Date   

Re: Tektronix scope issues

 

On Sat, Nov 28, 2020 at 07:07 AM, Thomas Dodge wrote:


I also have a Tektronix 7704 which I just powered on. I got it from a friend,
and when it is on, it just shows a beam that is very bright, so I turn it off
so it doesn't burn the CRT. The switches for the Time Base and the Volts per
Division have no effect.
Often, an uncontrollable, very bright CRT image indicates a problem in the DC restorer circuits.
If combined with absence of vertical and horizontal deflection, it most often indicates a problem in the (low-voltage) power supply (LVPS), which may also affect Z-axis behavior, causing a high intensity beam.
Fault finding may not be too difficult but you must protect the CRT - and yourself. Since I have no idea what level of experience yo have, I have to warn you WRT the dangers involved in working on these instruments. No intention to insult you...
With deflection absent, you can't move the beam off-screen to protect the CRT, so at least turn focus to either completely CW or completely CCW. That's probably not enough to protect the CRT (burning), neither will be removing the post-deflection acceleration (PDA) voltage (red wire to front of CRT).
Be very careful with the high voltages present and don't forget that the PDA voltage may take hours (or more) to bleed away - and that the 6.3 Vac filament supply is floating at about - 3 kVdc...
Once you've excluded the LVPS as the cause of your problem (a good chance the problem lies there), it would be very informative to see if there's a negative voltage between cathode and grid of the CRT: The CRT's grid should be at least 50 volts or so negative (averaged DC) with regard to the cathode with intensity turned down all the way. If the voltage is very low, intensity will be max. Measure using a battery-supplied high-impedance (>= 1 MOhm) voltmeter, well-insulated, and placed at least 5 cm away from any conductive areas. Connect first, then power on!

But first you need to protect the CRT's screen from being burnt. To achieve that, you have several options but you need to know what you're doing. Examples in decreasing order of my preference are:
- Temporarily disconnecting the filament supply (6.3 Vac).
- Temporarily removing the CRT. A bit dangerous, not as difficult as it may seem but not attractive until experienced...
- Temporarily stopping the inverter producing filament- and high voltage. This would take away the possibility to (among other things) measure grid-cathode voltage though and therefore in my opinion be the least attractive option.

Raymond


Re: Horizontal Display switch shenanigans.

Dave Peterson
 

It was late, my brain wasn't firing on all cylinders. 2mm? Really Dave? They seemed thicker than 1mm, but I just went and measured: 1mm. So there ya go, exactly 1mm.

How have you guys removed this assembly? Solder wick? Heat gun? The board seems a robust big component kind of thing that a heat gun would work on. No surface mount Rs & Cs to float off. I've never actually done a hot air dismount before, so any ideas/suggestions are appreciated.

Dave


Re: Horizontal Display switch shenanigans.

Renée
 

I have actually completely disassembled and swapped bits and pieces of switches ( and other mechanical items) when unable to find what I want. the only time I could not effect a repair is when the assembly is molded . and at that although there are times that is even possible depending on how inventive and how much time ya wants to spend. you have very little to loose if it is already broke, take your time being careful is the motto....if it was mechanically assembled it can be re-worked. If man made it....
Renée

On 11/27/20 10:01 PM, Dave Peterson via groups.io wrote:
While pulling apart this 465 parts scope I tried removing the pushrods from the Horizontal Display switch on the A7 board. Working on the bottom "B DLY'D" pushrod the push button came out of the switch. I thought at first that it must be a simple mechanical assembly thing that I could put back together. When I had the chance to study it I realized that the plastic of the button had broken. I thought I must have done it trying to take the pushrod off, but then I noticed that the internal plastic button narrows to a very small "T" cross section. See the pictures in:

https://groups.io/g/TekScopes/album?id=257214

Notice the dirtiness of the cross section at the break. If the button was intact before I tried taking the pushrod off it must have been just by the top of the "T" and taken very little force to break it. I suspect it was already broken actually, and that having the board out of the scope allowed the pushrod to rotate down so that the button could come out of the switch assembly. When held horizontal the notches in the button catch on the ratchet mechanism of the switch, holding it in. When it rotated down it just came out with no force, nor did it make any noise. It just kind of fell out in my hand.

