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Interesting... talking about electro-mechanical computer, I inherited some
modules I wonder if anybody can shed some light on them.

See the pictures (/g/TekScopes/album?id=257222)
Lots of resolvers and syncros inside. Looks very much aeronautic... maybe
something european, Tornado?

cheers
Martin

On Nov 27, 2020, at 2:48 PM, Siggi <siggi@...> wrote:

back

In addition, smartphones use Wi-Fi and other comms methods to navigate.
Much superior to those TomTom boxes that only used GPS.JimSent from my
Verizon, Samsung Galaxy smartphone
-------- Original message --------From: stevenhorii <sonodocsch@...>
Date: 11/27/20 3:54 PM (GMT-08:00) To: [email protected] Subject: Re:
[TekScopes] (OT) Where to go for 70s IBM hardware? I'm looking for a
terminal. Jim,Yep. I'm pretty sure the navigation system in my car uses GPS
primarily butmust have a dead reckoning system as it shows me where I am
when I amdriving through an underground tunnel. The system updates as soon
as theGPS signals are again available, so there are sometimes funny jumps
fromshowing me somewhere off the highway to back on it. GPS-aided
inertialseems to be the way many navigation systems are being designed.On
Fri, Nov 27, 2020 at 6:46 PM Jim Ford <james.ford@...> wrote:> FWIW
inertial navigation systems and GNSS (Global Navigation Satellite> Systems)
are complementary. INS tend to drift over time, and GNSS provide>
corrections. Navigation in GNSS-denied or -degraded areas is a whole
other> ballgame.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone>
-------- Original message --------From: stevenhorii <sonodocsch@...>>
Date: 11/27/20 1:04 PM (GMT-08:00) To: [email protected] Subject:
Re:> [TekScopes] (OT) Where to go for 70s IBM hardware? I'm looking for a>
terminal. Harvey and Bill,Yes - I've tried that trick. For small gyros it>
works. Gyros with electricspin motors tend to draw the most current at>
startup as do most motors.After that, the current usually drops quite a>
bit. Some of the 400Hz gyrosuse two-phase power. The usual trick is to put>
a capacitor across the twospin motor inputs - it provides the phase lag
for> the second phase. I haveNOT tried this, but I have seen some gyros ->
usually the small ones thatare about one-inch in diameter and three inches>
long and almost always rategyros - that had a phase-splitting capacitor>
already soldered in place.This white paper describes a basic 2-phase power>
supply for gyro spinmotors:>
>
was fortunate - at a hamfest years ago, I picked up a couple of>
AbbottTransistor Labs inverters. These took 24-28 VDC and output AC 400Hz>
singlephase at up to about 2 amps. Not enough to run a large gyro, but>
enough forthe smaller ones. I even ran a fairly large gyro - a Honeywell>
rate gyro -with one of these. They do need a heatsink.I sometimes do an>
eBay search for "Behlman Invertron" as they made somevery useful frequency>
converters - 115 VAC to variable 400Hz AC. Some werevariable frequency and>
some versions also had single to three-phase output.They tend to be>
expensive (and heavy for the higher output ones) and Inever managed to
find> one at what I thought was a reasonable price. Someversions had>
interchangeable plug-in oscillators so you could run evenhigher frequency>
AC devices (some gyros use 800 Hz - the Apollo programgyros ran with 800>
Hz, 2-phase power). There are currently a couple ofBehlman Invertrons on>
eBay, though they are not cheap.If you can find them, some of the WW II
and> even early missile (Nike) gyrosran on DC (24-28 v). Those are fun to
run> up. However, I've had some forwhich the bearings almost certainly were
bad> - they were very noisy whenrunning and spin-down after power was
removed> was quite fast. Likely whythey were surplus.Years ago, a surplus
dealer on> Canal Street in NYC sold me a WW II Bendixvertical gyro. It was
a 400Hz> gyro and he told me I could run it on 60Hz ACby putting a current
limiting> incandescent lamp (no choices - there were noLED lamps then) in
the power> circuit and running at a lower voltage via aVariac. I did not
have the guts> to try it, but I do know those who did andsaid it works, but
you will not> get the gyro up to full speed.Messing about with gyros can
lead you down a> deep hole much as gettingfascinated by Tektronix equipment
and then> desiring to get some (plusspares "for parts" and all the
manuals). Now you> can get fairly accurategyros made using IC fab
techniques - the MEMS units.> These things live insmart phones and tablets
now. These plus GPS have> radically changedinertial navigation. Fun stuff,
though.Steve H.On Fri, Nov> 27, 2020 at 1:52 PM Harvey White <
madyn@...> wrote:> Hi-fi> amplifier of sufficient output
capability driven by a sinewave> generator> sitting at 400 Hz?>> Harvey>>
On 11/27/2020 11:52 AM, Bill E wrote:> > Even> though way off the off topic
topic (parse that), still a fun> discussion. I> scored a box of 10 real
gyros and logic pulled from DC-10s.> Cute little> rate gyro, etc. Problem
is, all that stuff takes 28v 400Hz.> Haven't gotten> around to making a
power supply for them yet.> >> >> >> >> >> >>>> >>>>> >>>

