Miniature relays

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In the 1970s, Tek produced their own miniature relays in-house that were used in some 7000-series plug-ins such as the 7A11, 7A12, 7A13, 7A14, and other equipment. These relays have a tendency to fail and working ones have become very rare. Some of these relays have symmetrical socket layouts so that they can be installed in both possible 180° rotated positions.

Interestingly, Tek appears to have manufactured replacements based on commercial relays in TO-5 metal can cases soldered to small carrier boards with pins matching the Tek sockets.

Possible repair strategies include "micro-surgery" (Ref.1), installing modern miniature gold-contact relays on top of the cut-off base or, if energizing the coil mechanically operates the relay, using a signal source to cycle the relay for a period of time.

Relays of the 148-0034-00 family have contacts with 100mil (2.54mm) pitch; the housings are 16.0 x 8.3 x 15 mm (width x depths x height).

Tek P/N Contacts Coil Used in Replacement Note
108-0599-00 SPST (reed) 7T11: A3K31,A3K32,A3K70,A3K71,A3K80
148-0034-00 DPDT 15 V 600 Ω 7A11: K401,K403,K405,K407,K411,K413,K415,K417,K431
7A13: K47,K48,K480,K490
7A14: K50,K62,K330
7B70, 7B71: K6,K44,K48,K138,K780
7904(A) Opt. 2: K802,K805,K812,K815
AXICOM V23079-D2003-B301 (Ref. 2)
Omron G6N, G6S
148-0034-01 DPDT 15 V 600 Ω 7A12: K7,K12,K15,K18
485: K879,K1242
same pinout as 148-0034-00 but longer leads bent outwards
148-0034-02 DPDT 15 V 600 Ω 7A12: K7 for B020000 up same pinout as 148-0034-00 but longer leads bent outwards
148-0034-03 DPDT 15 V 600 Ω 7A11 B100000+: K401,K403,K405,K407,K411,K413,K415,K417,K431 AXICOM V23079-D2003-B301 (Ref. 2)
148-0035-00 SPDT 15 V 600 Ω 7A13: K60,K61
7A14: K51,K52,K53,K54,K155,K160,K180,K235,K280
7B70, 7B71: K3
Same pinout and coil data as 148-0050-00
148-0043-00 DPDT 24 V 1325 Ω
148-0043-01 DPDT 24 V 1325 Ω
148-0044-00 DPDT 12 V 425 Ω
148-0050-00 SPDT 15 V 600 Ω 7A13: K10,K30 7A13 manual erroneously calls them 12V DC relays. Print on relay identifies them as polarized, but they are not.
148-0054-00 SPDT+SPST 15 V 600 Ω 7A13: K7,K27
148-0055-00 SPDT+SPST 15 V 600 Ω 7A13: K6,K26
148-0058-00 4 V 130 Ω 7A11 Probe: K55,K59
148-0059-00 DPDT 9.5 V 115 Ω
148-0063-00 DPDT 15 V 600 Ω 7A12: K5 Internally connected. Labled "Alt throw relay" in 7A12 manual.
148-0076-00 SPST (reed) 7L12: K1470
148-0080-00 DPDT 5 V at 65 Ω
148-0087-00 SPDT 90 mW 7L12: K300,K353,K356,K1200
148-0088-00 DPDT 15 V 1 kΩ 7L12: K281,K354,K355,K357,K1130,K1400,K1450 same pinout as 148-0034-00. 7L12 manual claims "120 mW", but print on relay (and measurement) says 15V 1000Ω which is 225 mW.
148-0107-03 SPDT TO5 replacement
148-0107-04 DPDT TO5 replacement for 148-0054-00 (7A13: K7,K27)
148-0140-00 Actuator 2400 series

to be expanded


  1. Repairing 7A13 relays @ PA4TIM (how to take relays apart, inside photos)
  2. 7A11 repair report at
  3. Tek 7A13 broken relays @ IK1ZYW Labs
  4. "... used a function generator to actuate it for a few hours which restored proper operation."


Other custom relays in Tek equipment

  • 7A29 input protection relay