Heathkit IT-12, Инструкция по сборке, Страница: 6 / 30

Page 4
CONSTRUCTION NOTES
This manual is supplied to assist you in every way to complete the instrument with the least possible chance for error.
We suggest that you take a few minutes now and read the entire manual through before any work is started. This will
enable you to proceed with the work much faster when construction is started. We suggest that you retain the manual in
your files for future reference, both in the use of the instrument and for its maintenance.
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 may be a question. If some shortage is found in checking the parts, please
notify us promptly.
Resistors generally have a tolerance rating of 10 unless otherwise stated in the parts list. Therefore a 100 KΩ resistor may
test anywhere from 90 KΩ, to 110 KΩ. (The letter K is commonly used to designate a multiplier of 1000.) Tolerances on
condensers are generally even greater. Limits of +100 and -20 are common for electrolytic condensers. The parts
furnished with your Heathkit have been specified so as to not adversely affect the operation of the finished instrument.
The Signal Tracer is not difficult to construct but it is extremely important that particular emphasis be placed on the
desirability of following parts placement and wiring dress as shown in the manual. This is important in order that the
operation of the Signal Tracer be hum free and that a motor boating condition is not induced. The wiring dress and parts
layout in the manual has been proven thoroughly satisfactory through the construction of a series of laboratory models.
While the arrangement shown is probably not the only satisfactory layout, it is the result of considerable experimentation
and trial. If followed carefully, it will result in a stable instrument operating at a high degree of accuracy and
dependability.
We suggest you do the following before work is started:
1. Attach the large fold-in pictorials to the wall above
your workbench.
2. Go through the entire assembly and wiring
instructions. This is an excellent time to read the entire
construction section through and familiarize yourself
with the procedure.
3. Lay out all parts so that they are readily available.
Refer to the general information inside the front and
back covers of this manual to help you to identify
components
Most kit builders find it helpful to separate the various parts
into convenient categories. Muffin tins or molded egg cartons
make convenient trays for small parts. Resistors and capacitors
may be placed in the edge of a piece of corrugated cardboard
until they are needed. Values can be written on the cardboard
next to each component. The illustration shows one method that
may be used.