Tim,

Your story reminded me of my first date with my wife (we'll celebrate 30
years in 2021). I took her to Vulcan Surplus (closed years ago) in
Stamford, CT. I lived in NYC the first time I went and later when I lived
in northern NJ. We went to United House Wrecking afterward - they were an
outfit that salvaged stuff from houses and other buildings being torn down.
Not much electronics, but acres of other stuff. Some of those things would
likely have been worth the "investment" - old wooden public telephone
booths for example. Besides the surplus electronics I found at Vulcan,
there was also their huge stock of hardware, most of it stainless steel.
You could buy stainless steel screws, washers, nuts, etc. by the pound.
They did charge more for the really small stuff - stainless screws in 0-80
to 2-56 - a box of 100 of these (in the original manufacturer boxes) was
$1-2. I have been to Fair Radio Sales - my in-laws live in Ohio near Dayton
- but only a couple of times. Other stuff I bought from their catalogs. I
knew my wife-to-be at the time was the right person for me - she's not an
engineer but she did work (until she retired) as a systems analyst and
software development team manager.

The sad bit is when surplus dealers go out of business and with no one to
take it over, stuff often goes to scrap dealers. I am pretty sure that this
is what happened to Omnibus Electronics on Long Island. Lou Lasser owned
the place and there was an associated business that did contract
electronics work. Lou bought a lot of stuff from the aerospace companies on
Long Island so it was like a candy store for me - I spent a lot of money
over the years on Apollo surplus from Grumman and Kollsman Instrument. I
still have boxes of small parts from the Apollo optical stuff. Sadly, four
Apollo Lunar Module Alignment Optical Telescopes got scrapped. Brand-new in
the NASA blue transit cases. I managed to get some of the eyepiece
assemblies and various spares, but no complete telescopes. Also scrapped
were three of the much more elaborate Apollo Command Module Optical Unit
Assemblies - they housed the sextant and telescope assemblies used for
updating the inertial navigation system. Lou claimed he told one of the
guys who scrapped stuff not to scrap the LM AOT and CM OUA, but the message
never got to the other guys and when Lou was out on a buying trip, the
person he told not to scrap the Apollo stuff was out making a delivery and
the other guys went after the Apollo stuff with hammers. They sold the
scrap beryllium for about $120 a pound. I saw (and bought) the remains of
these, so I don't doubt he had the complete units. The CM OUA had about 60
pounds of beryllium in it (actually, the whole casing was a large beryllium
piece). Lou had a second building he used for storage - he let my friend
and I look around, but he said the later Grumman stuff was in large crates
on pallet racks and getting them down would take too long. I did buy some
test equipment from him, but not much Tek stuff - a couple of letter and
1-series plug-ins. His prices for test equipment were a little too high. He
moved the business years later and my buddy and I went out there - also
still on Long Island. We both found interesting stuff and bought it. He
showed us several rows of truck trailers in his back lot full of all that
stuff that had been in the storage warehouse - so we still never got to see
it because it was late in the day by that time and getting into those
trailers would have been a difficult task. The next time we called him, the
number had been disconnected and we were told he had passed away. No one
could tell us who purchased the building and lot - my friend went by and
both were empty. We have no idea what happened to all that stuff. If there
was a lot of space program surplus from Grumman, it has not shown up on
eBay or in the space program auctions. It either went to scrap or someone
is hoarding it. If anyone on this thread had been to Omnibus or knew Lou
Lasser, I'd love to know more. Lou was a very nice guy and he always had
great stories about getting the surplus stuff he did acquire.

