Harris GATES M-6035 User manual

1USTRUCTION
EGUK
INSTRUCTION BOOK
FOR
M-6035 CUE- INTERCOM AMPLIFIER
88 - 108 MC
r1=-71
tib
Q d eizià ; ES
Juno 1965
GATES RADIO COMPANY • QUINCY, ILLINOIS e 62301 o U.S.A.
A Division of Harris-Intertype Corporation

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INSTALLATION AND OPERATING 1.1STRUCTION
FOR M-6035 CUE- INTERCOM AMPLIFIER
•
GAIN:
FREQUENCY
RESPONSE:
HARMONIC
DISTORTION:
NOISE:
SOURCE
IMPEDANCE:
OUTPUT LOAD
IMPEDANCE:
MAXIMUM INPUT
LEVEL:
MAXIMUM OUTPUT
LEVEL:
TECHNICAL DATA
86 DB ± 2 DB @ 1 KC
Variable - Requires 10K varia-
ble resistor. ( Part of Console)
Peaked for maximum intelli-
gibility.
Under 4% at + 28 DBM (. 6 W)
at mid- band frequencies.
-105 DBM equivalent input
noise.
45 Ohms.
45 Ohms. ( High Impedance
Speaker)
-40 DBM.
+30 DBM.
MAXIMUM OPERA-
TING AMBIENT
• TEMPERATURE: 55° C. ( 131° F.)
MAXIMUM STORAGE
AMBIENT
TEMPERATURE: 85° C. ( 185° F.)
POWER REQUIRE-
MENTS: - 37 V. DC ( unregulated)
10 - 75 ma.
• TRANSISTORS: 1 - 2N214 2 - 2N1183
3 - 2N1414 1 - 2N5088
1 - 2N5087
SIZE: 3-1/4"Wide x 7-1/2*Long
x 1" Thick.
DESCRIPTION
The Gates M-6035 Transistor Cue- Intercom Ampli-
fier is designed to be used in transistor consoles
for cueing and talkback purposes. The amplifier
utilizes a gain control for adjusting to different
input levels. The amplifier is designed to be fed
from a 45 ohm source and to operate into a 45 ohm
speaker or resistive load.
The amplifier is designed to be used with the
M-6039 mounting frame, which carries a mating re-
ceptacle for the printed card type connection. The
connections on the printed wiring board are gold
flashed for positive connection with the gold con-
di tacts on the mating receptacle.
WThe amplifier requires a - 37 V. DC unregulated
power source and requires from 10 iña. ( at average
power output) to a maximum of 75 ma. ( at + 28 DBM
output).
THEORY OF OPERATION
For the purpose of explanation, the Cue- Intercom
Amplifier can be considered to be made up of two
distinct parts: The preamplifier, and the power
amplifier.
THE PREAMPLIFIER
The two stage preamplifier is driven by an input
transformer which is somewhat loaded by the in-
put resistor. This resistor prevents excessive
signals from being developed by the speaker at its
resonance frequency, which would over- drive the
input stage. Both stages are of the common emitter
configuration, with direct coupling utilized between
the stages. On the schematic, 837 9345 001, it
should be noted that Q1 is a NPN type transistor
and has its emitter returned to B- for biasing pur-
poses.
Biasing is. accomplished by a combination of volt-
age divider and emitter resistance as with R1, R2
and R5. This method of biasing also insures a high
degree of temperature stability. Signal degenera-
tion is also for Q2 by R7.
The volume control, ( located on the console) situa-
ted between the preamplifier and power amplifier,
is connected in reverse, to maintain the high
source impedance at all settings that the power
amplifier requires.
THE POWER AMPLIFIER
The output stages of the power amplifier operate
Class B, and are arranged in the circuit configura-
tion known as " single ended push-pull", or " follow-
ed emitter follower". The upper and lower units are
in series across the power supply, and the load is
connected at their junction, when the signal at the
collector of Q4 goes negative Q6 and Q8 conduct,
since they are all PNP types. When the signal goes
positive Q5 and Q7 conduct since Q5 is a NPN type.
Thus, the full signal appears at the junction point.
Note that Q4 is the only stage in the power ampli-
fier with this voltage gain. A high frequency trans-
istor is used at this point to improve stability.
Several feedback loops are employed in this cir-
cuit, including R10, C7, C10, and C9, C7 and C10
provide high frequency stability, C12 supplies posi-
tive feedback from the output to the collector cir-
cuit of Q4 to increase the signal handling capability
of this stage.
MAINTENANCE
PREVENTIVE MAINTENANCE
The M-6035 Cue- Intercom Amplifier is designed for
long, trouble- free service. However, as with all high
quality electronic equipment, a regular program of
inspection should be followed.
It is recommended that when the amplifier is first
received, part of the console, D.C. voltage be
measured with the same voltmeter that will be used
for maintenance and troubleshooting, and these

