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Hi Arthur,

I am currently using a laptop to act as the console terminal. It works
just fine, but then again, the laptop works better and is decades faster
than the 8/E, so might just as well not use the 8/E at all!

I am looking for a console terminal that is age appropriate to the 8/E.
A 4010, or 4012 looks nice, and was used on 8/E's in the research world.
At least the 4010 is built with ttl chips, like the 8/E.

A DecWriter or ASR33 would be more authentic, though.

-Chuck

arthurok wrote:

On Wednesday 07 February 2007 18:39, you wrote:

My late father used to say "Why do it simply, when complicated works
well too" (It looses something in translation)

I guess it was "Warum einfach wenn Mann komplizieren kann" or somesuch. My
German is pretty rusty.

To me, using an unknown scope is complicating things. Mind you, I wasn't
anywhere advocating a full calibration -- just a decent enough check to make
sure that your 100MHz mainframe and preamps are where they are supposed to
be.

Maybe my problem was that I was almost always getting the mainframes and
plugins separately, and the plugins were always in lots and always seemed to
be someones "reject" pile. 90% of them calibrated just fine, though.

I guess the proper advice would be: get a 7603 with plugins, coming out of
service in a lab somewhere, with a calibration sticker with dates in last 7-8
years. That'd be safe enough I guess.

Kuba

You don't NEED anything like an RF RMS voltmeter. or phase detector. A
diode probe on a VTVM or very minimal scope will do just fine. You tune
for the typical 'rabbit ears' [flat phase] response.

Phase MIGHT be important in a wide band microwave communication system
using BPSK or QPSK or NPSK, but not in audio gear.

Hmm, I've been tuning a lot of 2nd order 500Hz low pass Bessel filters and the
most accurate way of tuning them was to tune for proper phase at cutoff
frequency. IIRC it was supposed to be 45 debgrees. Frankly said, I don't
quite know how else I'd go about tuning them anywhere near same accuracy -
you can detect small phase changes very well, while detecting the peak of
amplitude response *to the same accuracy* is kinda hard.

I've seen a similar thing in narrow bandpass filters: the peak of the response
is where your amplitude envelope slope is zero, so by minimally tweaking the
tuning you get close to zero change in amplitude. So the only way I found to
do such tuning with good accuracy was to look at phase. But then I didn't
really have much RF experience, so I may be talking complete BS. I'm only
relating what has worked for me.

Cheers, Kuba

Well Johnny,
You already discover the name of the game. I did that some year ago looking
onto Ebay stuff...
Now with (I think) 5Hz min BW and 100dB dynamic range how it is not "good
enough" to read audio distortions dB down (max up to 100dB down) from the
carrier?
I think this HP machine is as powerful as todays Microwave Spectrum Analyzers
with similar parameters dealing with RF.


Greg


At 04:43 AM 2/8/07 -0800, Johnny Chapman wrote:

Greg, ahhhhhhhhh the HP 3581A. Read that they are
good thingies. The price on 'em is good too. I'd
prefer a 3580A w/ the crt.

However, they aren't that great at S/N measurements of
some modern digital sources and killer amplifiers.

I'd really like to know how an Tek AF501 would compare
to the 3581A. You can surely get an 3581A more
cheaply and consistenly.

Yeah! Audio Discussions on my B-Day! 33 years old!
Hee Hee; I'll be 40 and dirt before ya know it
(definitely no age bashing here; just little fun; I
respect age/wisdom and wanna live way out yonder!).

Laters.

__________________________________________________________
Want to start your own business?
Learn how on Yahoo! Small Business.

<>

Emacs!

I am trying to source Some Japnese transistors or get some

equivalent

info. ( 2SC2909)
Any help most welcome

Available in the UK from for 20p each (40cents).

Craig

Greg, ahhhhhhhhh the HP 3581A. Read that they are
good thingies. The price on 'em is good too. I'd
prefer a 3580A w/ the crt.

However, they aren't that great at S/N measurements of
some modern digital sources and killer amplifiers.

I'd really like to know how an Tek AF501 would compare
to the 3581A. You can surely get an 3581A more
cheaply and consistenly.

