ephemt as diode

Like this:

PADS doesn't do wire hopping! LT Spice, either. Lazy programmers.

The Europeans keep naming units, and the reciprocal of units, after dead Europeans.

It's almost a current source!

Well is it a "mushy" current source or a "hard assed" current source?

I could probably just calculate it based on the schematic and tube data...

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And steam engine parts.

I mowed a lot of lawns as a kid, to be able to buy some decent tools. Most of the parts were from dead radios & TVs. My first test equipment was pretty much junk, and a lot of it didn't work when I got it home.

Your sketches are part of the formal path?

That makes some sense, though our CAD system takes care of multiple versions. The schematic can be generated with any of the variations. It helps that both are in sync. The BOM can be recreated at any point. It's what manufacturing builds to, so it is the controlled document, though.

I do a one-mile circuit around the building three times a day, unless I have a wall to wall meetings. There are no stairs, though. Stairs aren't common because land and energy are cheap. It's easier to spread out than go up.

>

Am 20.12.2015 um 18:26 schrieb Joerg:

Yes, and after the 2nd photo copy that is a fat connection dot.

regards, Gerhard

Am 20.12.2015 um 18:26 schrieb Joerg:

Kiddie. Condensers are in cm, not in mmf. At least in metric regions.

regards, Gerhard

(I think 1 cm is abt 1.11 pF, IIRC; where is the bottle with that Gerontol forte?...)

When I was with my parents, I didn't have anything more than a Radio Shack multimeter and some audio gear, so I specialized in projects that could talk to entertainment radios, e.g. wireless mics and tone controls. I did the dead-TV thing too--I used to get rid of the picture tubes by stuffing them in a Rubbermaid garbage can and shooting them with my slingshot from a distance. Fun.

I really wanted to build more of the stuff from the ARRL Handbook, but couldn't afford the parts, so I never bothered getting a license. Built a few cool power supplies though--those old Admiral 25-inch colour sets had some serious mains transformers in them. One day when I was 14, I just about killed myself learning the keep-one-hand-in-your-pocket rule. I was checking out a ~1kV supply built from a 400-0-400 transformer and bridge rectifier. (It had a choke-only filter because all the caps I had were can types with the case ground, rated 450 WVDC at most.) Also stuff like arc lamps made from the carbon rods from D cell batteries, running off the 120V AC mains with an electric teakettle for ballast. My guardian angel was working overtime at that point, just keeping me alive. ;)

In high school, I spent quite a lot of time trying unsuccessfully to get a WW2 T19 MK II tank transceiver working. It had a lot of cool stuff in it, including (iirc) a UHF superregen using an E1138 tube that had two plate/grid/something caps on it.

When I got to university (I was still 16) I could borrow scopes and things, but I was pretty busy for heavy-duty hobby stuff at that point. (I also had a steady girlfriend, which does take up a bit of time and money!)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

Embarcadero IIRC. But really, you can e-mail them if you want to discuss their codebase and software direction.

I'm sure they wouldn't be thrilled...

(considering how bizarre their management direction is, relative to the desires of their userbase, and the direction of modern PC software as a whole.)

Tim

--
Seven Transistor Labs 
Electrical Engineering Consultation 
Website: http://seventransistorlabs.com

I forget which variation this was, but something like,

The right hand region is "saturation", i.e., Rds(on) as it were. Was looking for < 100V drop at 100mA, preferably 50V. Tubes with heaters 6.3V >0.6A are required to achieve this (cathode size is akin to MOSFET die area).

The feedback obviously was overly generous in this case, giving negative resistance. That can be tuned by changing the voltage dividers.

When the error amp or feedback side runs into saturation or cutoff, current shoots up again. I wanted < 100V for this, which it seems is okay.

Without P-tubes, you have to compromise between the divider ratio (a lower ratio means lower common mode gain and therefore a wider operating range for the error amp) and the general lack of gain in the system (the output is a follower, and the error amp might have mu ~ 50, so you can't possibly have <

1/50 gain in the divider!). As a result, the transitions between saturation/cutoff and the linear band are quite soft, and the linear band tends to be overly narrow.

I must say, I'm glad that lateral PNP exists...and then some. :^)

Tim

--
Seven Transistor Labs 
Electrical Engineering Consultation 
Website: http://seventransistorlabs.com

Am 20.12.2015 um 17:04 schrieb M Philbrook:

Hilarious... The words "Delphi", "Altium" and "fewer bugs" within a few lines. I have spent nearly $2k of MY money for this year's support and I didn't even bother to download the Version 16; just follow the user discussion site and you know why. Altium is firmly bolted to the Microsoft world; just run it on a virtual machine that lacks the current level of DirectX 3D support and you'll see what you get. Well, not much. Empty windows where your board is supposed to be.

No warning, nothing. I could get a display of my board with Orcad, or Racal Redboard, or later PADS, some 30 years ago on a Compaq 286. Maybe not really fast, but it worked.