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2
readings be recorded on the amplifier schematic a-
bove the typical voltages shown.
SERVICING
When servicing the amplifier, the following points
should be observed.
1. The condition of the output stage measuring the
speaker bus voltage at the junction of R21 and
the collector 6f Q8.
2. Circuit resistances should be measured only af-
ter removing the associated transistor or trans-
istors, to prevent damage due to ohmmeter bat-
tery voltage.
3. DO NOT remove or insert transistors with the
power ON.
4. DO NOT probe the printed board with a metal
probe with the power ON.
5. Circuit voltages are reversed from standard va-
cuum tube practice, as is the polarity of all
electrolytic capacitors.
6. The location of the positive end of each elec-
trolytic capacitor is indicated by the white dot
marked on the top of the circuit board.
PARTS LIST
Symbol No. Gates Stock No. Description
Cl, C2, C3,
C4, C9 522 0242 000 Cap., 25 mfd, 25 V.
C5 506 0005 000 Cap., . 1 mfd., 200 V.
C6 522 0178 000 Cap., 25 mfd., 6 V.
6 —
—37 ',' DC —
1T111NPUT —
(T1)1NPUT—
VOL. CONT. AR NI —
VOL . CONY • TOP —
11+60NO. RETUI:N —
OUTPUT —
•
—T 1 sccor4r.trr
GREEN
Ti 5E CONDARY
ILACK
Symbol No.
C7,
C8
C12
C13
C14
Q1
Q6
Q2,
Q3, Q4, Q5
Q7, Q8
Gates Stock No. Description
516 0054 000 Cap., . 001 mfd., 1KV, 10%
522 0256 000 Cap., 20 mfd., 50 V.
522 0246 000 Cap., 100 mfd., 25 V.
506 0006 000 Cap., . 25 mfd., 200 V.
506 0004 000 Cap., . 05 mfd., 200 V.
380 0115 000 Transistor, 2N5088
380 0011 000 Transistor, 2N214
380 0112 000 Transistor, 2N5087
380 0014 000 Transistor, 2N1414
380 0012 000 Transistor, 2N1183
121
R2, R3
R4
R5
R6
R7,
R8
R9, R19, R20
R10, R14
RII
R12, R18
R13
R15
R16
R23
R2,4
R21, R22
R25
R17
Tl
XD1, XD2
XQ1, XQ2,
XQ3, XQ4,
XQ5, XQ6
XQ7, XQ8
540 0081 000
540 0071 000
540 0076 000
540
0075 000
540 0057 000
540 0036 000
540 0045 000
540 0041 000
540 0073 000
540 0085 000
540 0039 000
540 0098 000
540 0049 000
540 0070 000
540
0017 000
540 0023 000
540 0005 000
540 0845 000
540
0025 000
478 02851)00
Res., 22K ohm, 1/2 W., 5%
Res., 8200 ohm, 1/2 W., 5%
Res., 13K ohm, 1/2 W., 5%
Res., 12K ohm, 1/2 W., 5%
Res., 2200 ohm, 1/2W., 5%
Res., 300 ohm, 1/2W.. 5%
Res., 680 ohm, 1/2 W., 5%
Res., 470 ohm, 1/2 W., 5%
Res., 10K ohm, 1/2 W., 10%
Res., 33K ohm, 1/2 W., 5%
Res., 390 ohm, 112W., 5%
Res., 110K ohm, 1/2 W., 5%
Res., 1K ohm, 1/2 W., 5%
Res., 7500 olun, 1/2W., 5%
Res., 47 ohm, 1/2 W., 5%
Res., 82 ohm, 1/2 W., 5%
Res., 15 ohm, 1/2W., 5%
Res., 6.8 ohm, 1/2 W., 5%
Res., 100 ohm, 1/2W., 5%
Transformer, Input
404 0227 000 Dissipator
404 0066 000 Socket
404 0149 000 Socket
Ti
01
' lo
03
05
4. C12
06
122
07
C13

