My Telefunken Collection

STT 1

Device Type

Analog Tuner with Digital Frequency Display

Start of Sale

1980

General Description

The STT 1 is the 19-inch rackmount version of the CT 20 tuner. This tuner bears a lot in common with its 'smaller cousin' CT 10 - the same tuner board, already known from previous season's tuner TT 350, the same slim-line housing and most knobs have the same position. The only difference is the digital frequency display module:

The module is the same as used e.g. in the TRX 3000. The chip used for the digital clock is not present in the STT 1.

Features

Variable Muting Level, Automatic Fine Tuning, Exact Tuning Indicator

Connectors

FM Antenna (symmetric + coaxial), AM Antenna, AF Output (both DIN an Cinch)

Technical Data

(taken from the service manual)

FM Receiver Section

Wave Range: FM = 87.6 ... 108 MHz

Circuits: 11, 4 tunable

Sensitivity: 0.7 µV at 60 Ohms

1.4 µV at 240 Ohms

Intermediate Frequency: 10.7 MHz

IF Bandwidth: 170 kHz

Selection: >70 dB at ±300 kHz at antenna

Distortion Factor: <0.5% Mono/<0.6% Stereo

(1 kHz, 40 kHz modulation)

Range of Strength Display: 1 µV-1 mV

AM Receiver Section

Wave Range: MW = 518 ... 1610 kHz

(579-185 m)

LW = 148 ... 325 kHz

(2027-937m)

Circuits: 5, 2 tunable

Intermediate Frequency: 460 kHz

IF Bandwidth: 4.5 kHz

General

Semiconductors: 16 Integrated Circuits

21 Transistors

28 Diodes

12 LEDs

Mains Voltage: 220/110 Volts

Fuses: Mains 220 V = 1 x T 125 mA

110 V = 1 x T 125 mA

Secondary 2 x T 315 mA, 1 x T 1 A

Dimensions: 482.6 x 80 x 350 mm

Wright: 6.1 kg

FM Receiver Section
Wave Range:	FM = 87.6 ... 108 MHz
Circuits:	11, 4 tunable
Sensitivity:	0.7 µV at 60 Ohms
	1.4 µV at 240 Ohms
Intermediate Frequency:	10.7 MHz
IF Bandwidth:	170 kHz
Selection:	>70 dB at ±300 kHz at antenna
Distortion Factor:	<0.5% Mono/<0.6% Stereo
	(1 kHz, 40 kHz modulation)
Range of Strength Display:	1 µV-1 mV
AM Receiver Section
Wave Range:	MW = 518 ... 1610 kHz
	(579-185 m)
	LW = 148 ... 325 kHz
	(2027-937m)
Circuits:	5, 2 tunable
Intermediate Frequency:	460 kHz
IF Bandwidth:	4.5 kHz
General
Semiconductors:	16 Integrated Circuits
	21 Transistors
	28 Diodes
	12 LEDs
Mains Voltage:	220/110 Volts
Fuses:	Mains 220 V = 1 x T 125 mA
	110 V = 1 x T 125 mA
	Secondary 2 x T 315 mA, 1 x T 1 A
Dimensions:	482.6 x 80 x 350 mm
Wright:	6.1 kg

Common Failures

The STT 1 suffers from the same, simple failure as may other Telefunken devices in that era: a broken mains switch! Symptoms are that the device cannot be turned on or off any more, or a power switch button that doesn't move at all. The problem is the the 'ball pen' mechanics consist of a piece of metal moving in a plastic bearing, and the plastic wears out over time. Replacing the switch is not that a problem, given you can get one that fits precisely - you need a variant that has both pins on the underside (for soldering into the PCB) and soldering contacts on the upper side (for connecting the power cord).

