House Numbers

[url=https://www.datasheetarchive.com/motorola hep cross reference-datasheet.html][You must be registered and logged in to see this link.]
This might help.
 Also look in the Members only area as I posted a lot of cross ref info there in the past.

Take a look here on radio museum, the only difference is that this one uses 2 transistors.
I think using one of transistors may work.

2N457
2N457 Datasheet, Equivalent, Cross Reference Search
Type Designator: 2N457
Material of Transistor: Ge
Polarity: PNP
Maximum Collector Power Dissipation (Pc): 50 W
Maximum Collector-Base Voltage |Vcb|: 60 V
Maximum Collector-Emitter Voltage |Vce|: 60 V
Maximum Emitter-Base Voltage |Veb|: 20 V
Maximum Collector Current |Ic max|: 7 A
Max. Operating Junction Temperature (Tj): 100 °C
Transition Frequency (ft): 0.2 MHz
Forward Current Transfer Ratio (hFE), MIN: 10
Noise Figure, dB: -
Package: TO3

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Or rather than going that route go with this  simple schematic HERE --->  [You must be registered and logged in to see this link.]
Not any more work I would think. Just a suggestion.

Rod, Yes you can.
Google NTE cross reference.
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I wonder if someone out there still has an ECG, RCA, or GE transistor substitution handbook lying around. Reason I ask: I just got in today one of the little EICO 1020 solid state variable power supplies and I am curious about the pass transistor it uses. As some background info, there were at least two versions of this power supply produced. One of them used (2) 2N457 germanium TO-3 power transistors (wired in series with a dual voltage control pot). The other uses a single NPN silicon TO-3 transistor. The second one is the one I have. There is a manual online at BAMA for this version. The part number given in the manual for Q1 is 94059 and that number is also stamped on the actual transistor in the power supply. There is also a redrawn schematic online for the 2N457 version. It is referred to by the author as model "1020B".

My question is: can anyone look up an ECG, RCA, GE or NTE substitute for this house branded transistor number? It would be helpful (and fun) to know what the characteristics of the sub are.  Thanks in advance.

73, Rod  WB6FBF

I just remembered One of my stints was working with a planner-man in our shop. Anything the Government had could be researched down to the nuts and bolts. A lot of it was electronic hardware that was commercial and of course military.

I used to sit and go through parts manuals and microfiche to order anything.
The fische had several sources provided by the Supply system.

Sometimes I would go online to naval supply to see what descriptions and federal stock numbers were. Usually they had several manufacturers produce the same product and that included Solid-state devices, passive devices and how many were available.

If you peruse the Web extensively you can find a wealth of data that most people don't even think about. Also look under N.A.T.O. they are tied into the Federal Stock Number system. I will see if I can dig up some links and post here.

Looks like you can start to borrow into Govt. Supply, However when you download the browser balks because of security issues. And If you want to dig further you have to have two types of permit numbers. Didn't use ta bee that away.

House numbers used to bedevil me too. Sometimes I could guess the chip number from the circuit used. IC handbooks with standard and test circuits could help with identification. Then there were the custom variations of standard ICs. Replacements for these could be a gamble. You couldn't tell what functions you would get until you powered the device up and checked it out. Sometimes enough would work to make the customer happy (TV set for example).

A couple of things I found out is a lot of times transistors and chips did not print the designator on them. Example:
2N2222 became 2222. So of course that probably saved ink & people would think it was a proprietary part number.

I remember Our Cal. Lab had a Sales rep show us a hand held device that would identify I.C.s, it got a few spot on but wouldn't recognize Military types.

Frank,

Most of the time I was able to crack the house numbers (pre-internet) using either an ECG or an RCA SK-line solid-state reference handbook. I found that having several years of the books was essential as it seemed that some part numbers got edit out and others put in. Very helpful in tracking old germanium devices.

Then there was the "H'm how would I design this?" and often derived a device number from what the circuits was supposed to do...
During the 80's-90's there was a series of "generic" circuits published in several 2" thick volumes, often a representative circuit was offered and had, sometimes, the part numbers.

I have also encountered circuits where a Dremmel with a dental burr was used to wipe chips...

IMHO the obliterated numbers were to prevent circuit reverse engineering. More often done by small companies that could not afford to keep patent lawyers on staff...

Or to hide the fact that the circuit is a counterfeit or an off-license copy. Many times the device was potted in hard black epoxy resin...

Lookup, Cordover Modules


As I once worked for a multi-million $ company, I had some leverage calling vendors and also had consultants on the payroll as well as very aggressive purchase order clerk.

With all the help, I got what I wanted...

Chas

The bane of a tech's existence.

This is not a new thing. It dates clear back to the early days of radio.

Several mfgrs. would house number parts with their own numbers.
 This made it difficult to ID what the part number really was to repair the item.
 I believe this was to force the tech to buy the part from the mfgr. at a greatly inflated price, and to keep non-tech folks from attempting repairs.
 They did this on many items. Semis, diodes, tubes, pots, etc.

The truly evil ones would use a chemical to remove the JEDEC number from the semi before installing it in their product, and I have even seen them sand off the part number on IC's!

Then they would mark the board like: U-1, U-2, T-1, TR1, etc.
 Yup trying to force you to send it to them for repairs, is my best guess.

If they used the chemical method, often you could see where the chemical didn't remove the JEDEC number completely, and so you knew what the part really was.
 I remember a repair I did where they had 4-5 identical IC's where they removed the number, but I was able to very faintly see it on the part.
 The parts were something like CD4016 IC's. At the time they cost under $.50 each, but the mfg. wanted $15.00 EACH for them. :evil:
  Needless to say I fixed the unit, and would have never gotten the repair at the price they were asking for the part.

I often found "unmarked"  or non-readable IC's in things like pellet stove controllers too. Of course, this made it non-repairable when the company went out of business, as all parts were NLA.

 There were a few really cool factory techs or parts people out there that would actually tell me what the unmarked or house numbered parts JEDEC number really was. 
 I found the best way was to chat with them a bit and politely ask if they had any info at all they could give me. Once they knew I did know my beans, they would often tell me what I needed, sometimes "unofficially". Wink Wink- Nudge Nudge.

Some of the companies that used non-standard numbering, aka house numbers were Motorola, RCA, Tektronics, Magnavox, Zenith, and many, many others.
 Some would use both JEDEC and house numbers mixed in their products too.

 Some even went so far as to re-number vacuum tubes and semi's with their own numbers on them!
 Now I admit this was often because they matched the tube sections, or had special characteristics in a tube or semi that had to be there for it to work right.
( This special application numbering was very much like Sony's color dot markings on transistors for Beta characteristics where the device they were used in would not work at all if the specs were off.)

 I have some house numbered dual triode tubes in Tektronics packaging, with their own part numbers on the package, NOS. The note on them also says both tubes are matched especially for the application and both must be replaced if the scope amplifier is to properly work accurately.