Date   

Re: Looking for an T5611-25 CRT (or -7 or -2)

Bob Rosenbloom
 

Yes, that's a Calcomp 960 plotter with it's 907 controller. Some better photos of that can be seen about 1/3 the way down here: http://www.dvq.com/oldcomp/misc.htm. I restored that plotter about 10 years ago.

DEC used the 611 monitor on some of their PDP-8 systems. They painted it black and rebadged it DIGITAL. I have a few of those but they are not currently hooked up to anything. Fun stuff.


Re: PS503A max current

 

The 20V supplies are not independent and cannot be paralleled. The negative of the positive supply and the positive of the negative supply are common and cannot be separated.

A module such as this could give up to 3 amps at 3.3V from one of the 20 volts supplies: https://www.ebay.com/itm/223524573272

--
Bob Haas


ADMIN: TekScopes Moderators Required

Michael Dunn
 

Hi everyone. While Dennis has been doing a fantastic job running TekScopes, he could use some help and backup (which of course I’ve provided in the past whenever possible). So, we’re looking for one or three people who can share the duties.

What are the requirements?

1. Ideally you’ve moderated a group before, but more importantly, are “good with computers” and can generally figure out things on your own. The group mostly runs itself—the main task being to approve members’ first posts.

2. You follow or at least scan group postings, so you can keep on top of any issues that may arise.


Please don’t “apply” unless you’re quite sure you want to do this. I.e., we don’t want to be overwhelmed with applications :-} Tell us who you are and about yourself a bit, how long you’ve been in the group, etc.

This isn’t really a topic for group discussion, so please, let’s not start. Also, suffice to say that anyone who responds to this via the group will be barred from consideration! (that’s your first test) You can reply to me, but, no…better to send to the general “Moderators” email so both Dennis & I get it. That’s your second test ;-)

Thanks!
Michael


Re: Looking for an T5611-25 CRT (or -7 or -2)

 

The vintageTEK Museum can probably supply a CRT, but I doubt we have anything but P31 phosphor. I will be at the Museum tomorrow (Wednesday) and will check our stock.

--
Bob Haas


Re: What do you do when you get a call from AUSTRALIA

Nenad Filipovic
 

On Mon, Jul 12, 2021 at 6:37 AM Dennis Tillman W7pF <dennis@ridesoft.com> wrote:
Give me a few days to get caught up
Dennis Tillman W7pF
Thank you for your concern!!!
That really means a lot to me.
I'm happy to be back!!!
Who was it that called me all the way from Australia. I need to thank them
personally.
Hi Dennis, I'm glad you're OK and back with us. I second everything the rest of the group has said, especially the invitation to reach out. I hope the number of replies in this thread is enough of a proof that even if you don't feel like it (socializing), group members won't forget about you and will give comfort and support.

On Tue, Jul 13, 2021 at 04:13 AM, cheater cheater wrote:
I wanted to suggest something else, too. If we're feeling a bit more
generous with our contacts here, maybe we should also consider a voice
and real-time chat option to talk. I suggest setting up a Discord
server. If people here are OK with this idea I will post a link to a
discord server. It doesn't cost anything. Just want to know if people
are fine with it.
I think this may be a very good idea. Compared to other voice/video messengers, Discord is less invasive and gives the ability to limit yourself only to those features you find suitable (e.g. only chat and messages if voice/video calls are too much hassle for you). It might bring modern air to the group and serve multiple purposes - people would be able to assist each other in real time and with the aid of a camera, or just use the plain old text chat. Would be good to hear what think, perhaps it deserves a thread of its own?

Best regards,
Nenad FIlipovic


Re: What do you do when you get a call from AUSTRALIA

 

Hi Dennis,
funny post, and I'm glad you're doing as well as you're doing. It can
be tough, I know from experience. If there's anything we can do let us
know. Chris called you but he was acting in name of all of us here.
Just know you're always welcome here, whether feeling good or feeling
crap. If you're feeling really really bad please don't hesitate to
reach out. Always there to help. I don't think anyone on the list
would object to anyone on the forum to reaching out like this, to talk
to the fine folks on the forum.

I wanted to suggest something else, too. If we're feeling a bit more
generous with our contacts here, maybe we should also consider a voice
and real-time chat option to talk. I suggest setting up a Discord
server. If people here are OK with this idea I will post a link to a
discord server. It doesn't cost anything. Just want to know if people
are fine with it.

