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Old 30th January 2010, 07:04 PM   #111
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Cliff, think of the advantages we had, starting at the beginning! 68 next month.
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Old 30th January 2010, 07:14 PM   #112
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Barrie was at Mullard in Southampton and I used to visit him there - I was just a young oik, so I doubt if he would ever remember me.

702s were a real pig to wafer test. In those days we had only semi-automatic wafer probers with individual wired probes, so no performance boards. Just a kludge of stuff trying to stop the DUT from oscillating, which it usually did due to the process being all over the place. I mean, step and repeat was MECHANICAL!!, with the camera on a few tons of concrete to try and damp the vibrations.

Kids these days, don't know what ......

Cliff, 66 and rising
You would be surprised, I'll see Barrie on Saturday and ask him. Did you get a chance to see the IEEE Spectrum article? They even got some pictures of him as a teenager with a soldering iron in hand?
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Old 31st January 2010, 02:44 AM   #113
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I don't think Ivey; I'm still waiting till PCBCAD40 arrives. After that I will let you know how happy I am with it.
I got it today, installed. User interface is... hmmm.... very specific. Let's get used to it, then I will tell how convenient it is.
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Old 31st January 2010, 01:08 PM   #114
Ivey is offline Ivey  United States
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Default Cliff

They bought a lot of equipment from several companies, with one being Delco, out of St.Louis. Delco made some really good transistors for the Consumer Market. GMC, as we all know, really screwed them up. As Ford has done with Philco. Car Companies>>>>>>>>>>>>>>>>>>>.

No the MPS404 and MPS404A's were not made to be used as choppers. But I am sure someone used it for it. But they were made to be silicon replacements for the 2N404 and 2N404A.

Scott the 2N404 and 2N404A's, were just real good and stable Ge transistors. Most Ge transistors had low ft ratings, until the 2N13XX series.

There were other Ge that had good ft prior to the 2N13XX series. But they proved to be less stable and reliable.

I have a sheet scanner and copier, so I can not scan the book. But I will go to Office Depot and copy it. And scan it through, maybe from that, you get can get a look see at it.

It is nice to know that there is someone a little younger than me there, Cliff.

As you all know Nelson Pass is catching up to us. Soon he will be moving at a lighting fast 4 miles per hour.

Take Care

Ivey

Last edited by Ivey; 31st January 2010 at 01:11 PM. Reason: grammar
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Old 31st January 2010, 01:18 PM   #115
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Default Wavebourn

So, it arrived and working. You got to tell me how good it is; once you get to understand it fully.

If is good, and not too big. Email me a copy, and I'll settle the matter with its owner; Nigelwright7557.

Nigel is a guitar player, like I am. Only my fingers do not move fast as before. So I play a little slower now.

Take Care

Ivey
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Old 31st January 2010, 05:21 PM   #116
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Ivey, I don't want to be too critical, BUT the data sheet says that these specific devices were made for choppers. Also, what do you do with Vbe? It is not compatible with Ge.
Please understand that I worked with Ge too, at a design level, including the 2N404.
The MPS404A MIGHT be a crude replacement for the 2N404, but not an exact one.

Last edited by john curl; 31st January 2010 at 05:32 PM.
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Old 31st January 2010, 05:26 PM   #117
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Delco did indeed make interesting devices. In 1966, we started using the DTS-423 for switching power supplies. It is a 400V power device and this series and its cheaper cousin, the DTS-413. Motorola made a clone, later, and this became the output devices for Carver's Phase Linear 700.

Last edited by john curl; 31st January 2010 at 05:31 PM.
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Old 2nd February 2010, 02:55 AM   #118
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Default John

Yes, Delco made and designed some really good items. I once had a 27 page circuit handbook that they published in 1965, that included only hifi power amplifiers. I loan it a person who never returned, which only confirms my rule on never loaning out my publications.

I only have one of their designs left. I am looking at it now, It is a 50watt hifi BJT power amp, using DTS-107 transistors. This design came out long before the RCA 70watt design, that became so popular.

No John, you are not being critical, I went on the internet and check out what you are saying. I saw also, what Motorola had done, they id the transistor as a chopper.

Really burns my butt.

But I when post the inform on the forum. You'll see it, and you will not believe your eyes.

It appears they will do anything for a dollar.

So tomorrow, I'll get started on it.



Take Care

Ivey
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Old 19th February 2010, 09:52 PM   #119
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Barretta:

ARNLF:

Our English speaking cousins, the British, developed jet engine technology in 1936-39. In 1944 they developed the allies first operational jet fighter.

And they did not share that technology with us Americans; who had fought and die side by side with them from 1940 to 1945. Until 1944.

That delay on the part of our British cousins, open some deep wounds. Which led America to drag her feet in sharing with our British cousins, all the secret technology we took from Germany.

That delay on the British part, cause us to enter into the Korean Conflict with the mediocre P-80 Shooting Star. Where we lost some flyers to Migs. Those 10 years, caused us to delay our development of a swept wing fighter until 1950 with the F-86 Sabre.

Ivey

With the greatest respect I cannot let this pass without comment. It is my understanding that Great Britain and the USA agreed an exchange of information on jet technology towards the end of the war. Great Britain gave the US her secrets...... and got nothing in return.
Who should feel aggrieved?
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Old 19th February 2010, 10:28 PM   #120
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Those 10 years, caused us to delay our development of a swept wing fighter until 1950 with the F-86 Sabre.

Ivey

The Me 262 influenced the designs of post-war aircraft such as the North American F-86 and Boeing B-47.

Messerschmitt Me 262 - Wikipedia, the free encyclopedia
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