Date   

Re: Type 284 Pulse Generator performance check and quick fix

toby@...
 

On 2021-02-23 9:43 p.m., Rick wrote:
Hi All,

It bought a Type 284 Pulse Gen off Ebay a few weeks ago. I had planned to get it up and running so I could tune up my 5S14N sampler, which will help me fix a TG506's 1ns issue; when all of a sudden my 5440 dies. I decided to look for 5440 that has a readout. Again on Ebay I found a 5440 with readout. Turns out to be pristine, like new 5440 with what looks like new out of the box 5A42 & 5B48's, all for dirt cheap. At only 61, I'm not old enough to have ever seen, let alone own, any new Tek equip. What a treat. Turns out in the new scope my sampler passed it's performance check with minor adj. So on to the 284.

All looked pretty good except for the pulse trigger level. Timing was good but terribly low level at 15mV. It should be around 150mV. This unit has a ton of carbon resistors. I measured the carbon comps around the trigger's two transistors. There were four 5% resistors there and all where sitting at 10%-15% over. The trigger level came back up all the way. Sort of surprised me since most of the time I don't really know what I'm doing. It seems like every Tek repair is so completely different than the previous.
Congratulations! I'm a learning repairer so I like these success
stories, they give me hope.

--Toby


I know the electrolytic caps should be changed. When I lifted the resistors legs the solder had different smell. I pulled the solder fan in, but thought, could this be from the cadmium solder era. It looks like a lot of gold plating inside this thing. Definitely a through back.

Rick






Type 284 Pulse Generator performance check and quick fix

Rick
 

Hi All,

It bought a Type 284 Pulse Gen off Ebay a few weeks ago. I had planned to get it up and running so I could tune up my 5S14N sampler, which will help me fix a TG506's 1ns issue; when all of a sudden my 5440 dies. I decided to look for 5440 that has a readout. Again on Ebay I found a 5440 with readout. Turns out to be pristine, like new 5440 with what looks like new out of the box 5A42 & 5B48's, all for dirt cheap. At only 61, I'm not old enough to have ever seen, let alone own, any new Tek equip. What a treat. Turns out in the new scope my sampler passed it's performance check with minor adj. So on to the 284.

All looked pretty good except for the pulse trigger level. Timing was good but terribly low level at 15mV. It should be around 150mV. This unit has a ton of carbon resistors. I measured the carbon comps around the trigger's two transistors. There were four 5% resistors there and all where sitting at 10%-15% over. The trigger level came back up all the way. Sort of surprised me since most of the time I don't really know what I'm doing. It seems like every Tek repair is so completely different than the previous.

I know the electrolytic caps should be changed. When I lifted the resistors legs the solder had different smell. I pulled the solder fan in, but thought, could this be from the cadmium solder era. It looks like a lot of gold plating inside this thing. Definitely a through back.

Rick


Re: Hi! I am new, but have several Tek scopes

-
 

You do know that the EEVblog posts are 4+ years old don't you?

On Tue, Feb 23, 2021 at 9:18 PM Jeff Dutky <jeff.dutky@gmail.com> wrote:

There's also a fellow with a large collection of spare parts and a list on
EEVBlog forum:
https://www.eevblog.com/forum/buysellwanted/fs-new-test-equipment-repair-parts-hp-agilent-tektronix-fluke-etc/?fbclid=IwAR3MtFDHx2Y9AQ4ame6v6t3VRUqrFZH6uWvfQLn3NR3paAEGgEKsiu0qD58






Re: Hi! I am new, but have several Tek scopes

 


Tektronix 606A that resists being repaired

jrseattle
 

Hi, everyone.

I've been working on a Tektronix 606A XY Display but the unit resists all my repair attempts. So, I'm reaching out to this group for suggestions and assistance.

I've documented my problems here: http://dutchtronix.com/Tek606A.htm

Summary: 2 problems in the HV section, possibly related
problem 1: HV oscillator stops working after about 2 minutes
problem 2: DC restorer circuit (intensity control) not working at all

Any assistance is appreciated.

JdR


locked Re: Slightly OT: How can I dissolve Potting Compound? FOLLOWUP

Dave Seiter
 

That's fine if you have a truck; some of us don't have the option, and no, we're NOT stupid!  Get off your high horse!
-Dave

On Tuesday, February 23, 2021, 07:22:41 AM PST, - <rrrr6789@gmail.com> wrote:

    Wrong, I think that a poorly secured welding cylinder riding in the
backseat of a car would easily snuff the life out of you if you ran into
something. IMO You would have to be very, very, stupid to carry something
like that inside of your car; for a variety of reasons.  People have also
been known to blow up their cars due to leaking cylinders of acetylene and
the like and people have been made sick and probably even killed due to
suffocation hazards from gas cylinders in many kinds of enclosed spaces.
Regardless, I NEVER carry gas cylinders inside of a car and I would not
carry any liquified gas there either.  My cylinders get carried, *strapped
down*, in the *open* back of a truck or a trailer. No exceptions. The same
with hazardous liquids like gasoline, MEK and acetone, etc.  BLEVE?  No
thanks!  Among other things, I've had teachers and friends that have seen
cylinders dropped and the necks broken off and they have described how far
a 200+ pound heavy steel cylinder can fly and the damage that it will do
when it gets stopped!

