To Find An Unknown Capacitor Value - Heathkit HD-1250 Manual

Page 50
TO
FIND
AN UNKNOWN
CAPACITOR VALUE
Refer to Figure 3-3
for the following
steps.
1
.
Connect
the
unknown
capacitance
across
a
phono
socket
as
shown.
2.
Plug
any
of the pickup
coils,
except the brown
coil,
from
the dip meter
set
into the
phono
socket.
3.
Adjust the Dip Meter
for use
in
the injection
mode
of operation.
NOTE:
By
trial
and
error,
you
may
need to plug
any
of the remaining
coils
into
the
coil
socket
on
the
Dip Meter to determine
the resonant frequency
of
the
"test circuit."
Record
the
frequency
{f
),
in
MHz, from
the
dial.
4.
Refer to Table
A
and
find the color of the
coil
which you
used
in
the
phono
socket.
Record the value of the inductor
(L) in
henries.
5.
Substitute the recorded
quantities
in
the
formula below
to determine the
value of the
unknown
capacitor
in
farads:
47r
2
f
2
L 39.48
xf
2
xL
Note:
1
MHz = 10
6
Hertz
1
nF
=
10"
6
farads
1
pF = 10-'
2
farads
f
=
dial
reading
(MHz)
L
= Inductance
(in
Henries)
COIL
COLOR
INDUCTANCE