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Measuring C, HV Resistors, etc.
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From: Steve Young [SMTP:youngs-at-konnections-dot-com]
Sent: Monday, June 08, 1998 11:55 PM
To: Tesla List
Subject: Re: Measuring C, HV Resistors, etc.
> From: D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
> Sent: Monday, June 08, 1998 11:30 AM
> To: Tesla List
> Subject: Re: Measuring C, HV Resistors, etc.
>
> to: Steve
>
> Happen to have a tel number and address for Tech America??
>
Yup: Catalog order is 1-800-303-4450 ext 2105.
Parts order is 1-800-877-0072.
Fax parts order is 1-800-813-0087.
They are a mail order outfit, with address of P. O. Box 1981
Fort Worth, TX 76101-1981
But they have walk-in stores in Denver and Atlanta.
Hams might know the VP of the company - Bob Miller, K2RM.
--Steve
> DR.RESONANCE-at-next-wave-dot-net
>
>
> ----------
> > From: Tesla List <tesla-at-pupman-dot-com>
> > To: 'Tesla List' <tesla-at-pupman-dot-com>
> > Subject: Measuring C, HV Resistors, etc.
> > Date: Sunday, June 07, 1998 10:21 PM
> >
> >
> > ----------
> > From: Steve Young [SMTP:youngs-at-konnections-dot-com]
> > Sent: Saturday, June 06, 1998 11:42 PM
> > To: Tesla List
> > Subject: Measuring C, HV Resistors, etc.
> >
> > To all,
> >
> > 1) Every now and then, someone posts their need for inexpensive way to
> > measure C. A great source for all sorts of parts is Tech America.
Their
> > catalog is available at Radio Shack, or you can get one via their
website
> > at www.techam-dot-com. They sell a kit (part number 990-0043) for $13
which
> > lets one use a DVM to measure 2pf to 2 mf.
> >
> > 2) Occasionally, coilers indicate a need for HV resistors. If you
don't
> > mind a lot of soldering, you can make your own very cheaply. Tech
> America
> > sells resistors for 100 for a dollar. Use 1/2 watt resistors which
have
> a
> > rating of 350 volts. For example, suppose you have a 20,000 ohms per
> volt
> > meter which can measure 5 KV, but you want to measure up to 15 KV.
Just
> > add 67 3 meg 1/2 watt resistors (200 meg) in series with the test lead
> and
> > presto, you have a 15 KV meter. Cost is 67 cents. The resistor string
> > will be good for at least 23 KV and can dissapate 20+ watts. Be sure
to
> > arrange the ends of the resistor string so the HV doesn't flash over
> > possibly resulting in a fried meter. It would help to put the string
in
> > oil to reduce corona and improve heat dissapation.
> >
> > If you don't care about the exact value of the HV resistor, then
another
> > easy solution is to use plastic tubing filled with tap water. Push
wires
> > through plugs in the ends of the tube. Such resistors work great in a
> Marx
> > generator, for example. Just be sure the wires in the tube are at
least
> a
> > few inches apart so they don't arc over and explode! Even though the
> > resistance is not very predictable, you can still make an accurate
> voltage
> > divider. For example, a hundred foot hose with a electrode pushed
> through
> > at the 1 foot spot would make a 100:1 voltage divider which could
handle
> > many KV.
> >
> > 3) Tech America has just started carrying a line of Amidon toroidal
> cores.
> > Biggest ones are 2 inches O. D.
> >
> > --Steve
> >
>
>