Spare Part Numbers

(taken from the service manual)

Cabinet Parts

Position Order No. Description

501 309 796 047 cabinet, brown

501a 309 796 049 cabinet, champagne

502 309 833 576 front mask, brown (STT 1)

502a 309 833 603 front mask, champagne (STT 1)

309 833 604 front mask, brown (CT 20)

309 833 605 front mask, champagne (CT 20)

503 309 863 989 frame cassis

504 309 833 577 cover for indicator

505 309 833 578 cover for counter

506 309 833 579 counter mask

508 309 921 921 mains switch rod with button

Electrical Parts

Position Order No. Description

BS 5108 349 362 015 AM-FM-AF-O/P and range rotary switch module

BS 5507 309 369 960 power supply unit for frquency counter

BS 5533 309 310 136 mains transformer with fuse board

BS 5606 349 350 925 FM mixing unit with AM tuning capacitor

BS 5707 349 395 989 frequency counter

BS 5730 349 395 022 LED indicator (field strength)

BS 5769 309 369 977 impedance transformer for freq. counter

BS 5770 309 362 012 switch board (type of operation)

AM-FM Switch Module

Position Order No. Description

BS 5108 349 362 015 AM-FM-AF-O/P and range rotary switch module

BU 101/S 101 309 670 923 AM antenna socket with switch

BU 102 309 670 927 combined antenna socket

BU 103 309 672 801 DIN socket, 5 contacts

BU 104/105 309 679 503 Cinch socket

C 113 309 450 605 disc trimmer N 750 10/40/250 V

C 121 339 582 048 Al-electr. cap. 10 µF/10 V

C 127 309 410 641 Al-electr. cap. 4.7 µF/25 V

C 136/165/184 309 413 482 Al-electr. cap. 100 µF/25 V

C 138/146 309 411 673 Al-electr. cap. 22 µF/10 V

C 141/150/161/ 309 410 634 Al-electr. cap. 4.7 µF/35 V

179

C 152/162 309 410 655 Al-electr. cap. 2.2 µF/25 V

C 153 309 412 645 Al-electr. cap. 47 µF/25 V

C 177 309 414 737 Al-electr. cap. 2200 µF/40 V

C 182/183 309 410 688 Al-electr. cap. 1 µF/25 V

D 104/105/106/ 309 325 027 diode 1 N 4148

108/109/110

FI 101 309 103 952 ceramic filter 10.7 MHz

FI 102 309 111 802 band filter

FI 103 309 103 953 ceramic resonator 460 kHz

FI 104 309 220 031 IF filter coil

FI 105/106 309 103 948 ceramic filter 19 kHz/38 kHz

FU 101 309 627 901 fuse T 315 mA

GR 101 309 320 602 rectifier B 30 C 350/250 KP

IC 101 309 368 133 IC TDA 1046

IC 102 309 368 094 IC CA 3089 E

IC 103 309 368 173 IC TCA 4500 A

IC 104 309 368 130 IC UA 78 GU 1 C

L 101 309 259 919 choke

L 102 309 309 950 antenna transformer

L 103 309 250 930 RF choke 2200 µH

L 104 309 207 922 pre-circuit coil MW

L 105 309 208 911 pre-circuit coil LW

L 106 309 259 934 RF choke

L 107/108 309 218 922 oscillator coil LW

L 111 309 220 083 filter coil 18 MHz

L 112 309 220 046 filter coil 10.7 MHz

