[Lowfer] Still looking for a capacitance dissapation factor test

Mon, 17 Nov 2003 22:58:09 -0600

I would say yes you would see the drop across the cap as the A/C resistance
of the cap and the resistor would drop the rest of the voltage.

Mike>WE0H

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Lisa Cianciolo AKA Paul
Sent: Monday, November 17, 2003 10:59 AM
To: [email protected]
Subject: [Lowfer] Still looking for a capacitance dissapation factor test

Hello Folks,

Acces to email is kind of spotty here at work today. I am in the process of
changing computers.  Back to the good stuff.

In order to resonate my 5/8" Cu loop it took 488 PF.   The capacitor
consisted of a transmitting .0004 mica Bakelite block, soldered directly to
a 300 PF wide spaced  variable air capacitor.  This arrangement seems to
work ok if not a little difficult tune.

My LCR meter unfortunately is of the type that uses a 1 Khz signal for
testing.
So does anyone know of a test that I can perform at 1704Khz to measure the
loss in the cap?

I have made my own air variable from copper tubing using a TEFLON bushing at
each  end of the and sliding another tube down the middle.  The bushing let
the capacitor have of dielectric made primarily of air.

If I made a voltage divider with say a resistance and the cap in series,
wouldn't I be able to see the voltage drop across each component with a
scope?

Any help appreciated.

Thank you

PaulC
W1VLF

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