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1
INSTALLATION AND OPERATING INSTRUCTIONS
FOR M-6034 TRANSISTOR PREAMPLIFIER
TECHNICAL DATA
GAIN: 45 DB ± 1 DB operated into a
600 ohm load.
FREQUENCY
RESPONSE: ± 1 DB, 30 cps to 15,000 cps.
HARMONIC
DISTORTION: Under 0.5% from 50 cps to 15
KC at + 5 DBM output.
Under 0.5% from 30 cps to 15
KC at.-- 50 DBM output.
INTERNIODULATION
DISTORTION: Under 0.5% at — 5 DBM output
level, and under 1.0% at + 5
DBM output level.
Distortion measured at equiva-
lent sine wave output using 40
cps and 7 KC mixed 4 to 1.
NOISE LEVEL: — 122 DBM equivalent input
noise.
SOURCE IMPEDANCE: 30/50 and 150/250 ohms.
INPUT IMPEDANCE: Input transformer unloaded, re-
sulting in input impedance
being substantially higher than
source impedance.
OUTPUT LOAD
IMPEDANCE:
MAXIMUM INPUT
LEVEL:
MAXIMUM OUTPUT
LEVEL:
600 ohms ± 10%.
—40 DBM.
+5 DBM.
MAXIMUM OPERATING
AMBIENT
TEMPERATURE: 55° C. ( 131° F.)
MAXIMUM STORAGE
AMBIENT
TEMPERATURE:
POWER REQUIRE-
MENTS:
TRANSISTORS:
MOUNTING:
85° C. ( 185° F.)
—30 V. DC at 15 ma with less
than . 1 MV ripple.
3 - 2N5087 1 - 40319
Requires M-6039 mounting
frame.
SIZE: 3-1/4" Wide x 6-3/8" Long
x 1" Thick.
DESCRIPTION
The Gates M-6034 Transistor Preamplifier is a premium
quality low noise unit for use in consoles, and is com-
pletely temperature conipensated using the latest tech-
niques. The amplifier has a gain of 45 DB with a maxi-
mum output is unbaraneed and transformerless, which
is designed to operate into a 600 ohm variable attenua-
tor.
The input is balanced, and is connected for 150/250
ohm source impedance at the factory but may be recon-
nected for 30/50 ohms.
THEORY OF OPERATION
This amplifier is designed to provide a fixed gain of
45 DB. It is a four- stage amplifier and utilizes a trans-
formerless output. It features negative feedback to re-
duce distortion to a very low level and minimizes
specification changes with transistor changes.
Signal is applied to pins C and E and is fed through
transformer, Ti, to the base of Q1 ( 2N1307). Q1 is a
low noise transistor operated at ideal collector current
for minimum noise. It will be noted that the first stage
is series fed through Ti to provide the maximum input
gain from Ti. Cl and R1 are connected across the secon-
dary of
Ti to stabilize the amplifier. The value of R1
and Cl were picked to provide a roll off above the audio
range to prevent amplification of very high frequency
noise.
The signal is then direct coupled from the collector of
Q1 to the base of Q2. Q2 . is a very high gain stage be-
cause the emitter is completely by-passed. The signal
is then coupled from the collector of Q2 ( thru C8) to
Q3. The collector of Q3 is direct coupled to the base
of Q4. Q4 is an emitter follower. Emitter followers
are very stable and are virtually distortionless. This
also provides the low output impedance required to
feed a 600 ohm fader. Feedback is applied from R17
through R13 and C9, R7 and C5 to the emitter resistor
(R6) of the first stage. R13 and C9 provide a boost of
1 DB at 30 cps to make the response flat in the audio
range.
MAINTENANCE •
Transistor amplifiers are designed for a long trouble-
free life, however, dust and dirt can cause trouble. A
monthly dusting with a soft brush should be adequate.
SHOULD TROUBLE OCCUR -
Step 1 - First check all DC voltages. The DC voltages
determine the bias points of the transistors
and any departure of 20% or more should be
considered a defect. NOTE: Use of the resis-
tance chart will help detect faulty components.
Step 2 - Before any signal measurements are made, re-
place any defective parts to make DC voltages
correct.
Step 3 - After all DC voltages are correct, signal tests
may be performed. The correct ( RMS) voltages
are shown on the schematic diagram. Voltages
shown are for — 40 DBM input 150 ohms not
terminated.
DO NOT remove or insert transistors with the power
ON.
Gates Radio Company
Quincy, Illinois