The back of the plastic internal button when complete has two channels that hold the metal spring contacts, which slide between the switch posts. I don't know if that's clear in the pictures or not. The point being, if this back piece with the contacts breaks off it ends up inevitably in the back of the switch. In the depressed position. I never turned this scope on - it wouldn't have worked with C1419 shorted anyway. I also didn't capture the back of the switch in any pictures nor notice if the button was visible from the back. They are when in the depressed position. So it's kind of lucky that I found this. If I'd tried the scope it would probably would be stuck in B DLY'D, or something worse with B DLY'D selected and whichever of the other buttons in the HORIZ DISPLAY group would be depressed. It's a pretty devious failure mode, and I have to wonder how common it is, given the fragility of that cross section.

Anyone else with experience with this kind of pushbutton failure?

But wait, there's more!

After finding this broken switch I looked it up by the Tektronix part number from the service manual I have - Fig 2 Circuit Boards, item 124: 260-1423-00, "SWITCH, pushbutton--HORIZ DISPLAY". I found a NOS listing from a company called "Talon Electronics LLC". I ordered it, but was surprised to find on my order after a day some notes from someone in the shipping department which read "cut pin", and submitted a refund for me. But then also shipped it anyway noting "might work in his application". Aw! How nice of them!

So the part came the other day. I unpacked it and compared to my A7/switch. Look at the last two pictures in the above album. Sure enough there's a "cut" pin, but note there's also a cut pin on the existing B DLY'D switch. But look closer: the new part has the wrong pin cut! The new switch in the picture is "on its back". It would be flipped over putting the cut pin at the front side of the board, not the back! Ahg! At least I got a refund. How the heck did this NOS part get in the system in the first place!? Bo-bo in the manufacturing process? Someone had too much to drink the night before and cut a whole batch of switches with the wrong leg cut?

So now what? I'm thinking what I'll do is cut the rearward pin of the new B DLY'd switch, and then cut the existing switch forward pin leaving it soldered into the board. Then when I mount the new switch I'll solder the new switch cut pin to the existing post from the old switch? Maybe place a piece of lead along the post and solder that?

Any other ideas or suggestions for this? I do see another one on eBay, but used. So no assurance that it's in good working order.

But what a convoluted situation! I wanted to share the failure of the switch. It seems like a hidden failure that someone might benefit from the experience. I'd also love to hear any ideas for "fixing" the new switch. Or should I just buy the used one on eBay?

Dave




Re: Horizontal Display switch shenanigans.

Dave Peterson
 

Thanks Raymond. I was wondering about that.

Do you just pull the lead out of the switch with some pliers? I imagine one needs to be careful about the switch position, or the switch contacts re-inserting? I figured I'd give this a try when I have the old one out. Not try it on the new on.

Parts are arriving, so busy on many fronts!
Dave


Re: Fair Radio Sales Lima Ohio

garp66
 

Surplus, of course, has been the best place to get stuff for repairs, ... but further, to leap ahead for invent.

University research labs on small budgets, high school students just getting started, and small companies all able to take advantage
of Obso, over-run, or cancelled project debris. No matter where, from Boston/MIT, Harvard; Eli Hefferon & sons, or the many in New Hampshire, and many more down the coast to Florida, due to the Cape; Dayton forever(lets hope), the many in the midwestern states and the huge surplus warehouses in silicon valley & up the coast to Boeing surplus sales, and beyond (Hello Walter !).

One could spend a lifetime wandering through them and most assured able to find treasures of yesteryear, "... ah ha, that's how they did it".
fortunes were spent on the design, engineering and construction of a part, let alone systems, materials and processes that wandered off to surplus floors, and then to the high temperature kilns or landfills of history. We do not even know what we have lost, and the old timers who knew that something of value still remained.

It is a hard day indeed when that source dries up...
While barely detailed in "The Hackers", ...at least the surplus "concept" was mentioned.
There are details of technological history in the remnants that might never be comprehended.

Curiously, Surplus junk yards are often a short-stop in movies such as the various Star Trek's( even in Discovery, etc.), Star Wars, & so on...

May they ever be there for us & those that follow, for the future.


Re: Horizontal Display switch shenanigans.