  BTW I used to live only a few miles from where that Blue Rhino propane
plant in Florida caught fire and exploded a few years ago and I watched as
it repeatedly exploded a few years ago so I know what even propane can do.
Also in around 1974 I was also living quite near Antelope, California when
a train load of 500 pound bombs destined for VietNam caught fire and the
bombs started exploding!  I had returned from VietNam only days before and
I instantly knew what that sound was!  I do play with explosives and very
large fireworks (I'm a member of the largest Pyrotechnics club in the US)
as well as welding gasses and various chemicals but you can bet your asz
that I THINK about what I'm doing and I don't take unnecessary risks.

On Tue, Feb 23, 2021 at 6:33 AM Chuck Harris <cfharris@erols.com> wrote:

A poorly serviced dewar full of LN2, riding in the back seat
of your car, will quite easily snuff your life out, without
you ever even knowing there is a problem...

Your welding gas cylinders won't do that.

-Chuck Harris

- wrote:
  I have welding equipment including Oxy-Acetylene and Helium, CO2 and
25/75 gas for MIG and TIG and the same companies sell all of that also
sell
liquified gasses so I doubt that I'd have any trouble getting liquid N2.
Liquid O2, possibly, but not liquid N2 which in realtively inert and
doesn't support combustion.





Re: TM500 Tester Board Set Deliveries

Larry McDavid
 

Ok, hyphen. Yes, you are the last in the USA to receive the boards. Possibly a weather delay. Most international shipments have been received as well.LarrySent via the Samsung Galaxy S10

-------- Original message --------From: - <rrrr6789@gmail.com> Date: 2/23/21 3:03 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] TM500 Tester Board Set Deliveries Hey Larry,   My long awaited board set finally arrived yesterday.  Only 11 days afterit was shipped!  I think that I must be the last one in the US to receivethem. But everything looks good. Thanks for your efforts.On Sat, Feb 20, 2021 at 4:41 PM Larry McDavid <lmcdavid@lmceng.com> wrote:> I just checked the UPSP tracking info for all the tester board set> shipments mailed on 2/11/2021 and find the following on 2/20/2021:>> 1. All but one USA shipments are delivered>> 2. One USA shipment to Florida is in Orlando, Florida today, 2/20/21>> 3. Two shipments to Alberta, Canada were in Seattle, Washington on 2/18/21.>> 4. One shipment to Quebec, Canada was delivered 2/16/21>> 5. One shipment to Frankford, Germany was in Frankford on 2/14/21>> 6. Four shipments to UK were delivered 2/17 and 2/18/21>> 7. One shipment to Kenilworth, UK is in transit 2/18/21>> 8. One shipment to Australia was delivered 2/19/21>> 9. Two shipments to Australia are in transit 2/16 and 2/19/21>> 10. Two shipments to France are in transit 2/15/21>> 11. One shipment to Ireland is in Dublin 2/14/21>> 12. One shipment to Spain is in Madrid 2/15/21>> I don't know what the delay in the one shipment to Florida is. Maybe> weather... Gosh, there has been a lot of cold and snow out there!>> The USPS tracking of international shipments has little international> detail but at least some show delivered so USPS gets some feedback. I> don't know if that is true for all countries.>> I suggest all who have not yet received the board sets wait until mid> next week. If you still don't have the package, send me a private email> and I'll provide the tracking number.>> The package is 13 x 10 inches in a flat mailer and won't bend in normal> handling. Some have reported the postal carrier has rung the doorbell> and left the package. So, this package may not fit in a standard mail> slot or mail box.>> Many have reported successful delivery to me and all have said the> boards arrived in good condition.>> A comment: Dennis Tillman, based on his experience shipping the many CRT> books, suggested I ask for an emailed postal receipt with tracking> numbers. That was a great idea! If you ship numerous packages at once,> do use the USPS email receipt capability. The tracking numbers on that> emailed receipt are actually hyperlinks, making tracking easier. I was> unaware of that capability and I expect others are also unaware.>> Weather can wreak havoc on all kinds of deliveries. Local COVID> vaccination sites have been shut down for days due to non-local> weather-induced vaccine deliveries.>> One mailer was delivered in one day; many were delivered in two days. I> believe we've got a great post office!>> --> Best wishes,>> Larry McDavid W6FUB> Anaheim, California  (SE of Los Angeles, near Disneyland)>>> >>>


Re: Continued: 2465B CTT/HPIB/WR TEST 05 fail 42, all CTT fail

Chuck Harris <cfharris@...>
 

Hi Jon,

Well, that is what the board swapping was supposed to
determine. Now your efforts can be focused on just the
CTT board.

