Heathkit SG-8 Assembly And Operation Manual page 6

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We strongly urge that you follow the wiring and parts layout shown in the manual. The position
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A unique design feature is the convenient AF IN-OUT control, which adjusts audio input if ex ­
ternal modulation is employed and likewise adjusts theAF output level when using the generator
as a source of audio output.
PRELIMINARY INSTRUCTIONS AND NOTES
The Heathkit model SG-8 Signal Generator when constructed in accordance with the instructions
in this manual, is a high-quality piece of test equipment, capable of years of trouble-free serv ­
ice. We therefore urge you to take the necessary time to assemble and wire the kit carefully.
You will be rewarded with a neat appearing, well-built and dependable test oscillator.
In order to expedite delivery to you, we are occasionally forced to make minor substitutions of
parts. Such substitutions are carefully checked before they are approved, and the parts sup ­
plied will work satisfactorily. By checking the parts list for resistors, for example, you may
find that a 2.2 megohm resistor has been supplied in place of a 2 megohm as shown in the parts
list. These changes are self-evident and are mentioned here only to prevent confusion in check ­
ing the contents of your kit.
UNPACK THE KIT CAREFULLY AND CHECK EACH PART AGAINST THE PARTS LIST. In
so doing, you will become acquainted with each part. Refer to the charts and other information
shown on the inside covers of the manual to help you identify any parts about which there maybe
a question. If some shortage is found in checking the parts, please notify us promptly and return
the inspection slip with your letter to us. Hardware items are counted by weight, and if a few
are missing, please obtain them locally if at all possible.
The power supply consists of a transformer which furnishes filament voltage to the 6C4 and
12AU7 tubes, and effectively isolates the instrument from the AC line. A selenium rectifier is
connected to one winding of the transformer producing half-wave rectification. An RC filter
network changes the pulsed output from the rectifier to fairly pure DC. The 110 volt input has
both sides bypassed to minimize the signal feeding back through the power lines.
This manual is supplied to assist you in every way to complete the signal generator with the
least possible chance for error. We suggest that you take a few minutes now and read the en ­
tire manual through before any work is begun. This will enable you to proceed with the work
much faster when construction is started. The large, fold-in pictorials are handy to attach to
the wall above your work space. Their use will greatly simplify the construction of the kit .
These diagrams are repeated in smaller form within the manual. We suggest that you retain
the manual in your files for future reference, both in the use of the signal generator and for its
maintenance.
Resistors and condensers generally have a tolerance rating of ±20% unless otherwise stated in
the parts list. Therefore a 100 KQ resistor may test anywhere from80Kf2 tol20KQ. (The let ­
ter K is commonly used to designate a multiplier of 1000.) Tolerances on condensers are gen ­
erally even greater. Limits of +100% and - 0% are common for electrolytic condensers. The
parts furnished with your Heathkit have been specified so they may not adversely affect the op ­
eration of the finished signal generator.
Read the note on soldering on the inside of the back cover. Crimp all leads tightly to the termi ­
nal before soldering. Be sure both the lead and the terminal are free of wax, corrosion, or
other foreign substances. Use only the best rosin core solder, preferably a type containing the
new activated fluxes, such as Kester ' ' Resin-Five, " Ersin ' ' Multicore, " or similar types.
NOTE: ALL GUARANTEES ARE VOIDED AND WE WILL NOT REPAIR OR SERVICE
INSTRUMENTS IN WHICH ACID CORE SOLDER OR PASTE FLUXES HAVE BEEN
USED. WHEN IN DOUBT ABOUT SOLDER, IT IS RECOMMENDED THAT A NEW
ROLL PLAINLY MARKED ' ' ROSIN CORE RADIO SOLDER " BE PURCHASED.