On Fri, Nov 27, 2020 at 8:21 PM Tim Laing <laingt@...> wrote:

Hello, I live about 2 miles from Fair radio. I know the owner Phil, not
a close friend though. I am not sure what will happen when he retires....
I do not know if the show room is open to the public at this time. I
can do some checking. I can stop in but if I do I generally need to have at
least 2 hours free to wander around and get my fix.... I have gone there
on missions for other people in the past. I could check on plug ins.
My first visit was probably when I was 13 or 14 years old, I am 59 now.
I took my future wife to Fair Radio on our first “date”. Maria and I
are still Married going on 31 years.
Prices are not cheap but he has a lot of overhead costs. I have a
bunch of pictures that I have taken there in the past, I am afraid of the
day I find out they are closing. I wish I had taken pictures in the old
dairy buildings located on Eureka Street. Tim Laing

Hello, I live about 2 miles from Fair radio. I know the owner Phil, not a
close friend though. I am not sure what will happen when he retires....
I do not know if the show room is open to the public at this time. I
can do some checking. I can stop in but if I do I generally need to have at
least 2 hours free to wander around and get my fix.... I have gone there
on missions for other people in the past. I could check on plug ins.
My first visit was probably when I was 13 or 14 years old, I am 59 now.
I took my future wife to Fair Radio on our first “date”. Maria and I
are still Married going on 31 years.
Prices are not cheap but he has a lot of overhead costs. I have a
bunch of pictures that I have taken there in the past, I am afraid of the
day I find out they are closing. I wish I had taken pictures in the old
dairy buildings located on Eureka Street. Tim Laing

Roy,

If you do any standard-definition TV (SDTV) work - such as converting older
videocassette or other SDTV recordings to DVD, both a waveform monitor and
vectorscope would be useful. A timebase corrector might also be helpful.
All of this stuff can now be obtained at relatively low cost. But I don't
know of non-SDTV uses for these items. It's too bad because they are great
instruments. I had a Tektronix 1900 and then a 1910 TV signal generator.
These had digital signal generation but converted to analog output for
driving monitors and the like for testing. Tektronix had quite a product
line to support the television industry. Tektronix equipment (along with
Grass Valley Group which Tektronix acquired) was likely in almost every TV
studio in the US. I think the huge 2" quad video machines came with a
Tektronix waveform monitor and vector monitor installed in them, at least
the vintage RCA and Ampex ones I have seen did.

There must be some collectors or users of SDTV stuff out there. I have seen
prices of the old Sony U-Matic machines (the studio ones) sell for higher
prices than one would expect (the broadcast version of the Sony U-Matic
machine - the BVU-950 - sells for over $2000). Even the Sony BVH-3100
one-inch C-format machines sell for over $1000 (on eBay) and shipping for
these things would be a quarter to half of that cost.

Steve H.

On Fri, Nov 27, 2020 at 3:19 PM Roy Thistle <roy.thistle@...>
wrote:

Hi All:
I am getting one.
My question is... what do I (What can I) do with it?...I know it is/was
intended for monitoring the NTSC television broadcast signal.
I do have a pdf of the user/service manual.