Cheers

On Mon, Jul 12, 2021 at 6:37 AM Dennis Tillman W7pF <dennis@ridesoft.com> wrote:

Yesterday was a really nice day.
The temperature was perfect, the sun was out.
I was on the deck of our little summer house working on my computer.
In front of me across an inlet of Puget Sound I can see snow covered Mt
Rainer 40 miles away.

Suddenly my cell phone rings.
Annoyed! I pick it up to look at the screen and it says in all capital
letters:
AUSTRALIA
Underneath that seemingly giant word is a strangely formatted phone number.
That strange format could only belong to an international telephone number.

This is exactly what my brain said to me in the next 2 seconds between the
2nd and the 3rd ring.
"Holy Crap!"
"It's a mistake"
"I don't know anyone in Australia"
"It's a robo-call. It must be"
"Wait a minute, nobody makes robo-calls from Australia"
"The number format means it really might be coming from Australia"
"Why would anyone want to call me from Australia"
"It's a new trick by the robo-callers to get people to answer and listen to
their recordings"
"They must have mis-dialed"
"They accidentally sat on their phone and pressed a bunch of numbers at
random"
"I don't know anyone in Australia" (that was the second time my brain said
this to me to make sure I got the point)

Then my brain shut up for a moment while it waited to see what I would do
next.
I realized someone probably went to a lot of trouble to find me. So I
answered.

ARGH! It was someone from TekScopes who was very concerned that I was OK
because I disappeared about 4 weeks ago without a trace. We had a very long
talk about what was going on. I was in a depression and couldn't get out of
it. I was overwhelmed with all the things going on in my life - most of them
it seemed to me were going badly. I have suffered from depression almost my
entire life. Until I was in my late 40s I had no idea this was the case. By
then I spent several years in therapy with several different therapists and
eventually one Psychiatrist I was seeing worked out the right balance of
medications for me to take for the rest of my life to help me avoid falling
into another depression. Depression is a learned behavior and the real
danger about it is that the more it happens to you the easier it is to
become depressed. Once I am in one it is like a trap and I can't get out.

But the phone call and the conversation I had with the caller - he said his
name so fast I didn't have a chance to get it was wonderful. He understood
completely what I was going through. That call made it possible to spend
most of today catching up on my email and facing the world once again. I'm
still a little shaky (mentally) but I think (I hope) I will be on my feet
again (mentally) in a few days.

In the meantime I would like to thank Michael Dunn for covering for me. He
and I both agree I could use help with TekScopes because it beginning to
take up too much of my time (that was one of the things I was not able to
spend enough time on but I didn't know how to fix it).

Give me a few days to get caught up
Dennis Tillman W7pF
Thank you for your concern!!!
That really means a lot to me.
I'm happy to be back!!!
Who was it that called me all the way from Australia. I need to thank them
personally.








Re: Looking for an T5611-25 CRT (or -7 or -2)

Tim Phillips
 

From Tim P (UK)

Awesome collection ! Is that a Calcomp Drafting Plotter partly cut off on
the far right-hand side of photo ?
I remember seeing one plotting layouts for IC fab, which were then
photo-reduced by many orders of magnitude using ultra-high-resolution
lenses by, I believe, N*k*n, to make the masks. (pre-EBL)
Also, some PDPs used the Tek storage monitors, I think the 604 and 611.

Tim

On Tue, 13 Jul 2021 at 04:27, Bob Rosenbloom <bobalan@sbcglobal.net> wrote:

I also have a PDP-12, though mine uses a DEC VR14 for the monitor. It's a
11 or 12" CRT with magnetic deflection and a P7 phosphor. It also has two
TU-56 DECTAPE units but unfortunately no DF32 or paper tape reader/punch. A
few photos of the PDP-12 are here:

http://www.dvq.com/dec-pdp12/

The VR14's tube was not lighting up so I removed it. Turns out the base
was loose and actually fell off. Nothing was broken, the wire pins out of
the back of the CRT just were not soldered to the base anymore. I
re-soldered them and glued the base back on and now the tube lights up.
There's still work need on the deflection amps though.

Here's a photo of my 12 bit DEC collection showing the LINC-8 next to the
PDP-12. http://www.dvq.com/dec-pdp12/dec-12bitters.JPG

The PDP-12 is built out of M-series flip-chips where were TTL based. The
LINC-8 uses mostly R series transistor, no IC, modules. It a few years
older than the PDP-12. At the far right is a PDP-5 which used system
building block modules. They were made out of germanium transistors. Same
modules as used in the original LINC computer and DEC PDP-1.

There's two Tek 7954 scopes at the left, and an RM-503 above a PDP-8/i.
That has a nice, bright, P2 phosphor CRT.

