Tait T850 II Series, Service Manual

Page: 201 / 370

M850-00
T856/857 PCB Information C6.1.5
Copyright TEL 31/09/98
Variant Components
A variant component is one that has the same circuit reference but different value or specification in
different product types. Where two products share the same PCB, the term “variant” is also used to
describe components unplaced in one product. Variant components have a character prefix, such as
“&”, “=” or “#”, before the circuit reference (e.g. &R100).
The table below explains the variant prefixes used in T800 Series II products:
Grid Reference Index
This section contains a component grid reference index to help you find components and labelled
pads on the PCB layouts and circuit diagrams. This index lists the components and pads in alpha-
numeric order, along with the appropriate alphanumeric grid references, as shown below:
If the variant prefix is. . . the component will. . .
& change according to channel spacing
= change according to frequency stability
# change according to frequency range
% be placed or unplaced for special applications
*
be unplaced in one product
(where two products share the same PCB)
circuit diagram
reference
PCB layout
reference
components listed
in alphanumeric order
layer number -
1 = top side layer
2 = bottom side layer
component location
on the layer
sheet number
component location
on the sheet