The IC3600 and IC3606 families belong to GE Speedtronic Mark I and Mark II — the oldest turbine control systems still running in the field. These are analog and discrete-logic cards, built long before microprocessor control reached the Speedtronic line.
If you run one of these, read this part
Mark I and Mark II parts are genuinely scarce. Not "long lead time" scarce — scarce. These systems are decades old, the card population shrinks every year, and there is no manufacturer to fall back on.
The blunt advice: an on-shelf spare set is not a luxury for these panels. It is the difference between a bad week and a bad quarter. If you are still running a Mark I or Mark II and you have no spares, you are one card failure away from a problem that money alone may not solve quickly.
This applies to the service items too, not just the control cards. The card extenders — which let you plug a card out of the rack and probe it live — were never bought in the quantities control cards were. A site might have owned one for an entire panel, or none. Fifty years later the surviving population is small. If you maintain a Mark I or Mark II and you do not own an extender, you are working with one hand tied.
What the IC3600 and IC3606 families cover
Between them these prefixes span a wide range of functions, including thermocouple amplifier cards, temperature control cards, peaking operation cards, vibration detector, calibrator and alarm cards, speed and high-speed sensor cards, voltage regulator cards, annunciator cards, binary counters, logic and shift-register cards, and time delay cards. The IC3606 numbers additionally cover isolated inputs, annunciator master cards, card extenders and thermo process module switches.
Both prefixes belong to the same generation and are frequently cross-referenced. Do not assume a prefix difference means a different generation. Quote the full number.
Protection cards deserve extra care
Cards in the protection path — over-temperature, overspeed, vibration alarm — exist to take the machine offline before something expensive happens. A degraded protection card may work perfectly until the day it was supposed to act, and you will not know. Match the revision, and do not run these paths without a spare.
Finding the number
On cards this old the part number is often stamped on the card edge or the ejector tab rather than silkscreened across the face. Look there first. If the marking is unreadable, photograph the card — component layout and connector arrangement are usually enough for us to identify the family.
An IC3600 number like IC3600SOTE1C1B splits into the family prefix, the functional acronym (SOTE), and the trailing group and revision digits (1C1B).
Requesting a quote
Send us the full part number as printed on the card, whether the panel is Mark I or Mark II, the rack type, whether the card is in service or a shelf spare, and — importantly for this generation — whether you can accept an alternate revision. For IC3600 parts that is frequently the difference between finding one and not. Tell us if you want us to watch the market for more. We reply within 24 hours, ship worldwide DDP, and accept purchase orders.








































