Date   
Re: 2465 - No trigger no trace...

Tony Fleming
 

I have the 2465 DMS and it was broken when I received it.
I had to clean + lubricate the BEAM FIND switch! It took some time to
clean, but now it works great!
This switch does much more than you would think, by its function!
Also, check the real voltage from your power supply!
Good luck!
Tony

On Fri, Jul 19, 2019 at 5:00 AM Chris Don <chd3@...> wrote:

Thanks to all! Penguin, you were right to ask this question! - I always
use AUTO trigger and I must have accidentally flipped a switch without
thinking of it as a possible cause (oops)...
The problem is, on this machine, most of the time the status LEDs don't
light during operation (they do light during power-up sequence but remain
off afterward).
I sort of got used to it, but it obviously plays tricks on me and it is
time I look into this issue.
Have you ever encountered this issue? A faulty register?

Thanks
Chris



Re: Tek 485 volts / div knob

 

On Fri, Jul 19, 2019 at 02:33 PM, Chuck Harris wrote:


put your soldering iron tip into the shaft hole and heat the insert
Neat!

Raymond

Re: Tek 485 volts / div knob

Chuck Harris
 

With delrin gears, I use the same heat trick, but I also
play dentist with the gear to strengthen it a bit. If the
gear is big enough, I drill tiny holes on either side of the
crack in the flat part of the gear, and suture them together
using thin steel wire. Once the gear is stabilized, and presents
good fitting teeth around the crack, I use a dremel tool and a
small carbide burr, and cut a channel in the hub near where the
flat part of the gear joins. I suture that channel with thin
steel wire wraps. As the final step, I put JBWeld epoxy over
the sutures to stabilize them, and strengthen them.

If the gear is too small for the suture holes, I cut the groove
around the hub, and wrap it, and then apply the JBWeld epoxy.

I have even gone so far as to fashion a replacement tooth, and
dovetail it into the gear, and fine tune it with a file... but
that was a very desperate time...

I have never had a second failure.

-Chuck Harris

n4buq wrote:

Same kind of problem is prevalent in the (Delrin?) gears inside older HP equipment - particularly the 8640B. I've resorted to removing the hub, boring the hole a tiny bit larger, and then gluing (epoxying) it all back together. Hadn't thought of melting the plastic with the heat of the hub. Nice idea.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@...>
To: TekScopes@groups.io
Sent: Friday, July 19, 2019 7:33:57 AM
Subject: Re: [TekScopes] Tek 485 volts / div knob

If you happen to have the parts, they glue nicely using
a hobby shop solvent glue.

The reason they crack is the plastic shrinks, but the center
hub doesn't. That can be fixed easily. Put the knob pieces
back together around the hub, fitting them as best as you can.
Then take a small rubber band, and bind the pieces in tension
around the hub. Next, turn the knob up, and put your soldering
iron tip into the shaft hole and heat the insert. The instant
the pieces "fall into place", remove the heat and drop the knob
onto a shaft to help the insert cool quickly.

Now that the pieces are all fitting together without stress,
put a drop of solvent glue around the junction of the plastic and
the aluminum hub. This very thin solvent glue will wick into
the plastic cracks and weld them together.

Give it a few minutes to dry, and remove the rubber band, and
admire your handiwork.

-Chuck Harris

Re: Vintage 7104 with all 4 plugs , lookg for trade or sell

 

Hello Tony

I need something basic, for Hobby , entry level testing, Of basic consumer products like the square wave of the Car audio Amplifiers IC's that drive the mosfets
ESC, electronic speed controllers of electric scooters and things like that. 100 or even 50 mhz would probably be ok. 2 to 4 channels . I dont mind use oscilloscope, as long as it works.

Thx

converting an MR501 monitor into a "Huntron Tracker"

 

I have a heavily modded MR501 with almost all the controls removed. it's the same one shown on W140.com as being part of a receiver system. looking at the MR501 manual, it struck me that it does not use the 25VAC winding internally, so I could use this drive to make it into an XY component curve tracer like a huntron tracker easily, since it is already an XY monitor. The AC winding appears to float, so I think it is safe to do this, but any feedback about TM frame problem issues is appreciated.

you can see this uncommon plug-in here on the tekwiki:
http://w140.com/tekwiki/wiki/MR501

For some reason, I am in TM500 mode this month, so I thought I would try and do something with this unit as I work through all the other ones I have sitting around. this idea has been in my head a long time ever since I bought this unit. I hope it can be workable, as space is wickedly tight inside the MR501. I am happy to share my results if anybody is interested in them. It looks like the same thing could be done with an SC501.

all thoughts appreciated.
all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.