 

On Sat, Nov 28, 2020 at 07:01 AM, Dave Peterson wrote:


Any other ideas or suggestions for this?
With these "radio button" sets, it's often possible to just replace one stem, without much disassembly nor removal of the set. You'd need to move the interlocking-bar and spring out of the way first though.

Raymond


Re: Fair Radio Sales Lima Ohio

saipan59 (Pete)
 

On Fri, Nov 27, 2020 at 09:12 PM, ken chalfant wrote:


I live in Colorado Springs, Colorado. There has been a “surplus”
electronics store here for 34 years
Hi Ken,
I'm here in C.S. also, and shopped at OEM many times since the 80's. I worked at DEC, as did Dick's "employee/partner" Robert.
I'm curious what you plan to do with all the semiconductors you bought?

Pete


Re: Tektronix 7D13 and 7A42 wanted

Dave Daniel
 

I've just started to remove the battery from my 7A42.

I see the usual exploded parts diagram in the manual, but I don't see instructions anywhere for removing the PWBs. It looks as if one has to completely remove the rear panel (-124 in the exploded view) in order to pull the A8 board out. Is this the case, or am I missing something? Any pointers would be appreciated.

Thanks

DaveD

On 11/18/2020 11:58 PM, Dennis Tillman W7pF wrote:
Hi Ed and Dan,
I'll toss the battery and remove the jumper in mine also.
Dennis

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Ed Breya via groups.io
Sent: Wednesday, November 18, 2020 7:14 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix 7D13 and 7A42 wanted

Hi Dennis,

I didn't realize earlier your question "What did you use for a battery?" was to me. There is no battery. For something like this, it's simple enough to set up as needed, for occasional use. Having it remember is a nice convenience, but not worth the trouble and leakage risk. All I did was check it out after enough burn-in, and I removed the BE jumper as Dan suggested. It's running right now for one last time before mothballing.

Ed






--
This email has been checked for viruses by Avast antivirus software.
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Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

stevenhorii
 

To me, they look like modules from an air data computer. Before the digital
ones, they had modules like this. There were modules that had a
bellows-type assembly for the airspeed (pitot tube) input as well as the
servos and resolvers to compute values for the cockpit gauges. Do an image
search for “F4 Air data computer”. The MOD could either be “modifications”
or “Ministry of Defense”. I suspect “modifications” as the tags often look
like the one on that module cover.

Better yet, go to Glenn’s Computer Museum (glennsmuseum.com) and click on
the “Old Military” section (note: lots of photos - takes a while to open).

There’s an amazing amount of stuff in his museum besides computing stuff.

He’s another potential source for older IBM equipment. He might be open to
swapping stuff as well.

Steve H.


and look at the “Old Military

On Sat, Nov 28, 2020 at 04:26 Martin <musaeum@arcor.de> wrote:

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

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

cheers
Martin







5 photos uploaded #photo-notice

TekScopes@groups.io Notification <noreply@...>
 


Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

 

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

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

cheers
Martin


Re: Horizontal Display switch shenanigans.

Dave Peterson
 

I don't have it out of the board yet, but I could measure the new one. They're thick - like 2mm? I'd have to measure, and I'm shutting down for the day. Thanks for the offer. I'll look at it tomorrow.
Dave


Re: Horizontal Display switch shenanigans.

adesilva_1999@...
 

Now that you have it out of the board, what is the size of the pin? Like I said, I can send a couple of them in the mail.


Re: Horizontal Display switch shenanigans.

Dave Peterson
 

Ooo. Thanks for that! Not only does that make for a viable solution, I've been wondering about a suggestion from an EEVBlog thread in which someone replaced soldered wire connections with connectors. These would work for that too perhaps. The bigger lead here is thinking about going Mouser for such construction solutions. I'm learning.

Thanks for the tip!Dave

On Friday, November 27, 2020, 11:00:39 PM PST, adesilva_1999 via groups.io <adesilva_1999=yahoo.com@groups.io> wrote:

Hi Dave,
Check this: https://www.mouser.com/ProductDetail/TE-Connectivity/510-AG90D-10?qs=%2Fha2pyFaduhM4gHyZk8iA5%252BbCzoO6EXmbo0JD0Y5IKbJxRi4JyNZJA%3D%3D

You can get something like this and break off just one pin and solder in place. Depending on the diameter of the pin on the switch, It might mate with the open end. If you need to test it out, I can send a couple of the to you.

