I've been in electronics thirty years or so, but always
solid state.Now I'm going backwards to boatanchors. I know most of the old
sayings such as "keep one hand in your pocket" etc., but I'm more interested
in practical considerations of draining capacitors, proper wiring
techniques, and so forth. I know that even unplugged tube devices can jump
out and get you, and I'd like to avoid this...especially in high power RF
amplifiers. I've got Bill Orr's handbook, years of old magazines from the


One thing to consider is to make and use a "chicken stick". Don't
touch anything electrical until you have touched it with the chicken
stick.

This is essentially a ground wire (to a solid ground) with a well
insulated handle. To avoid component damage, add a low ohmage, high
wattage resistor in series.

A chicken stick is routinely used in commercial HV equipment, and
power company linemen have a portable equivalent.

Better to be a live chicken than flambeed.

Ref:
http://lists.contesting.com/archives/html/Amps/2004-08/msg00245.html
http://www.k0gkd.com/sb220.html

Happy trails,
Gary (net.yogi.bear)
--
At the 51st percentile of ursine intelligence

Gary D. Schwartz, Needham, MA, USA
Please reply to: garyDOTschwartzATpoboxDOTcom


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