Heathkit TT-1 - Page 12

5. Leaving the SET LINE control set as is,
vary the FILAMENT switch through the po-
Sitions stated and again observe the meter
reading, This new reading should not vary
more than the value of ''V Reg" as stated in
the REMARKS column,
CAUTION: The following is a list of "DON'TS"
to be observed during the testing of voltage reg-
ulator tubes,
1, DO NOT insert the tube in the socket until
ha aod awa e ta
all controls to
set,
2. DO NOT make a leakage test,
3, DO NOT change any of the SELECTORS
while the tube is in the socket.
4, DO NOT rotate the SET LINE control after
the tube has fired and the final adjustment
has been made,
Failure
to
heed
the
above
comments
may
result
in
a
test
that
is
meaningless,
LOW-POWER THYRATRON TUBES
1, Follow Steps 1 through 4 of the general
instructions,
NOTE: The SIGNAL switch may be disregarded
when testing thyratron tubes and may therefore
be in any position,
2. tate BIAS control to 45 and insert the tube
into the proper socket,
3. Depress AMPL-RECT-DIODE switch to
Ve arUpe
RECT-DIODE position,
4, Slowly rotate the BIAS control toward zero,
carefully observing the meter, Note the
value of BIAS setting at which the meter
suddenly deflects up-scale, This is atest of
the tube's control grid characteristic; the
value of BIAS setting should fall between the
limits given in the REMARKS column, For
example, a tube having ''Fire 10-0 bias" in
the REMARKS column should fire at a bias
Setting between 10 and 0,
5.
With
the
AMPL-RECT-DIODE
switch
inthe
RECT-DIODE
position,
the
meter
pointer
must
fall
in
the
RECTIFIERS
OK
portion
of
the
scale
to
be
considered
good,
EYE TUBES
1. Follow Steps 1 through 7 of the general
instructions,
NOTE:
The
SIGNAL
and
METER
controls
may
be
disregarded
when
testing
eye
tubes
and
may
therefore
be
set
in
any
position,
9
he
ry the BIAS controi and observe the
w of the eye tube, Failure of the shadow
Mee, as the BIAS conirol is rotated
a defective tube, Failure of the eye
completely does NOT indicate a
ive tube but only means that the tube's
chara acteristics are "out of range" of the bias
values available,
ROLL CHART DATA
SBSegs
a %) p =
~ oO <e
eB
ee) ©
oli chart contains necessary data for the
5 of currently used tubes, But it is not
ossible to furnish a roii chart that
has all the latest tubes on it, because of the
PoP owat ott oT eT ee
constantly growing list of tubes and the time it
takes to obtain sample tubes, conduct tests, and
charts havatfars
publish r roll char ts, Therefor eG, to keep your roll
chart up-to-date, you may be interested in sub-
ih Mant Tiata CG <2s
scribing to the Heathkit Tube Test Data Service,
which will regularly supply you with the latest
rT Tex tha tn
data for newly released tubes, To subscribe to
nd in the Heathkit
e
ina Card
ce Vara
TESTING UNLISTED TUBES
The following procedure may be used as a guide
in datarmining cates uit cgottivecna
A GCter mining control and switch SCvLIgS for
testing tubes not listed on the roll chart or sup-
thiay, wae url
plement sheet, Testing a tube inthis manner will
show the tube to be either operative or inopera-
ats
ti ve, but will not indicate the degr ec ofo operative
condition, While there may be several com-
binations of control and switch settines that will
RRR ERR Ne AURA E UR CAAA OER ES DOULA LAL Wdd
produce a meter deflection, valid Gm readings
can be obtained only by that combination of set-
tings determined in the laboratory as correct
for that tube type, If several tubes of the same
type are available, they may betested ona com-
parison basis to determine which has the greater
amplification under a given set of test conditions,
SELECTOR Switch Positions
The SELECTOR switches corres
Mer Wes
pins, reading left to right,
pond to tube
top. to bottom,
Position
0
-
The
tube
pin
is
disconnected
from
all
voltage
supplies
and
all
other
tube
pins,