One other method is to wrap around a similar diameter copper wire (single strand) and solder it close to the bottom of the switch leg. and slightly bend it to go in the PCB hole. I will PM you if you want to talk.

Ananda


Re: There is no good time to be SICK

Glydeck
 

Dennis,

Be well. Thanks for all you do for this group.

Kindest regards,

George

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

back


Re: Horizontal Display switch shenanigans.

adesilva_1999@...
 

Hi Dave,
Check this: https://www.mouser.com/ProductDetail/TE-Connectivity/510-AG90D-10?qs=%2Fha2pyFaduhM4gHyZk8iA5%252BbCzoO6EXmbo0JD0Y5IKbJxRi4JyNZJA%3D%3D

You can get something like this and break off just one pin and solder in place. Depending on the diameter of the pin on the switch, It might mate with the open end. If you need to test it out, I can send a couple of the to you.

One other method is to wrap around a similar diameter copper wire (single strand) and solder it close to the bottom of the switch leg. and slightly bend it to go in the PCB hole. I will PM you if you want to talk.

Ananda


Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

stevenhorii
 

Yeah, I think smartphones can also triangulate off of cell towers. I have
had the experience with my in-car GPS of driving in a new housing
development that was likely not in the map database the car had. It showed
me in the middle of a field. My funniest experience with GPS was when I
returned from a trip to Berlin. I was trying to use what is really an
automotive GPS for walking around the city. I had loaded my location and it
showed it correctly on the map, but it would simply not update correctly
when I was walking around the city. I put the unit away until I got home.
The next time I used it, I took it with me from where I was living in
Maryland to Los Angeles on a flight. I turned it on for the first time
since using it in Berlin and when I put in my uncle's address in LA and it
spent a LOT of time calculating the directions. It came up with "drive 5400
miles east to I-405 South" as the first direction. I then had it reset to
the local position (I must have told it to use my last known destination as
the start) to get the right directions. I got a laugh out of that.

On Fri, Nov 27, 2020 at 8:41 PM Jim Ford <james.ford@cox.net> wrote:

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@gmail.com>
Date: 11/27/20 3:54 PM (GMT-08:00) To: TekScopes@groups.io 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@cox.net> 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@gmail.com>>
Date: 11/27/20 1:04 PM (GMT-08:00) To: TekScopes@groups.io 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:>
http://usdynamicscorp.com/literature/general/AN-003%20USD%20Spin%20Motor%20Excitation.pdfI>
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@dragonworks.info> 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.> >> >> >> >> >> >>>> >>>>> >>>





Re: Fair Radio Sales Lima Ohio

stevenhorii
 

All these stories about surplus made me wonder - is there a group dedicated
to surplus? The stories are usually great ones.

Steve H.

On Sat, Nov 28, 2020 at 1:22 AM Steven Horii <sonodocsch@gmail.com> wrote:

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@wcoil.com> 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






Re: Fair Radio Sales Lima Ohio

stevenhorii
 

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@wcoil.com> 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






Tektronix scope issues

Thomas Dodge
 

Hi,
This is Tom Dodge, and I am posting this topic again because I didn't post it right before. I have three Tektronix scopes. I have a Tektronix 533 that doesn't work. When I turn it on, it does not have a trace at all, and just a beam. I also have a Tektronix 7704 which I just powered on. I got it from a friend, and when it is on, it just shows a beam that is very bright, so I turn it off so it doesn't burn the CRT. The switches for the Time Base and the Volts per Division have no effect. I also have a Tektronix 684A which shows the most promise. I bought it from a surplus place, and is in very good condition. When I took it home and powered it on, it didn't come on at first, but after a few more tries, it did power on and went through the Self Test process, and it seemed to be ok. When I turned it off and on again, it worked ok. When I powered it on the other day, panel lights came on, but the CRT did not. I even tried to connect an external monitor using the VGA output ii the back, and I didn't get any signal. I remember reading somewhere about this issue, and the solution was to replace a chip on the board, but I can't verify that. I did look at the manual to see what it said if the self test doesn't work, but I didn't see anything. Does anyone have any ideas about this? Thanks.

Thomas Dodge

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