Japanese AF114 Transistors ?!

[camtechman]

Just acquired a set of Japanese ("Made In Japan") Juliette WT-6 (27Mhz) Walkie Talkies. Although in very good cosmetic condition & full working order, like all my gear, I couldn't resist opening them up.

Imagine my suprise to see 3x AF11X style transistors in each unit in the RX & TX stage : 1x 2SA70 (T.I.T.S. equiv given as an AF124) and a pair of AF114's.

The 2SA70 is marked as Matsushita but the AF114's had no manufacturers name, although the AF114 was printed in Mullard style type .

Suspecting the AF114's to be recent replacements I flipped the circuit board over and, on close inspection, the solder joints for the AF114's were undisturbed & original !

Any other examples of AF11X's use elsewhere abroad?

[Maarten]

Philips and Matsushita were business partners around that time and may have done some cross-licensing and exchange of parts, so I'm not too surprised even though I haven't seen Japanese AF114's before.

[marconi_pete]

I've come across these before in Japanese imported sets and did think it to be a bit odd, but given the link with Philips it's beginning to make sense. I think i've also got an early 60's american built transistor set somewhere which I remember as being odd as it a couple of AF114's in it but can't be sure if they're original. the solder track did look to be undisturbed though. Will dig it out again and have another look.

[Refugee]

I have made an even better discovery, albeit a somewhat rusty specimen it is indeed a TO7 package but this time with Japanese branding and the part number 2SA69.

http://alltransistors.com/transistor...ransistor=8715

[Maarten]

It makes me wonder... Did the Matsushita ones also suffer from tin-dendrites?

[G6Tanuki]

Originally Posted by Refugee

I have made an even better discovery, albeit a somewhat rusty specimen it is indeed a TO7 package but this time with Japanese branding and the part number 2SA69

I have seen similar ones in 1960s Japanese transistor radios, they were branded, if my memory serves me right, "TEN". There were similar "TEN" ones in TO-1 style cases in the audio stages..

[Refugee]

It is the only one I have and I am pretty sure it is all right but a sample of one is not exactly representative.

[Station X]

One post moved to a new thread here:-

https://www.vintage-radio.net/forum/...d.php?t=121255

[mhennessy]

Originally Posted by Maarten

It makes me wonder... Did the Matsushita ones also suffer from tin-dendrites?

Tin whiskers aren't dendrites

Looking at the picture, I'd be suspicious of what I see in the seam. It could just be debris, of course. Simple enough to put a multimeter across all 3 electrodes and the can...

[FERNSEH]

The 2SA70 is the equivalent of the European OC170. Same casing with four wires.
http://www.radiomuseum.org/tubes/tube_2sa70.html

The 2SA71 is the equivalent of the OC171 which was later replaced by the AF114 and AF115.
http://www.radiomuseum.org/tubes/tube_oc171.html
http://www.radiomuseum.org/tubes/tube_2sa71.html

DFWB.

[FERNSEH]

List of the transistors and diodes employed in the 1966 National (Panasonic) model RF1006L.

Note the European type diodes. Was there any technical links between Matsushita Electric and Philips?

DFWB.

[TrevorG3VLF]

Originally Posted by mhennessy

Tin whiskers aren't dendrites

Really? Please define.

[mhennessy]

See https://en.wikipedia.org/wiki/Whisker_%28metallurgy%29

Metal whiskers differ from metallic dendrites in several respects; dendrites are fern-shaped, and grow across the surface of the metal, while metal whiskers are hair-like and project at a right angle to the surface. Dendrite growth requires moisture capable of dissolving the metal into a solution of metal ions which are then redistributed by electromigration in the presence of an electromagnetic field. While the precise mechanism for whisker formation remains unknown, it is known that whisker formation does not require either dissolution of the metal or the presence of an electromagnetic field.

Plenty more out there. Check the NASA site if you haven't already seen it: http://nepp.nasa.gov/whisker/

Don't forget this: http://nepp.nasa.gov/whisker/anecdot...tor/index.html

Scary stuff

[Maarten]

Originally Posted by FERNSEH

Note the European type diodes. Was there any technical links between Matsushita Electric and Philips?

I think my previous comment on this explains most of it.

Originally Posted by Maarten

Philips and Matsushita were business partners around that time and may have done some cross-licensing and exchange of parts, so I'm not too surprised even though I haven't seen Japanese AF114's before.