Date   

Lots of fresh goodies being uploaded for spring stuff season

 

We have been finding all kinds of strange and bizarre items in storage here at Sphere, from
unknown optical widgets and hard to find parts to 10KVDC power supplies. Plus, we keep filling
up the Free Stuff section with nice finds, you are sure to see something you like.

to see the 10KV supplies, go to: https://www.sphere.bc.ca/test/stuffday.html#power2

if you have time over the weekend, drop by and have a look at all the interesting items:
main gateway: https://www.sphere.bc.ca/test/stuffday.html
Tek stuff: https://www.sphere.bc.ca/test/stuffday.html#tekfans
R+D magical items: https://www.sphere.bc.ca/test/stuffday.html#rdmagic
HP stuff: https://www.sphere.bc.ca/test/stuffday.html#hpfans
Free Stuff: https://www.sphere.bc.ca/test/stuffday.html#free

an of course, at the bottom is the big clear out of CRTs:
https://www.sphere.bc.ca/test/stuffday.html#catalog

Boy, could we use all that room back!
all the best, stay safe,

walter (walter2 -at- sphere.bc.ca
sphere research corp.
https://www.sphere.bc.ca/test/index.html


Re: Maybe lots of tek scopes and plug-ins for sale

Tony <tony@...>
 

Well, that was fast! Everything is gone, so if I haven't reached out personally, I hope you see this post.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Tony
Sent: Thursday, April 15, 2021 3:01 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale

Hi Dennis,



A couple bay area guys reached out directly, and they have this info now, but I'm also posting it here for everyone else to see.



http://encoreelectronics.com/tek/



I think a larger majority of it works, and I know the price is dependent on the working status. I was thinking people could make offers based on 80% of everything working, and then we could reduce it from there if we discover more failures that that. I'm not looking to take advantage of anyone, but I also want the same consideration. The more convenient someone can make this for me, the lower the price they'll pay. 😊



Thanks,

Tony





-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dennis Tillman W7pF
Sent: Tuesday, April 13, 2021 5:49 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale



Hi Tony,

This is a chicken and egg situation. You want to know how much interest there might be but that would depend on what you have to sell and what you are asking for it. Likewise this might be the right place for it if there is enough interest in your inventory, its condition, and the proposed price. Any other place will want to know the same things so you have to make the first move and prepare an inventory list of equipment and its condition (working or not, etc).

Dennis Tillman W7pF



-----Original Message-----

From: <mailto:TekScopes@groups.io> TekScopes@groups.io [ <mailto:TekScopes@groups.io> mailto:TekScopes@groups.io] On Behalf Of Tony

Sent: Tuesday, April 13, 2021 5:03 PM

To: <mailto:TekScopes@groups.io> TekScopes@groups.io

Subject: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale



Hello all,



I've been watching this group on and off for a long time, and have finally come around to the reality that I have too much stuff and will likely sell it all to free up space. There are a few mainframe chassis, and maybe 40 or 50 modules and a couple carts. I would rather NOT ship it anywhere, so I'm wonder if someone in Northern California would be interested in it as a group purchase? Of course I will have to inventory it all, but I wanted to see if anyone could point me to an appropriate place to sell this?



Thanks,

Tony

















--

Dennis Tillman W7pF

TekScopes Moderator


Re: OT: FFTP: Triplett Model 630-APL VOM with Corrosion

Gordon Smith
 

I have enough reply's/offers that I can say the VOM is spoken for.

Thank you, Gordon


Re: Sony/Tek 380

Doug
 

In my case the CRT is working in that the screen is lighting up but it looks more like a flooded storage tube.
The entire screen is glowing and I can't change the brightness, let alone get a dot or a line.


Re: 2101 Pulse gen repair report

Tom Lee
 

Hi Michael,

I expect the same transistors to be good subs for the actual output amp, too, so if the thing blows again, I'd give those a try. I don't know what Tek sorted for, but a (very) crude proxy for ft is 1/BVCBO. Lower breakdown voltage is correlated with higher ft. So if you find the risetime to be marginal, that's one sort you can perform to identify the most promising candidates (assuming you have, or have access to, a curve tracer).