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REMEMBER - In this transistor circuitry B+ is
ground, therefore, capacitors have the
positive side connected to ground.
S NOT probe the printed board with the power ON
with a metal screwdriver, etc., that could short out
wiring.
If -
(-30V)
e+
(ORD )
IN
C.7
IN
OUTPUT
PI
TI PRIMARY
IMP.
1500.
500.
cr
vv
YEL. Il ONO
TS Jt.
V.,
To et • 1
OCT TO
IbluE e ERN.
154..VE • YEL
Symbol No. Gates Stock No. Description
Cl 508 oc349 000
C2 522 0178 000
C3 522 0160 000
C4, C7, C8,
C10 522 0242 000
C5 500 0759 000
C6 522 0187 000
C9 522 0158 000
Ql, Q2,
Q3 380 0112 000
Q4 380 0171 000
R1 540 0035 000
R4 548 0050 000
R3 540 0062 000
R5 540 0066 000
R6 548 0049 000
R7 540 0038 000
R8 540 0077 000
R9 540 0068 000
R10 540 00(34 000
R11 540 0081 000
R12 540 0062 000
R13 540 0025 000
R14 540 0084 000
R15 540 0048 000
R16 540 0063 000
R17 540 0036 000
R18 540 0058 000
R2 540 0076 000
Ti 478 0285 000
XQ4 404 0198 000
-14
Na -30
Cap., . 0075 uf, 100 V.
Cap., 25 uf, 6 V.
Cap., 100 uf, 3 V.
Cap., 25 uf, 25 V.
Cap. 100 PF, 500V.
Cap., 200 uf, 6 V.
Cap., 50 uf, 3 V.
Transistor 2N5087
Transi stiir - 10319 ( Selected)
Res., 2'70 ohm, 1/2W., 5%
Res., 20K ohm, 1/2 W., 1%
Res., 3600 ohm, 1/2 W., 5%
Res., 5100 ohm, 1/2 W., 5%
Res., 100 ohm, 1/2 W., 1%
Res., 360 ohm, 1/2 W., 5%
Res., 15K ohm, 1/2 W., 5%
Res., 6200 ohm, 1/2 W., 5%
Res., 4300 ohm, 1/2 W., 5%
Res., 22K ohm, 1/2 W., 5%
Res., 3600 ohm, 112 W., 5%
Res., 100 ohm, 1/2 W., 5%
Res., 30K ohm, 1/2 W., 5%
Res., 910 ohm, 12 W., 5%
Res., 3900 ohm, 1/2W., 5%
Res., 300 ohm, 1/2 W., 5%
Res., 2400 ohm, 1/2W., 5%
Res., 13K ohm, 1/2W., 5%
Transformer, Input
Transipad
I) DC VOLTAGE, ARC TYPICAL ANO WERE READ WITH A . 504PSbN EGO.
5) VOLTAGES 314044 AS (—) ARE SIGNAL VOLTAGES.
3) ALL Re5/5TORS I/O WATT, Sit EXCEPT •
4) ALL CAPACITORS IN 0400, WITH OC W V.
3.) 0 INDICATES SOLDER LUG

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dir
Fig. 1 - M5700 Transistor Program Amplifier
• The Gates Transistor Program Amplifier is
available in two versions:
I. The M5700 is designed specifically for
use in Gates Transistor Consoles. It is
supplied less the interstage level control,
and with the input unterminated. The con-
trol is mounted externally on the Console
panel.
2. The M5700B is designed for rack mount-
ing in system installations with the level
control mounted internally. The input of
the amplifier is unterminated to facilitate
application. Terminate the input connect -
ions on the amplifier mounting tray in the
proper resistance ( 150 or 600 ohms). The
gain of the M5700B will then be approxi-
mately 70 db maximum.
TECHNICAL DATA
Gain:
M5700: 80 DB, M5700B: 76 DB,
may be reduced as required with
internal volume control.
Frequency Response:
+ 1 db from 30 to 15,000 cps.
Harmonic Distortion:
Under 0.75% at 30 cps., 0.5% from 50
to 15,000 cps., at + 24 dbm output.
Intermodulation Distortion:
Under 0.3% at + 14 dbm equivalent sine
wave power output, using 40 and 7000
cps.., mixed 4:1. Under 1.5% at + 24
dbm.
Noise Level:
-122 dbm equivalent input noise.
Source Impedance:
150/250 ohms, or 500/600 ohms.
Input Impedance:
Factory connected for 150 ohms. May
also be connected for 600 ohms.

