DavidJRichards/Aviation_DriftAngle_GroundSpeed_Indicator

Decca 5841-99-622-9212 Type 9308WN28WM

Drift Angle & Ground Speed Indicator

Decca 5841-99-622-9212 Type 9308WN28WM

Wiring Images Documents Videotest

schematics servomotortest

PLA Connector

Details as seen from rear when unit level, connector is skewed from standard.

Outer row	Wire	Term		Middle row	Wire	Term
A	red-59	rly2:coil a		U	pink-95	Pot1
B	pink-62	rly7:Com		V	pink-87	18 f-flag
C	black-98	tran9:		W	red-91	rly6:coil b
D	pink-120	40-fp112		X	pink-74	S-black7
E	n/c	-		Y	pink-80	S-red9
F	pink-70	31 Test sw1		Z	red-90	rly6:coil b
G	pink-63	rly5:NC		a	pink-58	41 unknown
H	pink-44	rv1		b	n/c	-
J	pink-45	rv2, C2, C3		c	pink-64	17 Mem. sw
K	pink-81	14 unknown		d	n/c	-
L	pink-73	32 Test sw2		e	n/c	-
M	n/c	-
N	n/c	-		Inner row	Wire	Term
P	n/c	-		f	pink-119	39-fp111
R	red-60	DC in red		g	black-93	chassis
S	pink-121	113-fp		h	black-84	78,79,black
T	pink-61	rly7:Com		j	pink-122	38-fp114

Notes:

• B&T connected AC 26v 400Hz
• g chassis connected, Common AC
• W&Z connected Return DC -ve
• R&A connected DC +26V
• R main DC +ve feed to amp
• C, W, g, h, common
• Front panel bulbs all open circuit!
• Signal input pins ?
• ground 'V' to clear F-flag
• no servomotor amplifiers in unit
• c Mem switch to chassis

X1 servomotor, Ground speed

• reference: Qqad AC & Chassis
• control: 'X' input and Switched DC

X2 servomotor, Drift angle

• reference: 'K' input & Chassis
• control: 'Y' input & Switched DC

Error amplifier

• input from error potentiometer & tacho generator
• output to X4 resolver

Back panel

note: link 16 to 19 (pink-76) to 'PLA' c' link 6 to 7(bare wire) link 15 to 20(pink-75)

3
4
6 & 7	black-52,C10-?,C11-?	'h'
8	black-98,black-22,C8a	transformer 9
9	pink-21,pink-43,C8b	transformer10
10	pink-44,pink-46,C10	'H', RV1-1
11	pink-45,C11	C11b to J
12	X1-black7,pink-74	'X'
13	X2-S-red7207,pink-80	'Y'
14	pink-9159,pink-81	'K'
15	pink-75,S-white3,C2
16	pink-76,pink-77,C?	C2 to pink-75, 'J'
17	pink-65,pink-64	'c' mem switch to chassis
18	pink-97,pink-86	Resolver-S7,Pot2-wiper
19	pink-77,pink-76,C3-?	via C3 to
20	pink-75,yellow-7147,C3	'J' 50 ohms to chassis
E1	black-125,black-93	chassis

Transformer

Pin#		Wire
1		n/c
2	priC	pink-39	pink-38
3		n/c
4	pri1	pink-40	TR2-c
5		n/c
6		n/c
7	pri2	pink-41	TR3-c
8		pink-39	71,red (DC+ve)
9	sec1	black-42	Resolver X4-
10	sec2	pink-43	Resolver X4-S1

No.1 PCB

Term	Wires
71	red-55,red-88	DC
72	black-92	Chassis E2
73	pink-57	TR1 input
74	black-9,black-42	Transformer9
75	black-33,black-96	Pot3
76	pink-54	R7,C to SL201-2
77	pink-31,pink-97	X4-S5,Pot2-wiper
78	S-blue7167,black-85	?
79	black-52,black-84	T6&7 'h'
80	pink-32,pink-95	Pot1 'U'
81	pink-53	R5-1k8,C to SL201-3
82	pink-41	TR2-c,Transformer7
83	pink-40	TR3-cTransformer4
84	pink-28	Resolver X4-R2
85	pink-27	Resolver X4-R1
86	pink-56	R10-10k