And the 2N918 family includes a great many different part numbers (the 2N918 is sort of the 2N3904 of ~1GHz transistors). Even though through-hole parts are obsolete (or at least obsolescent), I've never had difficulty finding hobbyist-level quantities of devices in that family. Most recently, I bought a handful of 2N5770s from our own Brad Thompson. Those transistors are part of the 918 family. That part, as well as the PNP complement (2N5771), are good to keep in the junk box.

Cheers,
Tom



Sent from an iThing, so please forgive the typos and brevity

On Apr 16, 2021, at 4:39, "Michael Dunn" <md@cantares.on.ca> wrote:

Thanks Tom, tho, a few notes:

On Fri, Apr 16, 2021 at 05:17 AM, Tom Lee wrote:
For the output amp, the NPNs are 2N3053 and the PNPs are 2N4036, replaceable
here by the venerable 2N2219A and 2N2905, respectively. Those parts are still
available cheaply.
Those parts are for baseline offset, not output amps per se. No AC requirements, so, yes, fairly easily subbed.

To "fix" the output amp, I just removed the offending transistor of the paralleled pair. The remaining part will be fine, as long as I don't push the output too hard.


Q182 is a 2N3563, replaceable by several devices in the 2N918/PN918/2N2857
family.
Which seem to be obsolete, or close enough to :-( At least here, a modern/available SMD could be kluged in if need be. I did find a suitable old part in my junk box (2N5179), though its DC specs may be marginal. I hope it lasts.


Be thankful that it's a 25MHz gen, rather than, say, a 100MHz one. You should
be able to find replacement transistors to keep it going pretty much forever.




Re: OT: microscope source?

Brad Thompson
 

Hello--

My heartfelt thanks go to everyone who commented on my request
for microscope information. Per the moderator's request, please send
further comments directly to me at...

brad.thompsonaa1ip@gmail.com

The breadth and depth of collected knowledge in this group is
truly remarkable!

Thanks again, and 73--

Brad  AA1IP


Re: 465 Missing a Few Components

Stephen
 

A little follow-up on the restoration of this scope.
I’ve taken some time off from my current 2 restoration/repair projects to clear my mind a bit and do other stuff.

To recap the order of events: I had a short to ground on the 15V rail, which I discovered before powering the unit, and I had resolved this issue. That was cause by C891 being shorted (A&B Trigger Generator). L891 looked burnt and damaged, but is surprisingly reading good.
When I powered up the unit, the mains fuse blew instantly. Also, after that happened, the short to ground has come back on the 15V rail. This time it’s not C891. And I can’t seem to locate the cause.
Something else happened as well. I discovered a new short, but this time on the -8 V rail.

Regarding the mains fuse blowing, I found CR1541 to be bad, and replaced it. I also replaced all the filter caps.
As far as the short of the the -8V rail, it was due to a bad contact on the A Trigger pot. That wasn’t easy to find, as it was intermittent.

Now, if nothing else pops up, I’m left with finding where this new short on the 15V rail comes from, and I should be home free.

I’ve tested as many things as I could so far with no success.

Any lead will be most welcomed and appreciated.


OT: FFTP: Triplett Model 630-APL VOM with Corrosion

Gordon Smith
 

Hi All,
I have a beaten, battered Triplett Model 630-APL VOM that is free for the postage. It has corrosion in it that I cleaned out a bit, but the corrosion has dripped onto some of the measurement resistors so I would not classify this one as being fixable. Every case part has some crack on it, the face is cracked. The knob moves freely and the meter movement appears functional. Free to anyone who wants it, just pay the postage. Pictures are available, just send me an email requesting them.

Please reply via Private Message if interested or if you would like more info.

Thank You, Gordon (in San Diego)


Re: RF noise on ground

Roy Thistle
 

On Mon, Apr 12, 2021 at 10:13 PM, Dave Peterson wrote:


I guess the entire local grid is carrying energy from the tower.
There's lots of signals on the distribution lines... some intentional and others by accident.
I asked a broadcast engineer (worked on building several large AM and FM stations) and he seemed doubtful that you could sufficiently reduce the FM broadcast noise at your location. (But simple fixes, for desperate corporations are big moneymakers for these guys... so I took his viewpoint with a few grains of salt.)
I don't know if the Feds would get involved... or it your electrical utility company is responsible for keeping noise from being transmitted by their lines... or even if you could complain to the engineer(s) at KOIT. Likely as not, big money and politics are not going to listen.