Re: converting an MR501 monitor into a "Huntron Tracker"

Mlynch001
 

Sounds like a very interesting use for this plug in. I would like to hear and see more as the project progresses.

--
Michael Lynch
Dardanelle, AR

Re: Vintage 7104 with all 4 plugs , lookg for trade or sell

Tony Fleming
 

OK, what is your maximum investment?
Rigol is a very good start and even more extensive scope than many of the
same kind+price range.
70MHz is good, I would not go any lower speed, but if you can spend the
money, I would 100MHz, if it was me and yes 4 channels!
Go to youtube and watch some videos, before you buy one.
Tony

On Fri, Jul 19, 2019 at 11:36 AM Armando <@Armando49> wrote:

Hello Tony

I need something basic, for Hobby , entry level testing, Of basic
consumer products like the square wave of the Car audio Amplifiers IC's
that drive the mosfets
ESC, electronic speed controllers of electric scooters and things like
that. 100 or even 50 mhz would probably be ok. 2 to 4 channels . I dont
mind use oscilloscope, as long as it works.

Thx



Re: 2465B, 2467B CAL sequence

Jean-Paul
 

Hello All! After a few years of delay and getting A5 boards SMD reworked and socketed, and fixinf fans and graticule lamps, yesterday I finally go bewck to the "gang of 4" scopes!



The 4 scopes are on the bench after NVRAM and battery replacement, 2 of the 4 retained CAL and 2 loaded with a stock image RAM as they were wiped.

I Did a quick power supply V, H and V cal and image check

2 are 100% (did not loose CAL NVRAM) and the remaining 2465B, 2467B are off about 1-4% H cal and similar in VCAL.

Before starting CAL 01 and then CAL 02: Would you recommend to do the CRT Cal as it affects X and Y axis sensitivity? Are the CRT CAL constants also stored in NVRAM?

Or could I save some time and just do CAL 01, 02?

Alternative is a full CAL on all 4 but that will takes days of time.

Open to all opinions from you veterans out there!


Many thanks!

Jon

Re: 2465B, 2467B CAL sequence

Chuck Harris
 

In my not so humble opinion, the best way is
to start from the beginning of the calibration
section, and work to the end.

That said, the CRT adjustments are self
contained, they are section 8, and they are all
computer driven, manual adjustments. Things
like CRT grid current, rotation, ... you can
read the book too!

They can be done at anytime you wish, but should be
done first, because when they are way out, you
can hardly read the screen to do any other calibration.
And, doing the CRT adjustments before the h and v
automatic sections makes it easier for you, as the
markers will align with the screen graticules.

Also, notice that the manual has two sections for
CRT adjustments: 2467B and 2465B. Write something
on the first page of each of those sections to
call attention to which scope they belong to.

I can't tell you how many times I tried to do the
2467B's CRT adjustments on a 2465B, before I marked
the sections.

And, yes, even after all of the calibrations I have
done, I still go through the book when calibrating.

-Chuck Harris

Jean-Paul wrote:

Hello All! After a few years of delay and getting A5 boards SMD reworked and socketed, and fixinf fans and graticule lamps, yesterday I finally go bewck to the "gang of 4" scopes!



The 4 scopes are on the bench after NVRAM and battery replacement, 2 of the 4 retained CAL and 2 loaded with a stock image RAM as they were wiped.

I Did a quick power supply V, H and V cal and image check

2 are 100% (did not loose CAL NVRAM) and the remaining 2465B, 2467B are off about 1-4% H cal and similar in VCAL.

Before starting CAL 01 and then CAL 02: Would you recommend to do the CRT Cal as it affects X and Y axis sensitivity? Are the CRT CAL constants also stored in NVRAM?

Or could I save some time and just do CAL 01, 02?

Alternative is a full CAL on all 4 but that will takes days of time.

Open to all opinions from you veterans out there!


Many thanks!

Jon

Re: 2465B, 2467B CAL sequence

Jean-Paul
 

Chuck as always your sage advice is spot on!