## No.2 PCB 

Term	Wires
31	pink-69,pink-70	Test sw1
32	pink-72,pink-73	Test sw2
33	S-green8,S-red/black9
34	S-lime18,S-red/black19
35	X1-blue767,pink-83
36	X1-brown1,pink-82
37	pink-117,pink-121
38	pink-118,pink-122
39	pink-115,pink-119
40	pink-116,pink-120
41	pink-58,pink-124
53	pink-53, R5-1k8
54	pink-54, R7-1k8
55 -	pink-39,pink-123	link-55-56-57 DC
56 -	red-59,red-60	link-55-56-57 DC 'A'
57 -	red-89,red-55	link-55-56-57 DC
58	pink-56,R10-10k
59	pink-57,R21-1K	to Cx - TR1
60	pink-25,R21
61	pink-29,R12-2k2
62	pink-50,R12
63	pink-24,pink-97	R20, resolver X4-S5
64 -	pink-78,pink-79	link-64-65, switched DC
65 -	X2-black17,X1-red5	link-64-65
66	black-94	chassis

Components

Part	Value
R1
R2	27k
R3
R4	470R
R5	1k8
R6	100R
R7	1k8
R8	100R
R9	68k
R10	10k
R11	68k
R12	2k2
R20	68k
R21	1k
RV1	5K
RV2	1K
X5	2k	5%
C1	22uF	35v
C4	22uF	15v
C5	47uF	20v
C6	22uF	15v
C7	22uF	15v
C2	1uF	160V
C3	1uF	160V
C8
C10	11uF	15v
C11	11uF	15v
D1	diode
D2	12v	zener
D3,4,5	diode
TR1	CV7770	TO5, NPN, ebc
TR2,3	2N2405	To39, npn, ebc, 1A
TR4,5	2N3823	to72, n-fet, sdgc
X6	SL201B	Transistor array IC
relay	24V DPCO	820 Ohm

• diode is 7517 | 7537 | 7157 | 7357 | something

RLA Relay

24 Volt, 830 Ohm

Pin	Wire
1	n/c	NC-3
2	red-89	coil-a
3	pink-123	Com-1&8	DC input
4		NO-7	Switched AC
''	orange-11	synchro GEN 26V
''	orange-1	synchro GEN 26V
''	pink-17
5	pink-63	NC-7
6	red-90	coil-b
''	red-91
7	pink-61	Com-4&5	AC input
''	pink-62
8	pink-79	NO-3	Switched DC

X1 Ground Speed Servomotor Tachometer

200:1 gearbox

		Colour	Terminal	Wire
1	Ref	yellow	E2	chassis
3	Ref	white	15	quad AC
2	Con-a	red	65	X1-red5
5	Con-a	red/black	33	link-33
6	Con-b	green	33	link-33
4	Con-b	black	12 'X'	X1-black7
7	Eng	orange	16	Switched AC
10	Eng	grey	E2	chassis
8	Sig	blue	35	X1-blue767
9	Sig	brown	36	X1-brown1

X5 Ground Speed Potentiometer

2k ohms 5%

pin	wire
1	pink-32
2	pink-31
3	black-33

X2 Drift Servo Motor Tachogenerator (blue)

• SM | Y-W 26V| R-R/BK 13V | G-BK 13V
• GEN | O-GY 26V | B-BN 0.285V/1000 RMM

	code	colour	terminal
1	Y	yellow	Ref SM 26V	14 yelow7147
3	W	white	Ref SM 26V	E2 chassis
2	R	red	Con-a SM 13Va	13 'Y'
5	R/BK	red/black	Con-a SM 13Va	link-34
6	G	lime-green	Con-b SM 13Vb	link-34
4	BK	black	Con-b SM 13Vb	64 Switched DC
7	O	orange	Eng GEN 26V	Switched AC
10	GY	grey	Eng GEN 26V	E2 chassis
8	B	blue	Sig GEN RPM	78,79
9	BN	brown	Sig GEN RPM	14 'K'

X4 Drift Resolver Compensating

Name	Wire		tag#
X4-S1	pink-21	transformer #10	9
X4-S3	black-22	transformer #9
X4-S2	pink-23	S2-S4 linked	-
X4-S4	pink-23	S2-S4 linked	-
X4-S5	pink-24	R20	63
X4-S7	pink-25
X4-S6	pink-26	S6-S8 linked	-
X4-S8	pink-26	S6-S8 linked	-
X4-R1	pink-27	to Cx - TR2	85
X4-R3	pink-29	R12	61
X4-R2	pink-28	to Cy - TR3	84
X4-R4	pink-30	RV1-2	direct

Misc Bindings

Terminal	Wire	Function
t113	pink-121	fp
t39,t111	pink-119	fp
t38,t114	pink-122	fp
chassis E1	black-125, black-93
chassis E2	S-grey12, S-white13, S-grey2, S-yellow747
chassis E2	black-92, black-94, black-125
chassis E3	S-black-67, S-black-37	Flag motor?
RV1-1	pink-46
RV1-2	pink-30
RV2-1	pink-47
RV2-1	pink-50
TestSw1	pink-71
TestSw2	pink-68
MomSw1	pink-66
MomSw2	black-68	chassis

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