- Safety---Safe servicing. Safety considerations with respect
to picture tubes. How great is implosion risk? How implosions occur. Skin
tension of glass. How to avoid causing an implosion. How to handle picture
tubes. Cautions for minimizing implosion injuries. Using safety goggles. Disposing
of unwanted tubes. How to deactivate a picture tube. X-ray radiation. Avoiding
TV shock. Aquadag grounding strap. Radio shock hazards. Degree of shock. Avoiding
- Tube and component damage---Tube
mountings. Positioning of rectifier tubes. Preventing damage to low-voltage
rectifier. Plate and screen dissipation ratings. Ventilation. Avoiding damage
to horizontal output tube. Cautions on high voltage rectifiers. High-voltage
lead dress. Protecting c-r tubes. Tube damage due to grid emission. Grid-to-ground
resistance. Premature tube failure due to leaky coupling capacitor. Miscellaneous
sources of arc-caused damage to tube and components. Series-filament circuits.
Cautions on use of tube testers.
- Tube troubles in tv---Localizing
defective tube when raster and sound are absent. Raster absent, sound normal.
Raster absent, hum in sound. Cathode-to-heater short. Intermittent raster.
Excessive warmup time. Size, linearity and brightness troubles. Insufficient
width due to tube troubles. Reduced line voltage. Vertical deflection absent.
Insufficient height. Intermittent vertical collapse. Vertical shrinking.
Increasing height by tube substitution. Vertical non-linearity. Horizontal
nonlinearity. Insufficient brightness. Excessive brightness.
- Picture and sound troubles---Pix
absent, sound and raster normal. Pix and sound absent, raster normal. Intermittent
pix and sound. Pix and sound reception absent on some channels. Receiver
inoperative on uhf. Pix missing; sound is strong. Insufficient signal. Snow.
Weak uhf reception. Overloading. Negative picture. Poor definition. Resolution
troubles. Picture smear. Engraved effect. Ghosts. Buzz. Other sound troubles.
Sound absent, pix normal. Weak and/or distorted sound. Noisy sound. Noise
drowns out desired sound. Sound and pix do not track.
- Sync troubles---Vertical
sync trouble. Rolling due to 6BL7-GT characteristics. Tube substitutions
to improve vertical stability in weak-signal areas. Vertical jitter due
to lead dress. Vertical blanking bar in pix. Single vertical pix unobtainable.
Poor interlace. Horizontal sync trouble. Horizontal sync instability. Horizontal
pulling. Horizontal tearing. Horizontal jitter. Symptoms associated with
controls. Horizontal sync symptoms. Improving horizontal sync stability.
Flashes in picture.
- Interference---TVI. Radiation from horizontal output
Barkhausen oscillation. Vertical-line troubles. Vertical lines due to improper
lead dress. Vertical white line due to failure of horizontal retrace blanking
tube. "Spook" interference. Radiation from audio output tube. "Snivets".
Microphonics. Sound in pix. Hum bars in picture and raster. Corona and
arcing. Localizing corona. Arcing inside the at. Arcing at metal C-R tubes.
Arcing due to improper crt grounding.
- Picture tubes---Bulb and base differences. Aquadag coating.
Glass vs. metal tubes. Picture-tube lengths. Electrostatically and electromagnetically
deflected picture tubes. Yoke and focus problems. Centering devices. Ion-trap
systems. Damage due to misadjusted ion-trap magnet. Testing and repairing
picture tubes. Possible troubles in picture tubes. Loss of emission. Rejuvenation.
Cathode defects. Gassy tubes. Filament troubles. Heater-to-cathode shorts.
Grid-to-cathode short. Magnetized metal picture tube. Universal picture
- Radio tube troubles---Intermittent filament troubles.
Station drift. Receiver volume below normal. Distortion. Hum. Hum due to
heater-to-cathode leakage. Modulation hum. Hum due to cathode-to-heater
short. Filament-to grid coupling. Tube shields and hum. Lead-dress hum.
Socket trouble. Obscure causes of hum. Tube-caused buzz. Oscillation. Micro
phonic tubes. Noisy tubes. Tube troubles in portable radios. Avoiding tube
damage. Intermittent operation and fading. In-operation. Distortion. Low
volume. Miscellaneous symptoms.
- Tube replacements---Precautions in making tube substitutions.
Salvaging the diode-triode. Replacing tuner tubes. Improving reception
through tube substitutions. Replacing rf oscillator tubes. Video if tube
replacements. Sweep and sync tube replacements. Tube design. Horizontal
output tubes. Substitution rules. High- and low-voltage rectifier tubes.
Replacing Parallel rectifiers. Avoiding needless picture tube replacements.
Re-necked picture tubes. Electrostatic-focus picture-tube substitutions.
Retaining salvage value of the picture tube. Tube replacement notes.
TUBE faults are, by far, the most frequent ones encountered by the TV-radio
technician; he runs into them in perhaps 70% (and quite possibly more) of
his service jobs. Even the best service technician not infrequently spends
an undue number of minutes in localizing some tube defect; less experienced
men may waste one or two hours in tracking down some tube-caused faults. The
author recalls a case in which a service technician spent several hours in
tracing a condition known as "Christmas-tree effect" to a weak video
amplifier tube. It had just never occurred to the man to link this particular
cause and effect together. Numerous similar in stances could be cited. This
guide is intended to minimize such roundabout troubleshooting.
The reader will find here an organization of TV and radio tube troubles,
both familiar and unfamiliar, into a handy form that permits fast reference
to needed information. TV-radio service data form a peculiarly elusive body
of knowledge in the average technician's mind; information he hasn't used
for some time is quite likely to slip away and be missing when it is needed
This guide is intended to act as a memory guide with respect to tube troubles
when fast refreshing is needed. The author hopes that even advanced service
technicians will find material here with which they are unfamiliar.
A guide of this type should prove most valuable for less experienced service
technicians and beginners. The outside service technician with a sketchy technical
background will find it very helpful; so will the shop owner or manager who
wants to train--or increase the efficiency of--a home service technician.
The intent of the guide is not only to speed tube troubleshooting directly--it
also aims to do so indirectly, by presenting a wealth of service data about
tubes. The author knows of no other book, incidentally, that covers this territory.
The author and publishers acknowledge with thanks the cooperation of the
following companies during the preparation of this book: Admiral Corp., DeWald
Radio Mfg. Co., Allen B. DuMont Laboratories Inc., Emerson Radio & Phonograph
Corp., General Electric Co., Hoffman Electronics Corp., The Magnavox Co.,
Motorola Inc., Packard Bell Electronics Corp., Philco Corp., RCA, RADIO-ELECTRONICS
Magazine, Radio dr Television News, Sylvania Electric Products Inc., Technician,
Traveler Radio Corp., Westinghouse Electric Corp., Zenith Radio Corp.
Soft cover design by Muneef Alwan; Cover design of the clothbound edition
by Thomas Falletta
Air Time--An Intro to Television Broadcasting
Video Handbook (1954)