The LINC-8 is going to be a big project. It's missing around 100 cards for
one, then the badly burned CRT, and it's missing it's LINCTAPE drive.






Re: What do you do when you get a call from AUSTRALIA

 

Dennis,
G-d bless you!

There is no better cure for depression, than hanging out with a few good men, and opening up.
At the end of the day, we're all just a bunch of f... jerks, battling through life.

It's much easier, and much more fun to not do it alone.


Re: Looking for an T5611-25 CRT (or -7 or -2)

Bob Rosenbloom
 

I also have a PDP-12, though mine uses a DEC VR14 for the monitor. It's a 11 or 12" CRT with magnetic deflection and a P7 phosphor. It also has two TU-56 DECTAPE units but unfortunately no DF32 or paper tape reader/punch. A few photos of the PDP-12 are here:

http://www.dvq.com/dec-pdp12/

The VR14's tube was not lighting up so I removed it. Turns out the base was loose and actually fell off. Nothing was broken, the wire pins out of the back of the CRT just were not soldered to the base anymore. I re-soldered them and glued the base back on and now the tube lights up. There's still work need on the deflection amps though.

Here's a photo of my 12 bit DEC collection showing the LINC-8 next to the PDP-12. http://www.dvq.com/dec-pdp12/dec-12bitters.JPG

The PDP-12 is built out of M-series flip-chips where were TTL based. The LINC-8 uses mostly R series transistor, no IC, modules. It a few years older than the PDP-12. At the far right is a PDP-5 which used system building block modules. They were made out of germanium transistors. Same modules as used in the original LINC computer and DEC PDP-1.

There's two Tek 7954 scopes at the left, and an RM-503 above a PDP-8/i. That has a nice, bright, P2 phosphor CRT.

The LINC-8 is going to be a big project. It's missing around 100 cards for one, then the badly burned CRT, and it's missing it's LINCTAPE drive.


Re: What do you do when you get a call from AUSTRALIA

Robert Simpson
 

Dennis,
Our best thoughts and feelings for you. I hope you can feel the good vibes this group has for you.
Best wishes,
Bob


PS503A max current

Robert Simpson
 

I have a working PS503A in my TM504 right slot. I need a power supply with more than 1 amp at a low 3.3 volts. Can the two independent 20V supplies be run in parallel similar to the way they can be run in series for 40V?
Bob


Re: TDS-540B Repair?

Stephen Hanselman
 

Yes they are pricey, but the kit is well built with excellent instructions. Their display is a bit sharper than the CRT especially when the CRT is in decline.

Regards,

Stephen Hanselman
Datagate Systems, LLC

On Jul 12, 2021, at 15:24, Christopher Maness <christopher.maness@gmail.com> wrote:

I borrowed my friends scope in the meantime. It is a small LCD. It is
cool, but feels like a downgrade in quality of the scope. I love the
precision of the 540.

On Mon, Jul 12, 2021 at 3:11 PM Jim Ford <james.ford@cox.net> wrote:

Another issue is space. Sure, I'd love to have multiple parts mules for
every piece of gear I own, but where the hell would I put it all? Property
values are so high here in Southern California that most of us don't have
much of it. OTOH, a new LCD replacement for a CRT would take up zero extra
space. Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Roy Thistle <
roy.thistle@mail.utoronto.ca> Date: 7/12/21 2:48 PM (GMT-08:00) To:
TekScopes@groups.io Subject: Re: [TekScopes] TDS-540B Repair? On Mon, Jul
12, 2021 at 02:33 PM, Stephen Hanselman wrote:>> These are great mods>Yes,
but pricey... they're called "NewScope LCD kit" For the price, I'd rather
get "Another Scope Kit"... and take the parts from that mule.But if money
is no object... go for it.They have kits for HP scopes too.-- Roy Thistle








Re: RSA 3408 A Real time spectrum analyser

nj902
 

Mine runs XP. It's been rock solid.


Re: Members in Australia

Allan
 

Hi All

Another 2247a, 2465 & 2465b owner in Gulgong NSW Just a guy with all the gear.... but no idea.... :-)

cheers...Allan


Re: Cleaning Scratchy Bourns MOD pots

 

I'm trying to clean and lubricate the INTENSITY control on a 7603. The control is a Bourns mod pot with three sections: two potentiometers (0-5k) and a switch. It is an old-style black and brown variety that is held together with screws. Tek part# 311-1404-00.

Getting the sections apart was easy enough (just unscrew four screws), but I can't seem to get into the potentiometers themselves. There's no direct access to the wiper and track from either side. It looks like the brown part of the section should slide out, but I have not been able to budge it by applying moderate force.

