Motorola AN-410 wanted

[The Phantom]

Barry Lennox wrote...

I'll be glad to give it a permanent spot on the net. You can
email it to me at hill_at_rowland-dotties-harvard-dots-edu

What's the URL of things you have given a permanent spot?

 

[Winfield Hill]

The Phantom wrote...

What's the URL of things you have given a permanent spot?

ftp://ftp.rowland.org/pub/hill/ with various subfolders.
And I've also used ftp://ftp.rowland.org/pub/EE-Lab/

Some of those folders are temporary and should probably
be deleted at some future date. Some have been emptied
already. OTOH, rapidly-increasing hard-drive size is
reducing the motivation to go back and do cleanup.

 

[Winfield Hill]

Barry Lennox wrote in the thread, Motorola AN-410 wanted,

An update;

Reference 3 of AN-410 was: "The Field-Effect Transistor at VHF" by
U. L. Rohde. Wireless World, Jan 1966.

I now have a copy of Rohde's article as well, and it's worth reading.

Barry has scanned the paper, for his jpgs and a pdf, point
your browser to ftp://ftp.rowland.org/pub/hill/RF-papers

 

[Winfield Hill]

Winfield Hill wrote...

Barry Lennox wrote in the thread, Motorola AN-410 wanted,

Barry has scanned the paper, for his jpgs and a pdf, point
your browser to ftp://ftp.rowland.org/pub/hill/RF-papers

The sepia-toned scan appears rather dim when viewed on screen, but
it printed acceptably with my monochrome HP5000 printer. Someone
may be inclined to process the jpg files for better contrast.

This 1966 paper is interesting in the evolution it reveals in the
world of JFETs and MOSFETs in the last 40 years. For example,
Rohde uses 2n3822 and 2n3823 JFETs in his sample circuits, but he
persists in calling them m.o.s. field-effect transistors, i.e.
MOSFETs, a usage that had already been assigned to insulated-gate
FETs by 1966 in the industry, IIRC. He also asserts that FETs are
better than "transistors" because they have a constant gm vs. Vd,
which makes me wonder what transistors he had been exposed to.

 

[John Popelish]

The sepia-toned scan appears rather dim when viewed on screen, but
it printed acceptably with my monochrome HP5000 printer. Someone
may be inclined to process the jpg files for better contrast.

(snip)

I expanded the contrast, cropped the edges, converted to
gray scale and saved as GIF, if you would like to see the
result.

 

[Winfield Hill]

John Popelish wrote...

I expanded the contrast, cropped the edges, converted to
gray scale and saved as GIF, if you would like to see the
result.

Great, I'll make a pdf and repost it to the ftp site, if you
email them to me at hill_at_rowland-dotties-harvard-dots-edu

 

[Fred Abse]

The sepia-toned scan appears rather dim when viewed on screen, but
it printed acceptably with my monochrome HP5000 printer. Someone
may be inclined to process the jpg files for better contrast.

Quick and dirty reprocess job posted to ABSE. Sharpened and converted to
1-bit B&W. The .pdf is considerably smaller.

I could possibly do a better job given the time.

 

[Winfield Hill]

Fred Abse wrote...

Quick and dirty reprocess job posted to ABSE. Sharpened and
converted to 1-bit B&W. The .pdf is considerably smaller.

I could possibly do a better job given the time.

Smaller is nice, but not as important as readability. The
1-bit threshold killed most of the already-bad subscripts.
How about a grey scale, like John said he used? Were you
able to read the subscripts on your computer screen after
the early processing steps?

 

[Fred Abse]

Smaller is nice, but not as important as readability. The
1-bit threshold killed most of the already-bad subscripts.
How about a grey scale, like John said he used? Were you
able to read the subscripts on your computer screen after
the early processing steps?

I tried gray scale, and it doesn't look any better than the original RGB

It isn't the 1-bit threshold, so much as sharpening a lossy jpg. There are
some low-level artifacts in there that screw things up. That's the problem
with jpeg encoding.

Converting the original directly to 1-bit looks even worse :-(

I'll play some more ...

 

[Winfield Hill]

John Popelish wrote...

I expanded the contrast, cropped the edges, converted to
gray scale and saved as GIF, if you would like to see the
result.

See ftp://ftp.rowland.org/pub/hill/RF-papers for the pdf
version of John's gifs, Rohde(1966)_The-FET-at-VHF_1.pdf