--
Roy Thistle


Re: OT: microscope source?

Dave Wright
 

Ok, some info I have not seen mentioned...

The Stereozoom heads are affordable on eBay, but the stands and focusers drive the cost up.

I use a cheap 'monitor arm' to support a Stereozoom 4, and find that it works quite well for getting over the top of the equipment and peering inside. It might even work without the focuser at low zoom, as I find myself moving the arm for initial focus, rather than using the focus knob.

_Dave KC6UPS


Re: Sony/Tek 380

Steven Bender
 

Hi Doug,

I also have a Sony/Tek 380 that shows no trace, I bought it as a cheap parts donor for my likewise no trace 335 and 336. Somewhere, someone recall mentioned his 335 having blown a Fuji 2SC3030 Darlington 900 Volt transistor in a flat TO-3P case. So, I bought a bunch of those on eBay recently its such a high voltage unit, the gain is only rated at 9! Testing one of the bunch, my little Chinese Tester said its gain was five (5). I guess, close enuf. Not sure if this part is a known failure mode in these no trace Sony/Tek 300 series sets, been to busy to attend to repairs on these units.

Hope that tidbit helps!


Steven L. Bender


Re: 2101 Pulse gen repair report

Michael Dunn
 
Edited

Thanks Tom, tho, a few notes:

On Fri, Apr 16, 2021 at 05:17 AM, Tom Lee wrote:
For the output amp, the NPNs are 2N3053 and the PNPs are 2N4036, replaceable
here by the venerable 2N2219A and 2N2905, respectively. Those parts are still
available cheaply.
Those parts are for baseline offset, not output amps per se. No AC requirements, so, yes, fairly easily subbed.

To "fix" the output amp, I just removed the offending transistor of the paralleled pair. The remaining part will be fine, as long as I don't push the output too hard.


Q182 is a 2N3563, replaceable by several devices in the 2N918/PN918/2N2857
family.
Which seem to be obsolete, or close enough to :-( At least here, a modern/available SMD could be kluged in if need be (even so, finding one with suitable DC spex may be tricky). I did find a suitable old part in my junk box (2N5179), though its DC specs may be marginal. I hope it lasts.


Be thankful that it's a 25MHz gen, rather than, say, a 100MHz one. You should
be able to find replacement transistors to keep it going pretty much forever.


Re: Maybe lots of tek scopes and plug-ins for sale

Miguel Work
 

Where are they located?

Do you have any contact information?

I´m interested is some stuff

-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de Tony
Enviado el: viernes, 16 de abril de 2021 0:01
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale

Hi Dennis,



A couple bay area guys reached out directly, and they have this info now, but I'm also posting it here for everyone else to see.



http://encoreelectronics.com/tek/



I think a larger majority of it works, and I know the price is dependent on the working status. I was thinking people could make offers based on 80% of everything working, and then we could reduce it from there if we discover more failures that that. I'm not looking to take advantage of anyone, but I also want the same consideration. The more convenient someone can make this for me, the lower the price they'll pay. 😊



Thanks,

Tony

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Dennis Tillman W7pF
Sent: Tuesday, April 13, 2021 5:49 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale



Hi Tony,

This is a chicken and egg situation. You want to know how much interest there might be but that would depend on what you have to sell and what you are asking for it. Likewise this might be the right place for it if there is enough interest in your inventory, its condition, and the proposed price. Any other place will want to know the same things so you have to make the first move and prepare an inventory list of equipment and its condition (working or not, etc).

Dennis Tillman W7pF



-----Original Message-----

From: <mailto:TekScopes@groups.io> TekScopes@groups.io [ <mailto:TekScopes@groups.io> mailto:TekScopes@groups.io] On Behalf Of Tony

Sent: Tuesday, April 13, 2021 5:03 PM

To: <mailto:TekScopes@groups.io> TekScopes@groups.io

Subject: Re: [TekScopes] Maybe lots of tek scopes and plug-ins for sale



Hello all,



I've been watching this group on and off for a long time, and have finally come around to the reality that I have too much stuff and will likely sell it all to free up space. There are a few mainframe chassis, and maybe 40 or 50 modules and a couple carts. I would rather NOT ship it anywhere, so I'm wonder if someone in Northern California would be interested in it as a group purchase? Of course I will have to inventory it all, but I wanted to see if anyone could point me to an appropriate place to sell this?