1
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1
Load Impedance:
Factory connected for 600 ohms. •
also be connected for 150 ohms.
te Maximum Input Level:
-35 dbm.
Maximum Output Level:
+24 dbm.
Maximum Operating Ambient Temperature:
55°C. ( 131° F.)
Maximum Storage Ambient Temperature:
85° C. ( 185° F.)
Power Requirements:
30 volts D.C., 90 ma., 0.1 mv.
maximum ripple.
Transistors:
4 - 2N1414 2 - 2N5087
1 - 2N1183
May
Finish:
Satin- silver cover, black
escutcheon plate.
Mounting:
M6031 Mounting Tray required to mount
in M6029 Shelf Assembly. Shelf assem-
bly accommodates seven Program Ampli-
fiers and requires panel space of 3-1/2"
X 19".
Size:
2-7/32" wide, 3-1/8" high, 10-3/4"
long, overall.
Weight:
4-1/4 lbs. net. 8-1/4 lbs. packed.
Cubage:
0.8 Cu. ft. domestic pack.
DESCRIPTION
The M5700 Program Amplifier is completely
transistorized, and is designed for use as a
line or isolation amplifier in broadcasting
and recording applications. Special tech-
. niques have been employed to obtain low
noise, low distortion, and good temperature
stability.
The amplifier is used with the M6031 Mount-
ing Tray which carries a mating receptacle
and is supplied with mounting hardware. Up
to seven trays may be installed on the
M6029 Shelf Assembly, which mounts in a
standard - Gates rack cabinet, and occupies
3-1/2" of panel space. A keying pin is pro -
0.8
0.6
OA
0.2
o
DB 0
—1
—2
--43
5
vided with the mounting tray to prevent ac.-
cidental interchange of non- similar plug - In
units in the system.
The interstage level control is located on
the front panel of the M5700B model. The
output transformer and receptacle are at-
tached to the frame, and all other compo-
nents are mounted on the printed wiring
boards.
Typical frequency response and distortion
curves are shown in Fig. 2. These meas-
urements were taken with all transistors se-
lected at random.
\.,...,_
TYPICAL TOTAL HARMONIC DISTORTION AT + 24 D8Id OUTPUT
.........
TYPICAL
1
FREQUENCY
RESPONSE
1 i 11 1
150.4x IN, 600.n. 0uT
I r
—,
10 20 50 100 200 500 IKC 2 KC 5KC
101(C 20/(C 50
813 6380 001
KC
Fig. 2 - Response and Distortion.

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2
INSTALLATION
OMOUNTING TRAY AND SHELF ASSEMBLY
Mounting holes have been spaced in the
shelf assembly to allow it to be completely
filled with trays of any one type for the Gates
transistorized units. It is possible, where
maximum use of shelf space is not required,
to mix trays of different sizes. Thus a pro-
gram amplifier and preamplifier could be
placed at the left and a power supply at the
extreme right. Proceed as follows:
1. Locate the first tray at the extreme left
or right of the shelf assembly, with the re-
ceptacle at the rear. The countersunk holes
of the tray will fit into the matching holes in
the shelf, when properly located. Leave a
1/16" space between trays.
2. Secure the tray to the shelf with the two
*4-40 x 1/4" flat head screws with the two
#6 internal- external shakeproof washers un-
e der two # 4 hex nuts.
GUI DE BAR
lir
1313 6350 001
Fig. 3 - Shelf Assembly With Guide Bar
3. Determine whether or not the guide bar,
shown in Fig. 3, will be required. The pur-
pose of this bar is to prevent possible dam-
age to the mating connectors when upward
pressure is inadvertently applied to the am-
plifier during withdrawal. The bar will be
required only where no other protecting ob-
struction is present in the rack, or where the
shelf is used at a location such as a work
bench.
It will not be required where another M6029
. Shelf Assembly is mounted directly above,
or where overhead equipment interferes with •D
mounting of the shelf due to the presence
of the bar. The mounting screws are locat-
ed so that they may be removed from within
the shelf.
4. Mount the shelf in the rack using hard-
ware supplied with the rack. The two end
strips mount underthe screw heads, and are
to be flush with the drop panel.
INPUT AND OUTPUT TRANSFORMERS
The input transformer is factory connected
for 150 ohms primary impedance, as shown
on the schematic diagram and on Fig. 4.
If a terminated input is desired, a 150 ohm
resistor should be connected to terminals
9 and 10 on the amplifier mounting tray,
since the amplifier input is unterminated.
•00FA
ORR
TUT
NIT
SLUE
RED
813 1371 001
Fig. 4 - Input Transformer Connections
Refer to Fig. 4 for connection to 600 ohms
impedance. If a terminated input is requir-
ed, connect a 620 ohm resistor across term-
inals 9 and 10 on the amplifier mounting
tray.
If 6db more gain is desired in some appli-
cations, the input terminating resistor may
be deleted. In this case, however, the
system component preceeding the amplifier
will not be properly terminated.
The output transformer is factory connected
o