Another question is the transient response adjustment all analog pot and cap tweaks or are calconstants storned in NVRAM?

À BIENTÔT


Jon

Re: 2465B, 2467B CAL sequence

Chuck Harris
 

It is a little of both. There are two networks
of capacitors, pots, and inductors that manually
get tweaked for best shape, and there is a set of
constants that adjust a bias in the channel switch
that gets stored in the NVRAM.

-Chuck Harris

Jean-Paul wrote:

Chuck as always your sage advice is spot on!

Another question is the transient response adjustment all analog pot and cap tweaks or are calconstants storned in NVRAM?

À BIENTÔT


Jon



Are the 5100 series scopes known for intensity/focus problems?

Dave Seiter
 

I ask because I have three 5110s I've decided to get working so I can whittle them from the collection, and after solving many other issues, all three have some combination of intensity/ focus related issues. I got them all from the same auction years ago, and all of them were missing the metal CRT connector cover. (I guess that should have been a hint!) On all three, removing and reseating the CRT connector solved at least one other problem. They are all the newer versions (square heatsinks on the H and V output xstrs, and row of fuses in the LVPS).

Sometimes, depending on settings, I get classic double peaking behavior, but sometimes it's more like a scratchy pot (same scope). In one case, the focus literally has two shapes- it remains stable until the knob is turned past a certain point, then it changes to it's other stable state. I'm thinking that one might be a bad pot. On some settings the focus and intensity interact a little, but not on others. The plugins all work just fine in the 5111.

Lastly, on one scope, each trace begins with a small spot, regardless of settings (except for x10 at higher speeds, where the spots vanish, but the retrace is visible. Must be a blanking issue, but that's the last problem I noticed and haven't looked into it yet.

-Dave

Re: 2465B, 2467B CAL sequence

Jean-Paul
 

Dear Chuck: Last question (hopefully!)

I need to CAL all 4 scopes, 2465B/2467B. I have required equipment, fixtures, etc (TM501, PG506, precision cable, atten)

a/ Do you recommend do a complete CAL on scope 1, proceed to scope 2 etc

OR


Setup first test eg PSU/DAC cal, run on all 4 scopes, proceed to CRT setup on all 4, then CAL 01 on all 4?

b/ I might have to interrupt the sequence eg do CAL 01, CAL 02 on one day to all 4 and then resume at CAL 03 etc the next day.

Is Each CAL procedure is independent of the others, thus start CAL 01, complete and exit>>stored in NVRAM, proceed to CAL 02

OR must EVERY CAL 01-08 be done in order and finished before ALL are recorded in NVRAM?

Many thanks again!

Jon

Re: 2465B, 2467B CAL sequence

Chuck Harris
 

I think it is better for a non production (manufacturer) to
go through the entire calibration for each scope separately and
fully to completion, before moving on to the next scope.

I could see where a production line might want to have a technician
specialize on only one step (CAL06 Transient Response), but that
would only work if the volume of scopes available for calibration
would support that kind of specialization. (eg. have enough scopes
so that a technician could be kept busy doing just CAL01...)

The NVRAM constants are stored as you go, and the checksums
are computed when you finish a full calibration step... eg. CAL01.

So, if you get tired after finishing CAL03, and want to quit for
the night, by all means do so. If you simply have to take a break
at, say, CAL03, step 13, do so, but leave the step running.

(By quit, I mean press A/B and leave the calibration routine.)

Always complete a major routine (e.g. CAL03) before quitting the
calibration routine.

-Chuck Harris

Jean-Paul wrote:

Dear Chuck: Last question (hopefully!)

I need to CAL all 4 scopes, 2465B/2467B. I have required equipment, fixtures, etc (TM501, PG506, precision cable, atten)

a/ Do you recommend do a complete CAL on scope 1, proceed to scope 2 etc

OR


Setup first test eg PSU/DAC cal, run on all 4 scopes, proceed to CRT setup on all 4, then CAL 01 on all 4?

b/ I might have to interrupt the sequence eg do CAL 01, CAL 02 on one day to all 4 and then resume at CAL 03 etc the next day.

Is Each CAL procedure is independent of the others, thus start CAL 01, complete and exit>>stored in NVRAM, proceed to CAL 02

OR must EVERY CAL 01-08 be done in order and finished before ALL are recorded in NVRAM?

