"MA" transistor markings for ANH Obi Wan Kenobi's Llightsaber

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ATL Kenobi

Sr Member
I've been asked a couple of times to re-post my explanation of the markings on the transistors used as "buttons" on the ANH OWK lightsaber. FWIW- here's my post from April 2006:

As I’ve mentioned, I’m an electrical engineer and I’ve been specifying semiconductors (transistors) since 1980. I became interested in replicating an OWK ANH saber in mid-October of 2005, an exciting time for parts identification. I was intrigued by the revelation that the 2 “control buttons” had been identified as TO-39 cased transistors (TO – transistor outline).

James Kenobi had an interesting RPF post where he showed close ups of the two transistors.

James image.png Pic originally posted by James Kenobi.

He also overlaid, at an angle, the logo for NEC (Nippon Electric Corp). When I first saw that composite, it seemed that NEC was probably the correct manufacturer. However, the more I thought about it, the more questions arose. The first thing I considered was the angled logo. Semiconductor manufactures are very protective of there logos. Their marketing departments go to great lengths to develop an easily recognizable image, that’s then trade marked and copyrighted. See http://www.elnec.com/iclogos_l.php . Also, after researching several new and old transistor databooks, I could not find any NEC manufactured device that began with “MA”, so I decided to rule out NEC.

Looking at the transistor on the left, it does sort of appear that the logo looks like an “N” followed by a subscript “2”. As far as I’ve been able to find out, there’s never been a logo of this style, and none of the known manufacturers that did use a stylized “N”, had a logo that looked like that.

After studying the transistor that’s a little more legible, it seems apparent to me that the right edge is severely damaged and that the markings have been scuffed. Transistors markings of that era were either rubber stamped or screened with ink. Looking closely at the image, it seems as if there’s a streak across the logo (see the blue line on the picture below).

vintage MA909.png

I concluded that the transistor could very likely be a Motorola device. I found a 1969 Motorola databook and, low and behold, there was a whole series of TO-5 cased transistors that start with “MA”. TO-5 and TO-39 are the same case size, but the TO-5 leads are an inch longer. The actual transistor shown here is an MA909. Note the similarity in the fonts. The 552 is a date code, probably signifying the 52nd week of 1965 or possibly 1975. The date code on the originals is completely obliterated.

I can’t adequately explain what many have taken to be a “2” beneath the logo. This seems to appear in both original transistor images. I highly suspect that it’s simply a triangular shaped stamping artifact from a worn stamping mechanism and not relevant to the logo itself. I’m hoping that if more original transistors of the series can be found, one will have a similar defect.

There were many transistors (now obsolete) in that original “MA” series. Their part numbers were:
MA100, MA101,
MA112 through MA117,
MA200 through MA206,
MA286 through MA288,
MA881 through MA889,
MA909, MA910.
Since the numbers on the prop transistors are totally unreadable, any two of the above could have been what was used.

This is the original datasheet:
MA100 data sheet.jpg

-END of original post.-

My "all original" saber has only one vintage "MA" marked transistor. The other one does have the "MA" markings and is a Motorola device, but it's much newer. For my cut-away saber and my Roman's AFBB saber, I just used generic devices.

ATL Kenobi
 

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thd9791

Master Member
RPF PREMIUM MEMBER
Hey thanks for this! That triangular artifact has bothered me for ages...but hearing about how the logos were put on put me slightly at ease haha it's also great to hear all this info form someone in the field.
 

thd9791

Master Member
RPF PREMIUM MEMBER
I'd like to add some photos expressing the awkward inconsistencies of stamping mechanisms back in the day!

The first one has a gap between lines, second a much simpler Motorola logo that could be mistaken for an N or A, Third a blunted, misprinted logo, and fourth a staggered print.


Screen shot 2014-10-17 at 11.34.02 PM.pngScreen shot 2014-10-17 at 11.35.05 PM.pngScreen shot 2014-10-17 at 11.35.30 PM.pngScreen shot 2014-10-17 at 11.37.06 PM.png
 

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spoudastis

Well-Known Member
RPF PREMIUM MEMBER
Great post, seems to me to be pretty definitive. Used this advice to buy by MA's and am very happy with them.
 

ATL Kenobi

Sr Member
thd9791 Thanks for posting the pictures showing the inconsistencies! It's one more piece of the puzzle.... :)

ATL
 

thd9791

Master Member
RPF PREMIUM MEMBER
Absolutely, I was happy to see this myself.

Where are people locating specific vintage electronic components?
 

ATL Kenobi

Sr Member
Of course this was years ago, but the MA909 pictured above I found on eBay after searching daily for months. I believe I searched with the key words TRANSISTOR, GERMANIUM, and MA*. (Not sure you can even use wildcard searches anymore). The other "MA" I found was an MA205 which was basically the same search but through Google. A vendor selling obsolete semiconductors had them.