Thanks,

Tony

















--

Dennis Tillman W7pF

TekScopes Moderator


Ghost spot on a 2445 sreen

f5dog
 

Hi.
This topic again about a strange thing on the screen of a 2445.
A ghost, not focused spot flashes randomly at a stable location on the screen, whatever the brightness setup, vertical scaling, tme base, triggering, etc...
When the scope is turned off, this spot remains visible during about one minute, before disapearing. A possible source could be a default regarding not enough screening from high voltage area, or a leakage problem, considering discharging capacitor time as an information to investigate the root cause of this ghost spot near the middle of the screen.
Waiting for any help or advice, if any idea or known problem.
Thanks and regards.
John.


Re: 2101 Pulse gen repair report

Tom Lee
 

For the output amp, the NPNs are 2N3053 and the PNPs are 2N4036, replaceable here by the venerable 2N2219A and 2N2905, respectively. Those parts are still available cheaply.

Q182 is a 2N3563, replaceable by several devices in the 2N918/PN918/2N2857 family.

Be thankful that it's a 25MHz gen, rather than, say, a 100MHz one. You should be able to find replacement transistors to keep it going pretty much forever.

Cheers,
Tom


Sent from an iThing, so please forgive the typos and brevity

On Feb 3, 2021, at 11:16, "Michael Dunn" <md@cantares.on.ca> wrote:

Well, I might be a bit rusty, but it seems I can still repair things :-) In this case, the versatile 2101 pulse generator from 1970.

I had no idea of its condition, so first off, I wiggled all the socketed transistors, then turned it on, saw *some* sort of output, and checked all the supplies (all perfectly fine after 50 years :-) The two shaft couplings are partly broken…I’ll probably just glue them or something :-(

While playing and familiarizing myself with the gear, it suddenly died. Ugh. I thought this would be easy. The core oscillator circuit was still running though, and I finally tracked the culprit to Q182, part of the pulse forming circuitry. The transistor measures largely open now. Weird…suddenly going from working to very dead like that. I stole the corresponding transistor from the delayed pulse generator. Hopefully there is a suitable sub in my junk box.

Next, a more subtle problem. The negative pulse output had a few volts of negative baseline offset. It took me a while to grok the complex output amp circuitry (it’s still somewhat mysterious to me), but after a couple of false trails, I returned to an early hunch: the final, paralleled, output transistors. Sure enough, one of them (Q352) is bad, showing under 1 kΩ from B to C.

Yay…a mostly working unit.

Finding a TO-39 part for the output transistor might be tricky. I do have quite a few in the junk box, but whether any will have good enough AC specs…??? It does kinda hafta be that package, as the heatsink is made to fit it.

As for Q182, it’s an RF transistor—I may have a suitable sub lying around…

So…transistors. Available selection these days seems pretty sad. Am I right, or not? Especially in leaded (no surprise there). The four types of SS xstrs in the 2101 fall into an NPN/PNP-RF/Switching matrix. I sure hope a PNP switch never fails, cuz I couldn’t find a single example at Digikey, regardless of package…

I should know this, but do we have a Tek parts cross reference somewhere in the files? Quite a few parts in the 2101 have no description beyond “Tek Spec”…












Please wrap this up.: RE: [TekScopes] OT: microscope source?

 

40 messages on an off-topic subject is excessive.
I think by now Brad Thompson has enough information to make a decision about Amacope and many other microscopes that may be an aid to his failing vision.
If Brad has any additional questions this would be a good time to ask them.
If anyone wishes to continue the conversation please take it off-line.
Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Tom Gardner
Sent: Thursday, April 15, 2021 3:49 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] OT: microscope source?

On 15/04/21 22:06, Roy Thistle wrote:
On Thu, Apr 15, 2021 at 01:36 AM, Tom Gardner wrote:

I suggest it might be worth some quick and cheap experiments to help
you decide on your equipment.
All these headband thingys seem cheaper on Ebay (but maybe not if you
have Amazon prime.) I find a dizzying plethora of them.. on Amazon, Ebay... and tellingly... less on Bangood!
And just and only in my personal opinion... they are all sub-useful. I say that because... again in my opinion... when Chinese manufacturers find a design that "works" they stick with it... and everyone just copies it. Obviously, they haven't found one they like, at the price point they like. The whole mess of these things is likely junk.
As I noted, they are widely available.