Many thanks again!

Jon

Tektronix SP232 eprom dump

Giampi Redmond
 

I have a SP232, serial extended function module, for Tektronix TDR 1502B/C - 1503B/C which suddenly failed.
After a search the fault would reside in the eprom U1016 (27C512) which probably got corrupted.
Has anyone by chance done and has the dump of this eprom?
The Tek code should be 160-4978-00, Thanks.

Re: Vintage 7104 with all 4 plugs , lookg for trade or sell

Reginald Beardsley
 

I'm interested in the scope. I sent a PM, but have not heard anything and I did not get a copy in my mailbox.

Please email pulaskite@... if the scope is still available.

Thanks,
Reg

Re: converting an MR501 monitor into a "Huntron Tracker"

Ed Breya
 

Sounds like a good use for it, but if internal space is very limited, it may not be possible to fit the extra parts needed. The biggest issue would be the series power resistor(s) that set the test current range(s). It depends on how much juice you want to be able to supply. If the mainframe pass transistors are uncommitted, you can use them to make a synthetic variable power resistor. This would take some extra circuitry, but at least the power dissipation would be in the mainframe rather than the plug-in, and it could be more compact overall.

Another option may be to build a separate plug-in to go with it, to provide the test sources, with more available options from its windings and transistors, and panel space. Of course, this takes up a full slot, so it's not as compact or "cute" as it would be to squeeze a simple tester function into the original unit.

Ed

MR501 HT Success!

 

Well, 5 resistors and a rotary switch did the trick, I now have a variable range "huntron tracker" up and running in that modded MR501.

it is currently in "ugly" prototype stage, literally held together with some tape, and running on an extender cable but I wanted to be sure before cutting the panel that the idea was workable with no surprises. I still have to tweak some gains to prevent traces falling off the screen, but I have great performance from low voltage to about 10Vfs, and easily within the range of all the controls.

I can send some pics to anybody interested, the process was very simple:

1. attach twisted pair to rear 25VAC wining on 13A/B, run that to a small pcb with the range resistors.
2. remove rear connector X/Y connections on 16/17 for re-use.
3. remove the vertical gain pot from the front.
4. install 3 pos rotary (min. grayhill) in its place, run to pcb to select input voltage from divider pcb..
5. add vertical current sense 1K resistor across the vertical input.
6. connect common and horiz input to the pcb.
7. cable BNC for sample input.

now I have to add a BNC to front, thankfully the shell goes to ground/circuit common, or an insulated BNC would be needed. using a BNC to mini-grabber cable makes testing a snap.

there is a bit of end trace distortion (most visible on circular cap traces) due to other rectifiers sharing the same core transformer as the test winding. very minor issue, but interesting to see how loads affect the primary transformer reflected back to the line.

I looks very usable, certainly more so than the raw MR501 I started with.I will provide better pics and info once it's finished.
all the best,
walter (walter2 -at- sphere.bc.ca
sphere research corp.

T912 missing trace solved- quick LM3086 question

Dave Seiter
 

Man, are my skills getting rusty! Took me way too long to determine that Ch1 on my T912 wasn't working because one of the xstrs in U4134 (LM3086) wasn't passing the signal. (Ch1 -vert sig path) Seems like an unlikely failure, but I guess anything's possible. It's going to be a hassle to replace, but it's my only portable storage scope. Anyone seen this failure before in a T9xx scope?

-Dave

I promised myself I wouldn't....

Dave Seiter
 

You have to draw the line somewhere, and in my case it was: no portables (other than my T912, which was my second scope). But I was at an estate sale on Friday, and there was a very nice 465 with cover, probes, manual, pouch, etc. I just couldn't say no, especially when I added a TM504, TM503, DM502A, AM502, some oddballs: DP100, SA501 and 067-1039-00, a box of misc probes and unrelated goodies, some manuals, a servo actuated 3PH powerstat and got an excellent price for the whole pile. The guy had been an imaging engineer, and had apparently worked on a lot of movies with Coppola, Lucas and others. There were tons of analog video equipment that will go to the recycler. I almost left the pattern generator, but it looked brand new; maybe there's still a use for it somewhere.

The 465 needs a cal, but everything seems to work except for ALT/CHOP, which has issues.

I promise, this is my last portable, really!

-Dave