Hugh,
You must be the only one this ever happened to ;)
Didier KO4BB
On Sun, Feb 10, 2019, 7:06 PM Rice, Hugh (IPH Writing Systems) <
hugh.r...@hp.com> wrote:
>
> Putting things in writing and disclosing it to the public is a risky
> undertaking!
>
> Best wishes,
> Hugh
>
On 10/2/19 11:18 pm, Rice, Hugh (IPH Writing Systems) wrote:
> The AC transformer in the 5061A/B was from HPs transformer organization (HP
> actually made their own transformers for many years), and whoever designed
> the original power system left a lot of "brown out" margin in the system.
Sorry, perhaps off-topic but relevant given the pursuit of mineral
mining globally. In 1968, the U.S. Bureau of Mines had a very accurate
model (pre-econometric, if there is such a thing) of Mica production in
India down to the State level (primarily Bihar - the poorest state in
India). As a
on behalf of Mark Sims
Sent: Sunday, February 10, 2019 5:37 PM
To: time-nuts@lists.febo.com
Subject: [time-nuts] HP Stories: Battery Chargers, and a fading idolization of
HP
Back in the late 70's I worked for a mini-computer company. They were a
horrendous paper-work factory... spec after
On 2/10/19 4:36 PM, Tom Van Baak wrote:
Christopher Shawn McGahey's wrote his phd at Georgia Tech on the subject,
and it sorts a lot of facts from fiction.
"HARNESSING NATURE'S TIMEKEEPER: A HISTORY OF THE PIEZOELECTRIC QUARTZ CRYSTAL
TECHNOLOGICAL COMMUNITY (1880-1959)"
Back in the late 70's I worked for a mini-computer company. They were a
horrendous paper-work factory... spec after needless/useless/virtually
identical documentation requirements. I wrote one document where I put all
the timings in units of "ffn"... femto-fortnights. It was over three
Mica is a sheet silicate mineral little or no carbon present.
Bruce
> On 11 February 2019 at 11:15 Bob Bownes wrote:
>
>
> >
> > Yes, those brown roughly 1" square caps used intact sheets of mica as
> > dielectric. You can easily split the mineral into uniform, thin,
> > transparent sheets.
isclosing it to the public is a risky
undertaking!
Best wishes,
Hugh
From: time-nuts On Behalf Of Luca
Sent: Sunday, February 10, 2019 8:55 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] HP Stories: Battery Chargers, and a fading idolization of
HP
Thanks Hugh for
> Christopher Shawn McGahey's wrote his phd at Georgia Tech on the subject,
> and it sorts a lot of facts from fiction.
"HARNESSING NATURE'S TIMEKEEPER: A HISTORY OF THE PIEZOELECTRIC QUARTZ CRYSTAL
TECHNOLOGICAL COMMUNITY (1880-1959)"
>
> Yes, those brown roughly 1" square caps used intact sheets of mica as
> dielectric. You can easily split the mineral into uniform, thin, transparent
> sheets.
Beware inclusions that will make the surface rough and change the behavior,
particularly breakdown voltages.
> The reconstituted
> were made from large contiguous chunks of mica. A some point after
> the war, the mica mines were played out, similar to the quartz mines,
> and only small pieces of mica were available. The capacitor vendors
> made "reconstituted" mica out of crumbs. The crystal vendors didn't
>
On 2/10/2019 4:35 AM, Rice, Hugh (IPH Writing Systems) wrote:
Somewhere over the years I picked up this line: “A good engineer is a lazy
engineer. They are always looking for the easiest way to do things.” The
designer of the 5061A battery charger was definitely not a lazy engineer.
In reading back over my sarcastic description of the 5061A battery charger, I
was pretty hard on the unnamed designer of that circuit. I did find a
schematic of an older generation batter charger for the 5061A, and it had the
same basic implementation.
As far as I know, the circuit, in all
time and frequency measurement
; Rice, Hugh (IPH Writing Systems)
Cc: 'hug...@yahoo.com'
Subject: Re: [time-nuts] HP Stories: Battery Chargers, and a fading idolization
of HP
Hugh,
I notice your design, like all other HP designs I have seen from that era,
operates with a very high margin
Of Adrian Godwin
Sent: Sunday, February 10, 2019 3:57 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] HP Stories: Battery Chargers, and a fading idolization
of HP
The schematics are so good - easy to read, lots of context. Even some
off-board parts shown so y
Thanks Hugh for the story, and thanks for the schematic!
Quite interesting.
There is a little strangeness: the wave clipper darlington transistor Q1 is
marked as 1854-0611, equivalent to the standard darlington 2N6055. But why
there is a simple 2N3055 in the picture? Some sort of version update
Well lately I have been disappointed with the quality of writing of the
manuals. Not just HP, but I do expect better from them. Typos, poor grammar,
occasionally poor content. Very little said about errors that appear on
screen, for instance.
Sometimes I wonder if the circuits and software
Before I worked for HP, I used to read HP manuals like they were
textbooks. I was like Hugh in that I thought everything HP
did must be great. So I decided to reverse engineer a 200 to
300 MHz VCO used in a 0 to 100 MHz spectrum analyzer plug in.
The manual only gave an - number for the
Great story and like all things as you get to know them realities sink in.
The great thing is getting past what you thought and appreciating that
things work and have long lives.
Have to say I always enjoyed reading the HP and Tek manuals because as an
outsider you did learn. Granted I normally
The schematics are so good - easy to read, lots of context. Even some
off-board parts shown so you can see where the signal ends up. Notes about
the function and adjustment. You can learn a lot from them. Manuals were
worth having.
So many of today's schematics are little more than a netlist : a
Hugh,
I notice your design, like all other HP designs I have seen from
that era, operates with a very high margin for low mains voltage.
Do you happen to remember what HP's design criteria were for this ?
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP
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