Only RCA i got is 2N3055, will test them both in last "quad 405 clone" ...
Also got me some old "JPS" 2N3773 and some "Toshiba" 2SD424 ...
All are NOS, never mounted, will see what brand - model will perform the best ...
And yes, got me some old 2n3055 marked wirh bold "Beta" - "β" ...
I also have 2n3055 with "Beta" - "β". Here in Bulgaria they are known very well to be original but very badly made - Hfe 15 is normal for them. The "Beta" comes from an old romanian semiconductor factory or town i'm not shure - "BANIASA".
So like i sad before original but badly made pieces of a junk.
I also have some chips with the "Beta" logo and i dont know what this chips are.
Attachments
I also have some chips with the "Beta" logo and i dont know what this chips are.
That chip is actually a Hex inverter, SN74LS04 (7404) . CDB404 is probably a custom marking by that Romanian factory.
SN74LS04
That chip is actually a Hex inverter, SN74LS04 (7404) . CDB404 is probably a custom marking by that Romanian factory.
SN74LS04
Thanks very much for the info!
Hmm....that second picture... punched circle on the bottom of that transistor. Looks suspicious and it's a typical bad sign on counterfeits
Hum, why is that ?
I got this set in in my pyle of parts for about 20 years ...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Dunno if Chinese guys make fakes back in time ... !
Seems like 100% real; if it's 20 years old. still it holds the marking even after kept as pile
The second puched circle with plug confirms the heat spread plat mounting. (making a punch hole and metal plug(rivet) requires more workmanship which counterfeits wont do happily
Vijay
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Well, since these transistors are vintage and I doubt komigenie will use them in future (he kept them 20 years on the shelf!) so I suggest him to grab a hacksaw and take off the cap so we can see what the heck is in there!
Edit: correct me if I'm wrong, did Toshiba actually ever manufactured 2N3773?
Edit: correct me if I'm wrong, did Toshiba actually ever manufactured 2N3773?
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what!
I have various ages of amplifiers fitted with Toshiba To3 2n3773 transistors going back to the late 70s.
I have a copy of Toshiba's datasheet from the 80s.
Toshiba must have a very short memory or you asked the wrong question.
you are wrong.correct me if I'm wrong, did Toshiba actually ever manufactured 2N3773?
I and various other Members have seen them.
Read the thread !
Well, since these transistors are vintage and I doubt komigenie will use them in future (he kept them 20 years on the shelf!) so I suggest him to grab a hacksaw and take off the cap so we can see what the heck is in there!
Only RCA i got is 2N3055, will test them both in last "quad 405 clone" ...
Oh, I'm gonna heat'em up with soldering iron all right ...
Toshiba also made ProElectron labeled transistors like the BU205. They were used in b/w television sets in W-Germany (Saba?!) and Romania. The romanian tv-manufacturers co-operate in the past with National from Japan. The transistors look like the ones presented by burbeck (the brand name Toshiba written with round letters).
you are wrong.
I and various other Members have seen them.
Read the thread !
Hi Andrew,
A fellow from Brazil and DIYAudio member, Jyazbek, found out in his office an old Toshiba Databook.
http://www.jyazbek.com.br/docs/Toshiba_2N_series_power_transistors.pdf
I think it closes the question about fake 2n Toshibas.
Anyway, the care about new units bought from somewhere remains necessary.
Regards
The data sheet also explains why the Toshiba 2N3773 I had didn't work very well in an audio amplifier, Hfe=4 at 1A at 50Khz.
The Motorola were 4Mhz devices after the early 70s.
I can be wrong, but I think at the end of 60´s and beginning of 70´s the japanese companies were trying to reach the americans on this matter.
Regards,
found out
I saw something pretty similar just the other day, had Chinese scribbled on top.
"I can be wrong, but I think at the end of 60´s and beginning of 70´s the japanese companies were trying to reach the americans on this matter."
And they did, and put numbers like 2SD555 on them.
The Toshiba 2N3773 I purchased around 1988 were stone slow, and when the amplifier clipped they stuck to the rail, got shoot-thru, and blew up.
I had some Solitron that had the same issues, they were really meant to be power supply regulator pass transistors.
And they did, and put numbers like 2SD555 on them.
The Toshiba 2N3773 I purchased around 1988 were stone slow, and when the amplifier clipped they stuck to the rail, got shoot-thru, and blew up.
I had some Solitron that had the same issues, they were really meant to be power supply regulator pass transistors.
The data sheet also explains why the Toshiba 2N3773 I had didn't work very well in an audio amplifier, Hfe=4 at 1A at 50Khz.
The Motorola were 4Mhz devices after the early 70s.
200 KHz fT? .Even the RCA hometaxials could beat that by a factor of 4 or 5. The 2N6254 would stick to the rails like glue, but never blow up, and eat a 3055 for breakfast in a beta contest.
Maybe Toshiba never really got the single-diffused process perfected since they were working on all the higher fT stuff when Moto/RCA/GE could only crank out 4 MHz at best.
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