Transmission1

Hi guys.

I found this excellent little video on YouTube. If you're unsure about testing your 1969 transistors for faults then this is the perfect video for you. It's short, informative, easy to follow and directly to the point. No bells or whistles or someone rambling on. It's a matter of fact clip which anyone can follow. This guide will also work with any other NPN transistor such as the 2sc2166 and 2sc2312.

https://youtu.be/xo6PvI1sXyg

The trouble with all this is how do you tell in advance if you are buying a genuine article or a Chinese fake?
Many UK wholesalers are actually just outlets based in the UK, selling the usual Chinese rubbish.
It's getting really hard to ensure you are getting a proper product.
I don't know what can be done about it, but sadly China is flooding the world with cheap tat and fake gear.

ghost123uk wrote: ↑08 Jun 2018, 13:48 The trouble with all this is how do you tell in advance if you are buying a genuine article or a Chinese fake?

Most of the time the fakes are pretty easy to spot . There's a good thread on here somewhere about it . A safe rule of thumb would be not to buy any from China at all . Most NOS ones tend to appear within Europe , and the States .

The only original 2312s I can see at the moment are these ones :
Check the slight indentations on the main body . The legs should probably be a bit darkened over time . Check the size of the Mitsubishi symbol , plus the letters on it .

Sammy

That way you can check only if transistor is not defected.
In attachment is a circuit which will show you if transistor is legit or counterfeit. You go to the shop and you know before buy. Just put transistor to the socket and when led is lit, it is legit.
Kudos to sp8jux who invented that device. Chris

ch25 wrote: ↑08 Jun 2018, 16:43 You go to the shop and you know before buy.

Nice little circuit there Chris . The only problem is . Who goes into a shop these days to buy 2166/1969 and 2312s ? They're not made any more . Anyway , it's a useful little tester regardless .

Sammy

I built that, because even 2078 are fake in local shops here. 1966 replacement is no problem to buy locally here. Eleflow HFR-20W 7 quid.
Online you can't go wrong with eleflow parts.
Chris

ch25 wrote: ↑08 Jun 2018, 18:00 Online you can't go wrong with eleflow parts.
Chris

I agree . Saying that I've only had to ever buy 2 transistors from them . I haven't had that many radios with driver/final problems , so I don't have to replace them often . And on top of that I try and buy old scrap radios for parts when I can .

There are some NOS 1969's currently on eBay. £11 a piece with P&P, but they are from a trusted seller.

https://rover.ebay.com/rover/0/0/0?mpre ... 3007169746

ch25 wrote: ↑08 Jun 2018, 16:43 That way you can check only if transistor is not defected.
In attachment is a circuit which will show you if transistor is legit or counterfeit. You go to the shop and you know before buy. Just put transistor to the socket and when led is lit, it is legit.
Kudos to sp8jux who invented that device.
tester rf.jpg
Chris

Hi Chris .

Just looking at the diagram you posted again . Why would a fake not light the led ? Don't they like working at 27Mhz ?

Sammy

Not at all. You can use 40MHz crystal to be more sure

ch25 wrote: ↑11 Jun 2018, 14:02 Not at all. You can use 40MHz crystal to be more sure

OK . Thanks !

Bought three 2312s from my local dealer last week for 10,00 Euro. A bargin for sure with a matched pair. But they were the last ones and i will keep them. They are very rare here in DL and we have no Eleflow dealer.

If anybody needs a 27.000 crystal, I have them in stock.

It is very helpful information. Thanks for sharing.

nayam wrote: ↑26 Aug 2019, 11:20 It is very helpful information. Thanks for sharing.