Heathkit IT 17 Manual 2

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SPECIFICATIONS

Tube Socket Accommodations . . . . . . . . . . . .

Controls. . . . .

Element TestVoltages.................

Filament Voltages. . . .

RollChartMechanism..................

Line Voltage Adjustment. . . . . . . . . . . . . . . .

Meter

Tests Available.....................

PowerRequirements..................
DimensionS........................

NetWeight..........

4 - pin.

- pin.

- pin Nuvistor.

- pin.

- pin combination and pilot lamp.
- pin miniature.
pin Nuvistor.

- pin octal.

- pin loctal.

- pin miniature.

- pin Novar.

pin miniature.
pin Compactron.

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I

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NO
11

FILAMEN'I VOLTAGE
SET LINE

TYPE

PLATE

30, 100, and 250 volts AC.

.63, 1.4, 2, 2.35, 2.5, 3.15, 4.2, 4.7, 5, 6.3, 7.5,
9.45, 12.6, 19.6, 25, 32, so, 70, and 110 volts AC.

Constant tension, free rolling, thumbwheel oper-
ated, illuminated.

Step type.

1 milliampere full scale, BAD - ? - GOOD
scale, illuminated.

Emission, Short, Leakage, Open Element, and
Filament continuity.

105-125 volts 50/60 cps AC.
13" wide x 8-1/2" high x 5-1/2" deep.
9 lbs.

The Heath Company reserves the right to
discontinue instruments and to change speci-
fications at any time without incurring any
obligations to incorporate new features in in-
struments previously sold.

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above mentioned testing procedures to follow,
Points that must be considered are the cost,
relative merits of each system, and the net
value to the purchaser. On the basis of these
and other considerations, the HEATHKIT Tube
Checker has been designed around the emission
testing circuit. There are several reasons
for this decision, some of which are: (1) the
emission checker will provide the best overall
indication of tube quality when compared with
other types on a cost per unit basis, (2) the
transconductance of a tube is dependent upon
cathode emission, (3) some busy servicemen do
not wish to take the time necessary to check the
tube thoroughly. They plug in the tube, push the
button and observe the meter to checkthe emis-
sion; if the emission of the tube is too low for
the intended service, determining any of the
other characteristics is a waste of valuable
time, (4) the emission testing circuit is rela-
tively simple, requires few components, and
lends itself well to kit-type construction, and (5)
the low selling price made possible by the use
of this circuit more than compensates for any
inherent shortcomings it may possess. We sin-
cerely believe the HEATHKIT Tube Checker
will give the most test information per dollar
invested.

The action of the instrument has been made quite
flexible by the use of multiple filament voltages,
adjustable cathode current, variable meter sen-
sitivity and individual element switching. The
thirteen lever switches make it possible to con-
nect any element to any other element, regard-
less of the pin numbers involved.

The instrument may be used in darkened areas
(such as the inevitable dark corner behind the TV
receiver) with ease since both the roll chart and
the meter are illuminated.

No difficulty should be experienced in roll chart
operation on the part of the left-handed operator.
Thumbwheel drive knobs have been provided on
both sides of the panel to eliminate any "cross-
over" problems. The roll chart mechanism is a
unique design which permits the roll chart to
run freely throughout its entire length without
binding. The chart rollers are spring loaded to
keep the chart taut at all times to present a
smooth viewing surface.

TUBE TYPE ACCOMMODATIONS

The HEATHKIT Tube Checker was designed for

checking tubes encountered in everyday radio
and TV service work, but is not specifically
limited to these types. It will check satisfactor-
ily any tube that canbe accommodated inthe tube
sockets if the data provided by the tube manu-
facturer is available. Sockets provided are:
4-pin, 5-pin, 5-pin Nuvistor, 6-pin, 7-pincombi-
nation and pilot lamp, 7-pin miniature, 7-pin
Nuvistor, 8-pin octal, 8-pin loctal, 9-pinNovar,
10-pin miniature, and 12-pin Compactron.

The 10-pin miniature socket is constructed so
that it can also be used to check 9-pin miniature
tubes.

ROLL CHART DATA

The roll chart contains necessary data for the
checking of currently used tubes. But it is not
always possible to furnish a roll chart that has
all the latest tubes on it, because of the con-
stantly growing list of tubes and the time it
takes to obtain sample tubes, conduct tests,
and publish roll charts. Therefore, to keep your
roll chart up to date, you may be interested in
subscribing to the Heathkit Tube Test Data Ser-
vice, which will regularly supply you with the
latest data for newly released tubes. To sub-
scribe to this service, fill out and send in the
Heathkit Tube Test Data Service Card.

FILAMENT VOLTAGES

Filament voltages used in the operation of the
tube checker are derived from a secondary wind-
ing on the power transformer which is tapped to
provide nineteen different voltages. These volt-
ages are switch selected for convenience of oper-
ation and assure the application of the proper
filament voltage for a given tube type under test.

TEST VOLTAGES

Voltages used in the various tests provided by
the Tube Checker are derived from asecondary
winding on the power transformer which is tapped
at 30, 100, and 250 volts.Duringthe operation of
the Checker, three basic circuits are set up
using these voltages.

LINE TEST CIRCUIT

The first basic circuit, Figure 1, is inuse when
the TEST switch is in the SHORT ADJUST posi-
tion. The SET LINE switch in the primary of the
power transformer varies the voltage across
the primary, thus controlling the voltage across
both secondary windings simultaneously. The