R 157 309 500 071 variable resistor 5 K/1/0.15 W

R 166 309 509 401 variable resistor 10 K/1/0.07 W

S 104 309 639 003 rotary switch, 6 positions

T 101 309 001 238 transistor BF 441

T 102/103/107/ 309 001 248 transistor BC 308 B

109

T 104 309 001 227 transistor BF 256 B

T 105/106/110 309 001 949 transistor BC 238 B

T 108/111/112 309 001 241 transistor BC 238 C

520 309 689 904 IC socket, 16 contacts

Power Supply Unit

Position Order No. Description

BS 5507 309 369 960 power supply unit for frquency counter

C 517 309 414 785 Al-electr. cap. 2200 µF/16 V

C 518 309 414 770 Al-electr. cap. 470 µF/40 V

C 520 309 414 729 Al-electr. cap. 1000 µF/40 V

C 521 309 413 468 Al-electr. cap. 100 µF/16 V

D 515-518 309 325 953 diode 1 N 4003

D 522 309 325 634 diode BZY 85 C 16

FU 515 309 627 919 fuse T 1 A

FU 516 309 627 901 fuse T 315 mA

IC 515/516 309 368 130 IC UA 78 GU 1 C

R 517 309 504 805 variable resistor 500/1/0.15 W

FM Mixing Unit

Position Order No. Description

BS 5606 349 350 925 FM mixing unit with AM tuning capacitor

C 105/116/122 309 400 967 tuning capacitor

C 625 309 461 703 Ta-electr. cap. 22 µF/6.3 V

D 601 309 327 956 diode SMV 709

D 602 309 325 027 diode 1 N 4148

FI 601 309 220 013 IF filter

L 601 309 209 930 FM antenna coil

L 602 309 209 931 pre-circuit coil

L 603 309 219 935 oscillator coil

L 604 309 249 171 intermediate circuit coil

L 605 309 250 943 RF choke

T 601 309 005 007 transistor 2 SK 55 D

T 602/603 309 001 933 transistor BF 241

Frequency Counter

Position Order No. Description

BS 5707 349 395 989 frequency counter

C 701 309 461 703 Ta-electr. cap. 22 µF/6.3 V

C 722 309 450 806 disc trimmer N 750 6/25/250 V

C 728 309 410 698 Ta-electr. cap. 4.7 µF/35 V

C 733 309 413 508 Ta-electr. cap. 100 µF/10 V

D 700-705 309 325 927 diode 1 N 4148

D 706/707 309 325 064 diode 1 N 4848

D 708 309 325 965 diode BZY 85 C 5 V 6

D 709 309 327 037 diode 6.2 V

IC 700 309 368 112 IC SN 74 LS 112 N

IC 701/702 309 368 207 IC SN 74 LS 90 N

IC 703/705 309 368 208 IC SN 74 LS 74 N

IC 704 309 368 115 IC TL 7404 N

IC 707 309 368 117 IC DFU 101

IC 708 309 368 176 IC IC SN 74 S 04 spec.

L 701 309 259 919 choke

L 703 309 250 935 RF choke

L 704 309 259 933 RF choke

L 705/706 309 250 934 RF choke

LA 700/701 309 621 968 bulb 4.3 V/100 mA/0.43 W

QU 700 309 335 992 crystal 5.12 MHz

R 740 309 504 995 variable resistor 50 KOhm

T 700 309 001 933 transistor BF 241 P

T 701 309 001 108 transistor BC 307 B

T 702 309 001 120 transistor BC 213

V 700 309 395 962 fluorescent display

LED Indicator

Position Order No. Description

BS 5730 349 395 022 LED indicator (field strength)