e
e
e

3
for 600 ohms secondary impedance. To re-
. connect for 150 ohms refer to the schematic
•
illidiagram. Remove the green/white and black
Wwires from terminal # 7. Connect the black
wire to terminal # 5 and the green/white wire
to terminal # 6.
I
EXTERNAL CONNECTIONS
External connections are made to the mount-
ing tray receptacle as follows:
Circuit Terminals
External Control ( Optional)
+30 V.
Circuit Ground
Output Connections
Output Center- Tap ( 600 ohms)
Input Connections
Input Center- Rap
-30 V.
Chasis Ground
No Connection
1,2,3
4
4
5,6
7
9,10
11
12
13
8,14,15,16
Jumper together all # 13 terminals on the
shelf, whether program amplifiers or other
types, and connect to the rack ground bus.
Connection from rack ground to the circuit
ground in the program amplifier ( B+) should
be made at the amplifier ( not at the power
supply). Make a connection from the rack
ground bus to each amplifier terminal # 14,
SEPARATELY, with at least 18 guage wire.
These circuit grounds must be carried sepa-
rately to prevent the possibility of interac-
tion ( due to mixing of return currents in a
common wire). Where other types of amp-
lifiers are mounted on the same shelf, con-
sult their respective Instruction Book for
grounding information. Where many ampli-
fiers and power supplies are mounted in a
rack, it is preferable to run a vertical rack
ground bus- bar, to pick up grounds at each
shelf.
Run the D. C. supply leads, output pair,
and chassis and circuit ground leads along
the rear edge of the shelf. The D.C. supply
leads should be at least 18 gauge, and must
be run SEPARATELY from each program amp-
lifier to its respective power supply, to pre-
vent the possibility of common coupling in
the power wiring. See the power supply In-
struction Book for further information.
Run input pairs and external control leads
along the shelf brace, above the receptacles.
EXTERNAL VOLUME CONTROL
Reference to the schematic diagram will in-
dicate that the program amplifier is wired to
accommodate an external volume control.
This feature makes it possible to locate the
volume control on an adjacent rack panel,
or on a console control panel , when the amp-
lifier is mounted internally. The internal
control, R30, must be disconnected when
the amplifier is to be used , in this way. The
(R30) control may be ordered as part number
550 0218 000.
THEORY OF OPERATION
For the purpose of explanation, the program
amplifier can be considered to be made up
of two parts: the preamplifier, and the high
level amplifier.
THE PREAMPLIFIER
The four stage preamplifier has a transform-
er coupled input and emitter follower out-
put, with direct càupling utilized between
Q1 and Q2, and between Q3 and 04. Q1
and Q2 transistors are low noise types de-
signed for use in critical low noise appli-
cations.
Biasing is accomplished by a combination
of voltage divider and emitter resistance, as
with R2, R3, and R5. This method of bias-
ing also insures a high degree of tempera-
ture stability. Signal degeneration is pro-
vided for Q1 by RS, and for Q3 by R17. A
loop feedback network connects from Q3,
thru R7 and C5, to Q1 • The large amount of
feedback and degeneration obtained by these

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