Transistor T7112

I was given a box of these devices, in TO-66 package.  The markings are:

Line 1: RTR (Presume Brand)

Line 2 0240 (Presume Date Code)

Line 3 T7112 (Note the "T" is stylised).

The case appears to be aluminium by the feel of it.

Attempts to measure the characteristics have failed, and I find it hard to believe they are all faulty.

If anyone can help me to identify these devices I would appreciate it.  Also I would be happy to make some available to other members if they needed them as replacements.

Cheers,

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Those parts could possibly be thyristors for horizontal deflection in colour tv receivers from the early 70's. That deflection circuitry contains two thyristors, one of them is conducting during the forward scanning and the other is conducting during the retrace (flyback) period. In english language, those are usually mentioned as the "Trace" and "Retrace" thyristors (in german, they are known as "Hinlauf" and "Rücklauf").

RTR on this part could very possibly be a short for "Retrace". Also, TO-66 was the common casing for early such thyristors before the manufacturers changed to TO-220.

The thyristor based horizontal deflection was initially designed and patented by RCA, and soon became used by several manufacturers (usually, but not always, together with RCA's thin-neck CRTs). Among manufacturers who used that circuitry in televisions that were common in my areas in northern Europe, for instance Blaupunkt, Grundig, Salora, ASA, Körting, Sharp may be mentioned.

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Hi Christopher.

The stylised T suggests a manufacturer symbol/logo, so I would guess that the manufacturer was possibly the Transitron Electronic Corporation. You can find mention of Transitron on the internet as it was one of the early semiconductor companies along the famous Route 128 in Massachusetts. And perhaps 7112 is the possible date code?

Only suggestions, but perhaps useful for further leads.

Kind regards, Stan

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Hello,

According to a TI cross reference a RTR0240 can be replaced by a TIC106D. A GE cross reference mentions a C122C as replacement. Both are SCR's but both are TO-220.

Regards D. Consales

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