522 309 900 292 diode holder, 12-fold

D 701-710 309 327 053 LED CQY 85 red

D 711 309 327 022 LED FLV 110 red

IC 701 309 368 231 IC U 254 B

IC 702 309 368 230 IC U 244 B

Impedance Transformer

Position Order No. Description

BS 5769 309 369 977 impedance transformer for freq. counter

L 705 309 259 919 choke

T 712 309 001 933 transistor BF 241 P

T 713/714 309 001 949 transistor BC 238 B

Mechanical Parts

525 309 926 808 tension roller for cord

526 309 981 802 spring for tension roller

527 309 926 983 cord disc

528 309 928 904 clutch

529 309 870 925 dial cord

530 309 943 020 tuning shaft

531 309 927 909 flywheel

532 309 900 295 diode holder

533 309 653 501 fuse holder

534 309 928 904 clutch for shaft

535 309 943 022 shaft for range

		Cabinet Parts
Position	Order No.	Description
501	309 796 047	cabinet, brown
501a	309 796 049	cabinet, champagne
502	309 833 576	front mask, brown (STT 1)
502a	309 833 603	front mask, champagne (STT 1)
	309 833 604	front mask, brown (CT 20)
	309 833 605	front mask, champagne (CT 20)
503	309 863 989	frame cassis
504	309 833 577	cover for indicator
505	309 833 578	cover for counter
506	309 833 579	counter mask
508	309 921 921	mains switch rod with button
		Electrical Parts
Position	Order No.	Description
BS 5108	349 362 015	AM-FM-AF-O/P and range rotary switch module
BS 5507	309 369 960	power supply unit for frquency counter
BS 5533	309 310 136	mains transformer with fuse board
BS 5606	349 350 925	FM mixing unit with AM tuning capacitor
BS 5707	349 395 989	frequency counter
BS 5730	349 395 022	LED indicator (field strength)
BS 5769	309 369 977	impedance transformer for freq. counter
BS 5770	309 362 012	switch board (type of operation)
		AM-FM Switch Module
Position	Order No.	Description
BS 5108	349 362 015	AM-FM-AF-O/P and range rotary switch module
BU 101/S 101	309 670 923	AM antenna socket with switch
BU 102	309 670 927	combined antenna socket
BU 103	309 672 801	DIN socket, 5 contacts
BU 104/105	309 679 503	Cinch socket
C 113	309 450 605	disc trimmer N 750 10/40/250 V
C 121	339 582 048	Al-electr. cap. 10 µF/10 V
C 127	309 410 641	Al-electr. cap. 4.7 µF/25 V
C 136/165/184	309 413 482	Al-electr. cap. 100 µF/25 V
C 138/146	309 411 673	Al-electr. cap. 22 µF/10 V
C 141/150/161/	309 410 634	Al-electr. cap. 4.7 µF/35 V
179
C 152/162	309 410 655	Al-electr. cap. 2.2 µF/25 V
C 153	309 412 645	Al-electr. cap. 47 µF/25 V
C 177	309 414 737	Al-electr. cap. 2200 µF/40 V
C 182/183	309 410 688	Al-electr. cap. 1 µF/25 V
D 104/105/106/	309 325 027	diode 1 N 4148
108/109/110
FI 101	309 103 952	ceramic filter 10.7 MHz
FI 102	309 111 802	band filter
FI 103	309 103 953	ceramic resonator 460 kHz
FI 104	309 220 031	IF filter coil
FI 105/106	309 103 948	ceramic filter 19 kHz/38 kHz
FU 101	309 627 901	fuse T 315 mA
GR 101	309 320 602	rectifier B 30 C 350/250 KP
IC 101	309 368 133	IC TDA 1046
IC 102	309 368 094	IC CA 3089 E
IC 103	309 368 173	IC TCA 4500 A
IC 104	309 368 130	IC UA 78 GU 1 C
L 101	309 259 919	choke
L 102	309 309 950	antenna transformer
L 103	309 250 930	RF choke 2200 µH
L 104	309 207 922	pre-circuit coil MW
L 105	309 208 911	pre-circuit coil LW
L 106	309 259 934	RF choke
L 107/108	309 218 922	oscillator coil LW
L 111	309 220 083	filter coil 18 MHz
L 112	309 220 046	filter coil 10.7 MHz
R 157	309 500 071	variable resistor 5 K/1/0.15 W
