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JLJI JL |-JLJL JLJLJI JL,I. JL
Note the line from C to E: this can be plotted as the trip current for
varying stabilized voltage setting of VR1 - the pecked trace shows
the current/voltage curve at 20V.
EC5
Connections
Input. The PZ8 requires an input in the region of 40v ac, which must
be supplied from a transformer.
A suitable transformer will be rated at 24 continuous, with an
o u t p u t v o l t a g e o f n o t m o r e t h a n 4 5 v m a x i m u m . l f t h e o u t p u t v o l t a g e
i s r e d u c e d t h e n t h e i n p u t c a n b e r e d u c e d a l s o . I n p u t v o l t a g e c a n b e
m a d e u p t o 2 0 o / o l e s s t h a n t h e r e q u i r e d o u t p u t v o l t a g e . A s u i t a b l e
t r a n s f o r m e r i s t h e M T l 0 4 o r 1 0 5 . a v a l l a b l e f r o m H e n r y ' s R a d i o a n d
most other component retailers.
O N N O A C C O U N T M U S T M A I N S B E C O N N E C T E D D I R E C T T O
T H E P Z 8 .
40V ac inout connects to the terminals on the PZB marked
Output. + ve and
ve outputs are marked + and -.
The -ve
outDut is connected to the heatsink,
ECO Voltage Adjustment
The PZ8's voltage is adjusted by means of VR1, between a maxi-
mum of about 6Ov and 20v minimum. A voltmeter is required to
measure the output voltage if this is readjusted.
EC7 Mounting and Heatsinking
PZB's mounting and heatsinking requirements are the same as those
of the 260, covered in Section D6.4 and A1.2.
EC10 Common faults
Failure of the PZ8 is rare because of its sophisticated protection
clrcuitry.
No output. PZ8, working into a damaged Z6O, may detect this
damage and shut itself off, giving no output. This does not indicate a
fault in the PZ8. Disconnect one or other 260 to locate the fault.
Overheating. The PZ8 will overheat if heatsinking is not adequate:
see Sections A1 .2 and D6.4.
An area of copper on PCB has overheated. The PZB has two thin
sections of copper on its board, in series with the rectifier, to act as
f uses. These can only fail if the rectifier is destroyed. When replacing
the rectifier, these can be bridged over with one strand from a
7/0016 flexible wire (fuse rating about 7,A).
F
FA
Other Parts
P.805 Masterlink
FA1
Description
The P.805 masterlink contains input sockets for pickup, radio and
tape recorder connections, and speaker output sockets, with con-
necting points for the other modules in the project.
30
FA 3
Masterlink laYout
It also has alternative connections, by means of push-fit wires, for
p i c k u p , w h e n t h e w h o l e p r o j e c t i s t o b e p l i n t h - m o u n t e d . F a c i l i t i e s
are also provided for connection of headphones.
The masterlink also contains decoupling capacitor for use with the
t u n e r ( s e e S e c t i o n 8 6 . 1 ) a n d a t t e n u a t o r s ( v a r i a b l e r e s i s t o r s ) f o r r a d i o
and tape recorder inputs to the Stereo 80. lt also contains resistors in
p i c k u p i n p u t f o r u s e w i t h h i g h o u t p u t c a r t r i d g e s .
FA3
Layout
N o t e R V 1 a n d R V 2 a r e n o t i n c l u d e d i n t h e ' m a s t e r l i n k w h i c h i s
matched to the P.80 tuner. lf a different tuner, with a higher output,
i s u s e d , R V l a n d R V 2 c a n b e a d d e d . U s e 4 7 K p o t s ,
R3,4,5 & 6 are not fitted: space is left so that a PZ6 or PZB can be
used (subject to laboratory testing) at a later date.
Appendix
Service and guarantee
All Sinclair Project 80 modules are covered by a 24 month guarantee
d u r i n g w h i c h t i m e w e w i l l r e c t i f y a t n o c h a r g e , a n y f a u l t w i t h i n t h e
m o d u l e w h i c h i s n o t c a u s e d b y m i s u s e , s u b i e c t t o t h e f o l l o w i n g
c o n d i t i o n s .
1 . T h e i t e m m u s t b e r e t u r n e d a s a m o d u l e
i . e . n o t w i r e d i n t o t h e
customer's own box -
direct to us, properly packed so as to
a v o i d d a m a g e .
2 . A l e t t e r m u s t b e i n c l u d e d s t a t i n g y o u r n a m e a n d a d d r e s s ( b l o c k
c a p i t a l s p l e a s e ) , w h e r e a n d w h e n p u r c h a s e d , t h e n a t u r e o f t h e
f a u l t .
3. The item must not have been damaged by misuse or inexpert
attempts at repair, or have been modified either electrically or
m e c h a n i c a l l v f r o m t h e c o n d i t i o n s i n w h i c h s u p p l i e d , o t h e r t h a n a s
d e s c r i b e d i n t h i s m a n u a l .
Please note that we cannot undertake to answer letters sent in
with equipment for repair, although every effort will be made to
o o s o .
U n d e r n o c i r c u m s t a n c e s c a n w e a c c e p t e q u i p m e n t b a c k w i r e d u p
unless a previous agreement has been made in writing.
We regret we cannot undertake to service equipment brought in
p e r s o n a l l y , w h i l e - y o u - w a i t , u n l e s s a n a p p o i n t m e n t h a s b e e n
m a d e i n a d v a n c e .
Where the equipment is not covered by the guarantee for any
reason we will normally be able to service on a standard charge
basis. The standard charges are f1.50 each for 240 and 260 and
12.00 each for all other modules. These prices do nor include VAT
which must be added. This fee should be sent with the item for
r e D a l r .
Spare parts are available for those who wish to do their own
service - price lists are available on request. Cash with order only
prease.
Naturally spares are free if evidence is shown that the failure is
u n d e r g u a r a n t e e .
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