As for being "junk", the type I referred to

* work extremely well for my eyesight and my work
* has been replaced once after 6 years - but at that price it is perfectly
possible to regard it as a consumable

so I don't recognise your meaning of junk.

But as I also noted, YMMV.








--
Dennis Tillman W7pF
TekScopes Moderator


Re: Sony/Tek 380

 

Check the blanking.

On 4/15/2021 9:25 PM, Doug wrote:
I picked up a little Sony/Tektronix 380 Video Waveform/Vectorscope recently. It powered up but no trace,
just a faint glow on the screen. It looked to me that the X10 HV multiplier was bad so I dug out the epoxy
and made a new one. Now the glow is bright but still no trace and the brightness is not affected at all by
the intensity control or the grid bias trimmer, which leads me to believe the CRT is bad.

I have voltage on the focus grid and I tried disconnecting the H and V plates - no change

I removed the CRT to look at the insides. Nothing looks broken or out of place as far as I can tell.
The grid bias trimmer varies the heater to grid voltage from 70V to 130V with, as I said, no intensity change.
Heater is at -1950V.

Looks to me like the CRT is bad. Am I missing anything? Any suggestions?

I've posted some photos under "380".



--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Sony/Tek 380

Doug
 

I picked up a little Sony/Tektronix 380 Video Waveform/Vectorscope recently. It powered up but no trace,
just a faint glow on the screen. It looked to me that the X10 HV multiplier was bad so I dug out the epoxy
and made a new one. Now the glow is bright but still no trace and the brightness is not affected at all by
the intensity control or the grid bias trimmer, which leads me to believe the CRT is bad.

I have voltage on the focus grid and I tried disconnecting the H and V plates - no change

I removed the CRT to look at the insides. Nothing looks broken or out of place as far as I can tell.
The grid bias trimmer varies the heater to grid voltage from 70V to 130V with, as I said, no intensity change.
Heater is at -1950V.

Looks to me like the CRT is bad. Am I missing anything? Any suggestions?

I've posted some photos under "380".


Re: Snubber vs safety cap in 7854.

Martin Hodge
 

On Thu, Apr 15, 2021 at 06:04 PM, Roy Thistle wrote:


Hi Martin:
Well there is already a line filter before the switch ... but, I don't know if
the line filter has line to line X... and line to chassis Y... you could
check.
The only reason for R5, C5, C6 ... that I can see is to protect the bridge
rectifier.
Are you saying that Tektronix moded those out in an updated version of the
schematic?

--
Roy Thistle
Well hey, it's right there in the manual:

"LINE INPUT
Power is applied through line filter FL10, line fuse F10,
and POWER switch S10. The line filter is designed to
keep powerline interference from entering the
instrument and to keep the approximate 25-kilohertz
Inverter signal from entering the power line. Components
R5, C5 and C6 suppress reverse-recovery transients of
CR15"

I'll turn 50 this year. You'd think by now I'd have learned to read the manual.
So, yeah, Tek replaced those three components with one monolithic package made by Rifa.


Re: OT: microscope source?

Tom Gardner
 

On 15/04/21 22:06, Roy Thistle wrote:
On Thu, Apr 15, 2021 at 01:36 AM, Tom Gardner wrote:

I suggest it might be worth some quick and cheap experiments to help you
decide on your equipment.
All these headband thingys seem cheaper on Ebay (but maybe not if you have Amazon prime.)
I find a dizzying plethora of them.. on Amazon, Ebay... and tellingly... less on Bangood!
And just and only in my personal opinion... they are all sub-useful. I say that because... again in my opinion... when Chinese manufacturers find a design that "works" they stick with it... and everyone just copies it. Obviously, they haven't found one they like, at the price point they like. The whole mess of these things is likely junk.
As I noted, they are widely available.

As for being "junk", the type I referred to

* work extremely well for my eyesight and my work
* has been replaced once after 6 years - but at that price it is perfectly
possible to regard it as a consumable

so I don't recognise your meaning of junk.

But as I also noted, YMMV.

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