Good luck on your search!

ATL
 

TheRealMcFly

Sr Member
RPF PREMIUM MEMBER
Sorry to dig up the past on this one but it was the most concise and current discussion thread I could find on these transistors.

Nearly eight years of hunting parts for my own version of this famous hilt and only recently did an Exactra 19 convince me to finally finish. Naturally I went down the rabbit hole that is the search for transistors that matched this new (to me) image.

Nothing yet found quite matches. Yes it it does look like a blotched Motorola "M" logo, but the majority of of the MA markings do not appear like the prop, which has parallel vertical ends. I could not find any, although they do exist on replicas here. Still I could not reconcile the text-line spacing and size of the Motorola logo. There are many theories as to what the mysterious '2' shaped blob might represent but no vintage Motorola transistor that exactly matches this particular detail.

I spent hours searching images of old TO5 and TO39 transistors as many have done before.

One matched. Stay with me here...
image.jpg

These are Solitron brand transistors with a logo of the era, dating to 1975 I believe. Think outside of the box on this with me and imagine that the "N" isn't a 'positive' representation of an M but the remnant of the 'negative' Solitron "S" instead? This provides an explanation for the spacing and the mysterious "2" which could just be a leftover of the box around the S.

Could this brand have produced a "MA" series? Their printing seems to be a bit more ransom-note like and perhaps the original markings from the enlarged reference are not MA at all. It does look like that but maybe other prefixes should not be ruled out.
 

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thd9791

Master Member
RPF PREMIUM MEMBER
Good try bud! I always like seeing new theories, however I don't think this one pans out. The dark area on a Solitron logo doesn't match up with what's on the prop, there would have to be a break on the left side of the "M"

Also, I'm pretty sure they put Amplifiers on the hero, not full sized transistors - you can see the shadows when it falls into his cloak.

I am fully on board with another company though, it would explain the "2" subscript!
 

Halliwax

Legendary Member
RPF PREMIUM MEMBER
this is off topic, but do we know where the original obiwan hero saber is today?
 

Sym-Cha

Master Member
No ... we don't ... neither does anyone currently at Lucasfilm Ltd. ... or so it seems :wacko

Chaim
 

TheRealMcFly

Sr Member
RPF PREMIUM MEMBER
Good try bud! I always like seeing new theories, however I don't think this one pans out. The dark area on a Solitron logo doesn't match up with what's on the prop, there would have to be a break on the left side of the "M"

Also, I'm pretty sure they put Amplifiers on the hero, not full sized transistors - you can see the shadows when it falls into his cloak.

I am fully on board with another company though, it would explain the "2" subscript!
What are these "amplifiers" and how could you see anything clearly from that scene in the movie?

This was a quick and dirty photoshop but all I did was take one of these Solitron transistors and 'scratch' at the printing.
image.jpg

Show me a Motorola transistor that can look like that.

EDIT:
Source image if you want to play along at home.
image.jpg
 
Last edited:

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Edraven99

Sr Member
RPF PREMIUM MEMBER
What are these "amplifiers" and how could you see anything clearly from that scene in the movie?

This was a quick and dirty photoshop but all I did was take one of these Solitron transistors and 'scratch' at the printing.
View attachment 524746

Show me a Motorola transistor that can look like that.

EDIT:
Source image if you want to play along at home.
View attachment 524749
Except though it looks like your "S" logo would have to be inverted (black S) in order for it to work... and it wouldn't explain the mark to the left of the S
 

thd9791

Master Member
RPF PREMIUM MEMBER
Yea, we can already see a full upwards ^ and even a third line, the beginng of an M or something like it on the real prop. Even with marking scratched off, Solitron logos don't have that.
 

thd9791

Master Member
RPF PREMIUM MEMBER
I'll give you that, it's a definite possibility.

To answer your other questions - when the saber falls we can see the shadows cast by the transistors and the washers themselves. The washer and the transistor cast very similarly thick shadows, full sized transistors sit much higher.

Roman Gomez has made excellent copies that are just the right size, ironically, and they match the height of DC Amplifiers, a type of transistor we've discussed on here.

$_35.JPG check the other thread discussing all this!
 

TheRealMcFly

Sr Member
RPF PREMIUM MEMBER
But doesn't the chronicles 3/4 view reveal that the washer is thinner than the replicas, sitting above the base ring of the transistor for that floating look?

Does the DC Amplifier part separate into two pieces so that a ring could be removed? I have never seen a research thread on these.

My feeling is tthe Solitron transistor is a better match than anything found yet, and provides an explanation for the anomalies that have remained unexplained even after many Motorola MA series finds.
image.jpg
 

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