Yeah! Audio Discussions on my B-Day! 33 years old!
Hee Hee; I'll be 40 and dirt before ya know it
(definitely no age bashing here; just little fun; I
respect age/wisdom and wanna live way out yonder!).

Laters.




____________________________________________________________________________________
Want to start your own business?
Learn how on Yahoo! Small Business.

Thanks for the post Ash!

Check the specs on the Sencore SG80. I believe it to
be a bit better and a younger product by maybe ten
years. I hardly use it, but when needed, BAM! I
generally am brand loyal almost to a fault!

I've first seen them in the install/maintenance bays
of GM dealerships. AC/Delco is the parent company of
Rockford-Fosgate!




____________________________________________________________________________________
Yahoo! Music Unlimited
Access over 1 million songs.

On Thu, 08 Feb 2007 03:21:49 +0100, arthurok <arthurok@...> wrote:

because of modern technology
you arent paying very much for all those modes
the software programming is amortized over a tremendous number of units

And they don't seem to test the software at all, ever, so that saves lotsa money too! ;-)

ST

Hi,

it's available in germany for 0.52??? each.

BR,
Michael

-------- Original-Nachricht --------
Datum: Thu, 08 Feb 2007 07:50:38 -0000
Von: "m8jpk" <ttesenq@...>
An: TekScopes@...
CC:
Betreff: [TekScopes] Japnease Transistor

--
"Feel free" - 5 GB Mailbox, 50 FreeSMS/Monat ...
Jetzt GMX ProMail testen:

Hello all
are there any UK-based members out there with a Tek 2465?

As mentioned in a long post a couple of weeks ago I'm tryingto track
down a problem with mine. Currently my best bet is the Z-axis Hybrid
U950, p/n 155-0242-01. I will by a new one of those if need be, but
I'd like to be more sure of my diagnosis(*). If someone would be up
for trying my Hybrid in their 'scope and confirming that it is the
problem, I'd be very grateful. Postage etc. covered of course. Please
get in touch if you could help me with this.

Thanks
jon N

(*) I've checked the DC voltages on J119 which are all within limits
on a DMM, and the p-p ripple is fine on each voltage. The grid bias
adjustment alters the brightness fine, & it becomes apparent that the
front panel intensity control has *no* effect. The intensity control
does alter the output of the Display Sequencer Chip, but the waveform
#65 in the service manual (zBout from the hybrid) sits at around 3V
regardless of the position of the intensity control)

Heh.. cut teeth on a PDP-8 - we were first to use a "(mini)computer" to control the guide field of a large particle accelerator.
Here was this 'bitchin' lookin heavy/small Thing with smoked-plastic covers: blinking at you. In Octal.

The DEC "manual" was written for those who already knew what was in the manual. I had to start with a blackboard and Boolean Algebra book, on through RIM loader, wft-is-'assembly'?, wtf is an 'ALU', octal etc. I realized I'd never be (want to be) a programmer, but at least learned how-to: create a program to print out a BCD encoded paper tape on the ASR-33. Valuable lore.. from machine language through assy and compiling my source on the CDC-6600. And quite enough por moi, thankyouverymuch.

It's always useful to suffer through the basics.. then no snot-nose wannabe-someday 'IT'er can baffle you with BS.. 'explaining-away' some latest Redmond buffer overflow - built in by some bored committee of drones chained to a cubicle 10 years ago: and today -?- exposing you to the spoofer from Belgrade. Crapware has now infected the entire World. It will take a generation to undo what autistic/arrogant Billy has done to us all. For mere greed via mere hubris.

Still have a pristine Otrona??? CP/M portable w/ 5" green screen - operable last year I looked. Any takers?
(Word Star mnemonic codes inculcated into fingers.. still beats stupid-mousing distractions and M$ Word style eye candy -- for sheer speed of text entry -- for any touch typist. ^KS - saves your work, etc. You never forget, as their mnemonics made logical sense immediately - and your hands never left the home row.)