R 166	309 509 401	variable resistor 10 K/1/0.07 W
S 104	309 639 003	rotary switch, 6 positions
T 101	309 001 238	transistor BF 441
T 102/103/107/	309 001 248	transistor BC 308 B
109
T 104	309 001 227	transistor BF 256 B
T 105/106/110	309 001 949	transistor BC 238 B
T 108/111/112	309 001 241	transistor BC 238 C
520	309 689 904	IC socket, 16 contacts
		Power Supply Unit
Position	Order No.	Description
BS 5507	309 369 960	power supply unit for frquency counter
C 517	309 414 785	Al-electr. cap. 2200 µF/16 V
C 518	309 414 770	Al-electr. cap. 470 µF/40 V
C 520	309 414 729	Al-electr. cap. 1000 µF/40 V
C 521	309 413 468	Al-electr. cap. 100 µF/16 V
D 515-518	309 325 953	diode 1 N 4003
D 522	309 325 634	diode BZY 85 C 16
FU 515	309 627 919	fuse T 1 A
FU 516	309 627 901	fuse T 315 mA
IC 515/516	309 368 130	IC UA 78 GU 1 C
R 517	309 504 805	variable resistor 500/1/0.15 W
		FM Mixing Unit
Position	Order No.	Description
BS 5606	349 350 925	FM mixing unit with AM tuning capacitor
C 105/116/122	309 400 967	tuning capacitor
C 625	309 461 703	Ta-electr. cap. 22 µF/6.3 V
D 601	309 327 956	diode SMV 709
D 602	309 325 027	diode 1 N 4148
FI 601	309 220 013	IF filter
L 601	309 209 930	FM antenna coil
L 602	309 209 931	pre-circuit coil
L 603	309 219 935	oscillator coil
L 604	309 249 171	intermediate circuit coil
L 605	309 250 943	RF choke
T 601	309 005 007	transistor 2 SK 55 D
T 602/603	309 001 933	transistor BF 241
		Frequency Counter
Position	Order No.	Description
BS 5707	349 395 989	frequency counter
C 701	309 461 703	Ta-electr. cap. 22 µF/6.3 V
C 722	309 450 806	disc trimmer N 750 6/25/250 V
C 728	309 410 698	Ta-electr. cap. 4.7 µF/35 V
C 733	309 413 508	Ta-electr. cap. 100 µF/10 V
D 700-705	309 325 927	diode 1 N 4148
D 706/707	309 325 064	diode 1 N 4848
D 708	309 325 965	diode BZY 85 C 5 V 6
D 709	309 327 037	diode 6.2 V
IC 700	309 368 112	IC SN 74 LS 112 N
IC 701/702	309 368 207	IC SN 74 LS 90 N
IC 703/705	309 368 208	IC SN 74 LS 74 N
IC 704	309 368 115	IC TL 7404 N
IC 707	309 368 117	IC DFU 101
IC 708	309 368 176	IC IC SN 74 S 04 spec.
L 701	309 259 919	choke
L 703	309 250 935	RF choke
L 704	309 259 933	RF choke
L 705/706	309 250 934	RF choke
LA 700/701	309 621 968	bulb 4.3 V/100 mA/0.43 W
QU 700	309 335 992	crystal 5.12 MHz
R 740	309 504 995	variable resistor 50 KOhm
T 700	309 001 933	transistor BF 241 P
T 701	309 001 108	transistor BC 307 B
T 702	309 001 120	transistor BC 213
V 700	309 395 962	fluorescent display
		LED Indicator
Position	Order No.	Description
BS 5730	349 395 022	LED indicator (field strength)
522	309 900 292	diode holder, 12-fold
D 701-710	309 327 053	LED CQY 85 red
D 711	309 327 022	LED FLV 110 red
IC 701	309 368 231	IC U 254 B
IC 702	309 368 230	IC U 244 B
		Impedance Transformer
Position	Order No.	Description
BS 5769	309 369 977	impedance transformer for freq. counter
L 705	309 259 919	choke
T 712	309 001 933	transistor BF 241 P
T 713/714	309 001 949	transistor BC 238 B
		Mechanical Parts
525	309 926 808	tension roller for cord
526	309 981 802	spring for tension roller
527	309 926 983	cord disc
528	309 928 904	clutch
529	309 870 925	dial cord
530	309 943 020	tuning shaft
531	309 927 909	flywheel
532	309 900 295	diode holder
533	309 653 501	fuse holder
534	309 928 904	clutch for shaft
535	309 943 022	shaft for range

Available Documents

Service Manual

Back to List