Hello, I live about 2 miles from Fair radio. I know the owner Phil, not a
close friend though. I am not sure what will happen when he retires....
I do not know if the show room is open to the public at this time. I
can do some checking. I can stop in but if I do I generally need to have at
least 2 hours free to wander around and get my fix.... I have gone there
on missions for other people in the past. I could check on plug ins.
My first visit was probably when I was 13 or 14 years old, I am 59 now.
I took my future wife to Fair Radio on our first “date”. Maria and I
are still Married going on 31 years.
Prices are not cheap but he has a lot of overhead costs. I have a
bunch of pictures that I have taken there in the past, I am afraid of the
day I find out they are closing. I wish I had taken pictures in the old
dairy buildings located on Eureka Street. Tim Laing

I just took a quick look at the 528 on tekwiki. As it is, it's pretty much only good for the original purpose. But, it appears to have an electrostatic deflection CRT (since it's basically a scope, not a TV display, which would tend to use raster-scan), so you could convert it to a nice little low speed X-Y monitor, with simple changes to the guts, if you're so inclined, and need such a thing. I don't know if the graticule is built into the CRT face (probably) - if so, you'd be stuck with the IRE etc scales, instead of a nice grid. If you really want to fix and make it into an X-Y monitor, you can probably find some Tek scope or other CRT that is the same except for the faceplate, and swap it in.

Ed

On 27Nov, 2020, at 6:21 PM, Tim Laing <laingt@...> wrote:

Hello, I live about 2 miles from Fair radio.? I know the owner Phil, not a close friend though. I am not sure what will happen when he retires....
? ? I do not know if the show room is open to the public at this time. I can do some checking. I can stop in but if I do I generally need to have at least 2 hours free to wander around and get my fix....? I have gone there on missions for other people in the past. I could check on plug ins.
My first visit was probably when I was 13 or 14 years old, I am 59 now.
? I took my future wife to Fair Radio on our first “date”.? Maria and I are still Married going on 31 years.
? ? Prices are not cheap but he has a lot of overhead costs. I have a bunch of pictures that I have taken there in the past, I am afraid of the day I find out they are closing. I wish I had taken pictures in the old dairy buildings located on Eureka Street.? Tim Laing

On 27Nov, 2020, at 6:21 PM, Tim Laing <laingt@...> wrote:

Hello, I live about 2 miles from Fair radio. I know the owner Phil, not a close friend though. I am not sure what will happen when he retires....
I do not know if the show room is open to the public at this time. I can do some checking. I can stop in but if I do I generally need to have at least 2 hours free to wander around and get my fix.... I have gone there on missions for other people in the past. I could check on plug ins.
My first visit was probably when I was 13 or 14 years old, I am 59 now.
I took my future wife to Fair Radio on our first “date”. Maria and I are still Married going on 31 years.
Prices are not cheap but he has a lot of overhead costs. I have a bunch of pictures that I have taken there in the past, I am afraid of the day I find out they are closing. I wish I had taken pictures in the old dairy buildings located on Eureka Street. Tim Laing

Hi All:
I am getting one.
My question is... what do I (What can I) do with it?...I know it is/was intended for monitoring the NTSC television broadcast signal.
I do have a pdf of the user/service manual.

On Nov 27, 2020, at 14:50, Dennis Tillman W7pF <dennis@...> wrote:

?There is another explanation for doing something like this which is not as obvious.
If you look at the schematic for the 067-0681-01 Tunnel Diode Pulse Generator designed by John Addis at Tektronix


There are three 1/8W 1Kohm resistors (R4, R5, and R6) connected in series going to the tunnel diode. Several years ago I asked him why he did not use one 3Kohm resistor instead. What he knew and I learned was that the body capacitance of each of these 3 resistors in series was far less than the body capacitance of one 3Kohm resistor. The TD is being driven by the collector of the transistor which is high impedance, and the three 1Kohm resistors in series reduces the time constant of the pulse going to the Tunnel Diode without adding any additional capacitance across the Tunnel Diode that would slow it down.

I doubt this had anything to do with Tek portable scopes since their frequency response is almost two orders of magnitude slower than the fast edge of the Tunnel Diode Pulse Generator but sometimes there are other explanations for why you might encounter things that are not obvious.

Dennis Tillman W7pF


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Milan Trcka
Sent: Tuesday, November 24, 2020 9:09 PM
To: [email protected]
Subject: Re: [TekScopes] Resistor in series

Jeff, the resistors connected end to end are an attempt to make a required resistance that was not available as a standard resistor value. Shortage of parts? Engineering change? Select in test? Who knows. I have a few of those in my 453 scope.







--
Dennis Tillman W7pF
TekScopes Moderator