Does anyone have any advice on how to get the individual potentiometer sections open to clean and lubricate the wiper and track?

-- Jeff Dutky


Tek 2712 SA Issue

Howard Hoyt
 

Hi all,
I have a 2712 Spectrum Analyzer which last year started giving file system cleanup errors on boot. I replaced both PCB backup batteries and that seemed to clear that problem up until today when it began doing the same thing. The first set of batteries lasted 20 years....anyone have a clue why this should happen again in less than a year? Other than this error on boot the unit appears to be working correctly.

Thanks in advance!
Howard Hoyt


Re: TDS-540B Repair?

Christopher Maness
 

I borrowed my friends scope in the meantime. It is a small LCD. It is
cool, but feels like a downgrade in quality of the scope. I love the
precision of the 540.

On Mon, Jul 12, 2021 at 3:11 PM Jim Ford <james.ford@cox.net> wrote:

Another issue is space. Sure, I'd love to have multiple parts mules for
every piece of gear I own, but where the hell would I put it all? Property
values are so high here in Southern California that most of us don't have
much of it. OTOH, a new LCD replacement for a CRT would take up zero extra
space. Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Roy Thistle <
roy.thistle@mail.utoronto.ca> Date: 7/12/21 2:48 PM (GMT-08:00) To:
TekScopes@groups.io Subject: Re: [TekScopes] TDS-540B Repair? On Mon, Jul
12, 2021 at 02:33 PM, Stephen Hanselman wrote:>> These are great mods>Yes,
but pricey... they're called "NewScope LCD kit" For the price, I'd rather
get "Another Scope Kit"... and take the parts from that mule.But if money
is no object... go for it.They have kits for HP scopes too.-- Roy Thistle





Re: Calibrate the time base, or horizontal amplifier?

emissionlabs
 

Here is how I did the calibration without time mark generator.

Using a 5B10B time base and a 5A14N vertical module in slot #1.

The +30V has a very small tolerance, which I used to calibrate the scope calibrator output. So I set the +30V until I had exactly 400mV on the calibrator, and the 30V was still within calibration. 400mV measured with an Agilent 34401A. Then I set the -30V to exactly the same level. So +30 and -30 are nicely balanced.

Make the calibration signal visible with 4 divisions vertical.

The sensitivity at the backplane is 50mV/cm. I soldered two wires on the PCB of the 5A14N, which lead to pins 7A and 7B. I hooked those up to the Agilent 34401A. Connect the calibrator to the vertical module input, and use the "Cal" potmeter to adjust the backplane signal to exactly 200mV. So 4 divisions on the screen. Do not touch this potmeter setting. Any deviation is now caused by the vertical amp. Adjust the vertical gain for 4 divisions.

The next step is a bit strange, but the manual sais so too.

Swap the time base module and the vertical amp.
This rotates what you see on the CRT by 90°. The vertical amp output which has a known 200mV still, is now in the time base slot (#3). This 200mV drives the horizontal amp. Adjust it for 4 divisions.

So now the vertical and horizontal amp are cablibrated.

Put back the time base and the vertical amp in the normal slots, and make the calibration signal visible. Any error is now caused by the time base being too slow or too fast. The calibration signal is not 50% duty cycle nicely. So I used a digital controlled oscillor and set it for 10kHz square wave. Now adjust the timebase to 10kHz is displayed correct.

That's it. A bit unconventional, and I hope there is no mistake in the system, but it worked very good.


Re: TDS-540B Repair?

Jim Ford
 

Another issue is space.  Sure, I'd love to have multiple parts mules for every piece of gear I own, but where the hell would I put it all?  Property values are so high here in Southern California that most of us don't have much of it.  OTOH, a new LCD replacement for a CRT would take up zero extra space.             Jim Ford  Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Roy Thistle <roy.thistle@mail.utoronto.ca> Date: 7/12/21 2:48 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] TDS-540B Repair? On Mon, Jul 12, 2021 at 02:33 PM, Stephen Hanselman wrote:>> These are great mods>Yes, but pricey... they're called "NewScope LCD kit" For the price, I'd rather get "Another Scope Kit"... and take the parts from that mule.But if money is no object... go for it.They have kits for HP scopes too.-- Roy Thistle


Re: RSA 3408 A Real time spectrum analyser

Roy Thistle
 

On Sun, Jul 11, 2021 at 09:36 PM, nj902 wrote:


You should also capture an image of the hard drive
One really should. (One won't realise how germane that recommendation is until Win 2000 begins working its evil.)
--
Roy Thistle

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