Heathkit IG 5257 Manual

Page 1

HEATHKIT®
MANUAL

HEATH COMPANY - BENTON HARBOR, MICHIGAN

Page 89

-HEATHKIT

Page 87

AMPLIFIER AND OSCILLATOR SECTION (Cont'd.I

SYMPTOM

Excessive marker
or unable to turn
marker completely
off with Marker

.-

CAUSE

Incorrect value of capaci-
tor C86.

Check capacitance value and
correct any errors.

Marker control is ad-
vanced.

SWEEP SECTION

control wiring.

control.
No trace. 1. Defective marker or trace la. Check all wiring around Q20.
amplifier. Also check Q20.
lb. Check for shorted capacitor
CB4 or other defective compo-
nents.
Excessive noise (hash) 1. TranSistor Q17, 1. Replace detective transistors.
on trace or marker. Q18, Q19 or QZO,
I Noise increases when 2. Incorrect Trace or Marker 2. Check wiring from Trace and

Marker controls to amplifier
circuit board.

- - -
SYMPTOM CAUSE CURE
- -

No control of sweep 1. Poor solder connections 1. Check and resolder D and X.
width or voltage at D or X on circuit board.
at TP3 (emitter of 2. Open L15 winding in con- 2, Measure resistance (rom lead
Q23)_ trollable inductor. Resist- to ground, Replace inductor i1

ance from D to ground winding is open.
NOTE: Be sure the should be 500 $1 $15%.
shield lead of the 3. Transistor Q23 shorted or in- 3. Check Q23. Replace if neces-
short 75 S? coaxial correctly connected. sary.
cable is soldered 4. Capacitor C2090r C211. 4. Replace C209 or C211.
securely in hole .1 5. incorrect wiringto sweep shield 5. Check and correct wiring.
and to the control connections.
solder lug at the 6. Incorrect wiring to Sweep Width 6. Check and correct wiring.
Sweep Output and Sweep Center controls or
connector. Sweep Range switch.
No horizontal 1. Incorrect wiring to Trace Re- 1- Check and correct Wiring.
deflection of verse switch.
oscilloscope 2. Capacitor C228 or C229. 2. Replace capacitor C228 or C229.
trace. 3. Incorrect wiring to 7-lug termi- 3. Check terminal strip connec-

nal strip. tions and wiring.
No sweep when l. Defective wiring or shorted 1. Check and correct wiring in
using Demodulator Demodulator or RF cable. defective cable.
or RF cables. 2. Diode in Demodulator cable. 2. Replace diode.

Page 106

Page 104

()Refer to Figure 26 and mount a. phono
socket as shown.

PHONO SOCKET

REAR 0F
FRO!"
PANEL

)9

Ill" FLA! WASH!
SOLDER lUG

\

FLAT WASHEI

Flguro 26

( ) Raster to Figure 2'! to find where the lug tor
the "high side" at the attenuator control is
located.

( ) Connect a 1000 n (brown-black-red) resis-

tor from the "high side" lugofthe attenuator
control (8-1) to the center lug o! the phone
socket (DB).

( ) Connect a75n(violet-green-hlack) resistor
from the center lug of the phono socket (8-2)
to the ground lug of the phono socket (NS).

( ) Connect a ground wire from the solder logo!
the phone socket (8-2) to the ground lug of
the RF Output connector (8-1).

SWEEP
SAMPLE
OUTPOY

MODIFYING LOW FREQUENCY OSCILLATOR

NOTE: 111s sweep range at some generators is
not low enough to cover the color bandpass range
of a color TV receiver. The sweep range of the
generator can be lowered by adding a capacitor
across the low frequency band oscillator coil in
the generator.

( ) Refer to Figure 28 for the oscillator coil
circuitry of the Heathkit Models 'l'S-d,
TS-4A, and 16-52 Television Alignment
Generators.

L V! FREQUENCY COIL

'UIILE

o , o nun suns»
A O 0 «Ion nun res.

Flgure 28

( ) Connect a 20 to 50 pF capacitor across the
low frequency oscillator coil as shown.
This will lower the frequency range ofthese

MODIFICATION FOR
HEATHKIT GENERATORS
TS-4.TS-4A.AND 16-52

generators.
. mn . Jo MARKER
1- fimpurlan
60

600
Mn

0 O ATTENUATION
"n O swu'rcu
on O O
7.

, ?

Figure 27