Fat chance of getting a 100 GB HD onto that CP/M OS, though :-/



Chuck Harris wrote:

Hello All
I am trying to source Some Japnese transistors or get some equivalent
info. ( 2SC2909)
Any help most welcome
M8JPK

im quite familiar with the lsi11 and q bus
never was a great fan of the data general nova machines.

They had nice features and some crocks. The 'increment memory location'
via DMA was useful for making multi-channel analyzers and photon
counting imagers. Their use of mostly standard parts was a real plus.
You could make good money by buying a minimally stuffed board and
loading it fully, once you knew how. The company management sucked, top
to bottom, with the sole exception of an ex-Tek sales engineer.

FWIW,
-John

Note that there are BNC adaptors on an extruded oval alloy shield which shrouds right down to the faceplate plane (at least hP sold these - probably others.) Wish I had a few more of these. With the shield physically connected to the black/common binding post, you have ..almost.. a fully shielded 'can'. Worked fine for the few-???V noise floors of the various sensitive good AC meters du jour.

(My lovely Racal-Dana 9300, good down to Boltzmann noise and to a phenomenal MHz top-end RMS, ~20 MHz at 6:1 crest IIRC? - natch was already BNC equipped.) Very handy with it's output amp sent to an accurate DC DVM, when you care about <0.1% relative levels.

Ergo "binding posts" need not be a huge handicap - anywhere near audio freq.

Ashton


J Forster wrote:

are those ever availible?
looks like alot better unit then a comparable hp 9825a
and the tek basic is fantastic for its day

For audio band distortions you just need what is called Wave Analyzer (in
other
words spectrum analyzer) in 5Hz -50kHz. I own one with some same spare - HP
analyzer for audio band.
Any scope is not capable to "see" small distortions....

Greg


At 04:14 PM 2/7/07 -0500, Kuba Ober wrote:

I was talking about "aligning" audio circuits, e.g. adjusting operating
points of various stages, checking response, etc. Not about any sort of
RF work.

If I wanted to see a nonlinearity of a stage in an audio power amp, for
example, it'd be nice to believe that the scope's vertical system is
linear enough, etc. Same goes for step response: hard to do with a scope
that may well distort even a perfect square wave.

Anyone who is at all capable of making those kind of measurements
would surely measure the input square wave first. If it looks like
a square wave, then the scope is good enough for the task.

The input will look like a square wave even with a badly nonlinear vertical
channel. The output "square" wave will then typically be much slower than

the

input one you fed to your system. With nonlinear vertical, the slower
transitions on the output square wave will look distorted, and you may

end up

chasing ghosts, especially if the audio amp alignment procedure mentions
e.g. "adjust Rxxx for output transitions to be smooth".

I just don't believe in using unchecked instruments, and a reasonable way

to

check a 7603 with plugins is to use the classic calibration trio in a

TM503,

plus a mainframe standardizer.

How on earth can anyone recommend using an unchecked, unknown scope to a

newb

is beyond me. Newbs tend to misunderstand limitations of instruments they
use, so they are very likely to just blindly trust the trace, even if

someone

experienced would check things twice first. You know, things like using too
much or too little of vertical deflection, not centering the signal and
hunting differing rising/falling edge aberrations, and so on. It's just

very

easy to hit those on an uncalibrated scope methinks.

Cheers, Kuba

Emacs!

because of modern technology
you aren't paying very much for all those modes
the software programming is amortized over a tremendous number
of units

True, but many (most) users REALLY don't want to have to read a 50+ page
manual to make a piece of toast or a cup of coffee. My reply was more
directed at "Why make it simple when complicated also works well"

How many of the VCRs you've seen over the last few years just sit and
blink 88:88:88 at you? Too many, IMO. I no longer bother to set mine
after a power fail.

-John

Everything from a wire wrapped 1802, low serial # Altair, early IMSI etc.

Most will still power up.

Hugh





arthurok_2000 wrote:

im quite familiar with the lsi11 and q bus
never was a great fan of the data general nova machines.

is anyone in this group other then dave wise
into old computers??

Yes, but not actively. Most of the Data General Nova line, but not
eclipses. Also some LSI 11s in the Tek DPO. Also Multibus and some VME.

-John