Fostex A-8 - Page 21

is reversed.
4.10 RECORD INDICATION
The RECORD indicating LED either 'blinks or lights constantly when the RECORD
and PLAY buttons are simultaneously depressed.
1) Blinking
By switch on of Q6 by the "L" level transport record signal, an "H" level is
applied to the base of QB to switch it on but as the emitter of Q8 is connected
to the collector of Q4 via D5, Q8 will switch on and off in step with Q4 and the
LED thus blinks.
2) Constant lighting
When any one of the RECORD TRACK button is depressed under the above 1) state,
the emitter of Q7 is connected to zero volt by the selected button which switches
it on and the LED is lighted in the constant state.
4.11 RECORD TRACK SELECT (Record/reproduce amplifier control circuit)
U6-11 is an exclusive OR gate. Each time the GROUP select switch is manipula 
ted, the output of U6-11 goes to "H" to switch on Q3 and an "L" pulse is applied
to the System Control LSI.
Due to this, the record mode is cancelled by switching of the GROUP selector
even if the LSI is in the record mode.
An encode/decode switching, record relay control and bias on/off control sig
nals are sent to the Record/Reproduce Amplifier from the RECORD TRACK select cir 
cuit.
As the circuits of track 1 through 8 are all identical, track 1 only will be
taken as an example.
When GROUP 1 t 4 is selected, input U6-9 is set to "H" and the output U6-10
goes to "L" level (if U6-9 is "L" , then U6-10 goes to "H").
When inputs U7-8 and U7-9 are at "L" , output 07-10 goes to "L", or in other
words, when the RECORD TRACK 1 button is depressed and the transport is in the
record mode.
By the "L" level of U7-10, 03-11 goes to "L" , and. the "L" from U3-10 applied
to 01-2 makes output Ul-3 go to "L" which is the encode mode signal. After a cer 
tain delay, introduced by the integration circuit of R14 and C5, Ul-4 goes to "L"
which makes both Ul-11 and 01-10 go to "L" level.
When either U7-8 or 07-9 goes to "H" level, U7-10 will go to "H" , then as
Ul-4 first goes to "H" , Ul-11 goes to "H" (bias off) , then, after a delay intro 
duced by R14 and C5, 01-10 goes to "H" (record relay off) and after another delay
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