A customer of mine has written his design data base in Delphi, fun to watch that, his search for Delphi developers and the developer wanna-bes. NOT. I don't want to engage in badmouthing anything, I feel more like the Buddha of compassion.

Borland, who?

And I must say that I had Turbo-Pascal on my Z80 and loved it, Pascal MT+, wrote a UCSD p-code machine for the Z8000 and for Prof. Tannenbaum's compiler, and at the univ, we had a sign at the door of our room that read "Phearless Pascal Phreaks" but if the horse is definitely dead, it's time to dismount. And the horse is dead for 20 years by now.

regards, Gerhard

I built a radio from a kit, on my eighth birthday, in 1960. Three years later I was working part time in a TV shop where I got a steady supply of free B&W TVs, for free. I repaired and sold a lot of them, and scrapped the worst of them. At one point I had over 25 old CRTs in the rafters of the garage. I was told to get rid of them, so I filled a

32 gallon steel garbage can with crushed glass. No sling shot, so I used a 16 oz framing hammer. tick the neck down into the can, and hit the faceplate until it imploded. :)

My first scope was an Eico 460 with a bad power transformer. Typical of cheap, hobby grade scopes the CRT filament winding had shorted to the core. I added a separate filament transformer, and had it running.

I graduated in 1970, and was working full time in a TV shop. I was repairing things on the side, that the shop wouldn't touch. That included an old, home brew Amateur radio receiver that a very old man had built as a young ham. He had lost the drawings he had made, and the magazines that had the original construction project. He had asked all over town, and no one would touch it. Finally, someone told him that I might be able to help. It took me about 15 minutes with a VTVM, and the RCA receiving tube handbook to find an open resistor. The old man was delighted to have it working again, and it was interesting to troubleshoot a poorly built old radio that had been built mostly of used or surplus parts.

In case I'm off line again before Christmas, I wish you a Blessed Christmas, my friend. :)

I had to make a trip to the VA hospital for a very painful infection, and I may have to go back. The prescribed antibiotics didn't do their job. The swelling is down some, but it is still very tender.

Me too. I got across the plate winding of a teevee transformer. It left me shaking for the rest of the day.

The filament winding was fun for igniting pencil leads.

By the time I was 12, I had an Eico VTVM and a Heathkit oscilloscope. Later I got a 5 MHz Knight-Kit DC-coupled, triggered-sweep scope, all tubes. It even had DC unblanking.

I worked summers in the physics department equipment shop at LSUNO, where I got exposed to serious electronics, and got to design stuff. They faked my student registration in order to be able to pay me. I became student number 10,000 and made 85 cents per hour. I learned a lot of great stuff there.

A lot of people have been good to me. I try to return the debt to whoever keeps track of karma.

There was fabulous WWII surplus stuff, practically sold by the pound. PMTs. Flashtubes and oil caps. RF stuff. Dynamotors. Synchros. Klystrons. Crystals and tubes. My uncle Sheldon, who taught me electronics, has a shed full of fun stuff that he'd stolen from the Army.

I gather that's the event to which you owe your good looks. ;)

A blessed Christmas to you too, Mike. We'll keep you in our prayers

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC 
Optics, Electro-optics, Photonics, Analog Electronics 

160 North State Road #203 
Briarcliff Manor NY 10510 

hobbs at electrooptical dot net 
http://electrooptical.net

That's why I switched from Orcad to Eagle. It's a bit clunky but always works and that's most important to me. In a similar way I switched from PSpice to LTSpice. Not because it's free but because it isn't buggy. I don't have time for bugs and IMHO $2k is more wisely spent on things like a mountain bike. And I did spend it on that. Also, I abhor the concept of a de facto support tax like I had to spend on Mathcad where that was mandatory in the year of purchase.

I mostly do not see the value in highfalutin super expensive CAD "solutions" and I am pretty certain that I will be able to live without them until I put my teeth in a jar for cleaning.

[...]

--
Regards, Joerg 

http://www.analogconsultants.com/

They are in the path in that they are the thing the first CAD schematic is created from. They are only reference sketches after that, and have no formal function in the document system. They are never released. The CAD files are official.

Most of my engineers prefer to enter the PADS schematic themselves. The layout people prefer my sketches, so they can do the design entry their way.

Our most recent engineering hire is a young person who recently graduated from an engineering school in Mexico. She likes to draw too, so the tradition endures.

Our BOMs are controlled, and manufacturing has the option to create sub or partial assemblies as it suits them. We create a new BOM when we create a new dash number, or edit a BOM when an ECO changes values, but we never revise released PCB schematics or layouts or gerbers. It works. Manufacturing knows everything about every serialized product, its full configuration and history.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

Don't go around being right. Nobody likes people who are right.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com

That's a very sinister thing to say.

Tim

--
Seven Transistor Labs 
Electrical Engineering Consultation 
Website: http://seventransistorlabs.com