-Chuck Harris

Jean-Paul wrote:

Chuck many thanks thought so,

Yes I have gone thru Calibrating CTT proceedure and aware of the specific requirements for the signal.

Have all the stuff needed to do it.

As I have mounted a subsitute A5 bd need to replace to the original and do a full CAL anyway.

However it means that the original OPT board has an issue that caused the other flaky tests as orig OPT bod ALL CTT tests fail.

Real puzzle,

Enjoy,


Jon






locked Re: Slightly OT: How can I dissolve Potting Compound? FOLLOWUP

Chuck Harris <cfharris@...>
 

Ah, I have met your sort a thousand times over.

Thanks for making it clear to me that there is less
to you than I ever could have imagined.

-Chuck Harris

- wrote:

Sorry, you didn't find my trigger or you would know that you did with
absolutely no uncertainty. As for "good for me", well that shows a
considerable amount of immaturity on your part and says far more about you
than it does me. And no, I didn't "miss the point". Your point was as
clear then as it is now and I just wanted to point out that I have
CONSIDERABLE experience in this area. I also have considerable more
experience with related equipment than what I discussed but that was in
regards to my work for the US (and other) governments so I don't talk about
any of that, PERIOD.


Re: TM500 Tester Board Set Deliveries

-
 

Hey Larry,

My long awaited board set finally arrived yesterday. Only 11 days after
it was shipped! I think that I must be the last one in the US to receive
them. But everything looks good. Thanks for your efforts.

On Sat, Feb 20, 2021 at 4:41 PM Larry McDavid <lmcdavid@lmceng.com> wrote:

I just checked the UPSP tracking info for all the tester board set
shipments mailed on 2/11/2021 and find the following on 2/20/2021:

1. All but one USA shipments are delivered

2. One USA shipment to Florida is in Orlando, Florida today, 2/20/21

3. Two shipments to Alberta, Canada were in Seattle, Washington on 2/18/21.

4. One shipment to Quebec, Canada was delivered 2/16/21

5. One shipment to Frankford, Germany was in Frankford on 2/14/21

6. Four shipments to UK were delivered 2/17 and 2/18/21

7. One shipment to Kenilworth, UK is in transit 2/18/21

8. One shipment to Australia was delivered 2/19/21

9. Two shipments to Australia are in transit 2/16 and 2/19/21

10. Two shipments to France are in transit 2/15/21

11. One shipment to Ireland is in Dublin 2/14/21

12. One shipment to Spain is in Madrid 2/15/21

I don't know what the delay in the one shipment to Florida is. Maybe
weather... Gosh, there has been a lot of cold and snow out there!

The USPS tracking of international shipments has little international
detail but at least some show delivered so USPS gets some feedback. I
don't know if that is true for all countries.

I suggest all who have not yet received the board sets wait until mid
next week. If you still don't have the package, send me a private email
and I'll provide the tracking number.

The package is 13 x 10 inches in a flat mailer and won't bend in normal
handling. Some have reported the postal carrier has rung the doorbell
and left the package. So, this package may not fit in a standard mail
slot or mail box.

Many have reported successful delivery to me and all have said the
boards arrived in good condition.

A comment: Dennis Tillman, based on his experience shipping the many CRT
books, suggested I ask for an emailed postal receipt with tracking
numbers. That was a great idea! If you ship numerous packages at once,
do use the USPS email receipt capability. The tracking numbers on that
emailed receipt are actually hyperlinks, making tracking easier. I was
unaware of that capability and I expect others are also unaware.

Weather can wreak havoc on all kinds of deliveries. Local COVID
vaccination sites have been shut down for days due to non-local
weather-induced vaccine deliveries.

One mailer was delivered in one day; many were delivered in two days. I
believe we've got a great post office!

--
Best wishes,

Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)






locked Re: Slightly OT: How can I dissolve Potting Compound? FOLLOWUP

-
 

"I found your trigger... good for me.

In taking offense, you miss the point completely, and reinforce
the reason why many suppliers of compressed and liquefied gasses
won't deal with non-business entities."

Sorry, you didn't find my trigger or you would know that you did with
absolutely no uncertainty. As for "good for me", well that shows a
considerable amount of immaturity on your part and says far more about you
than it does me. And no, I didn't "miss the point". Your point was as
clear then as it is now and I just wanted to point out that I have
CONSIDERABLE experience in this area. I also have considerable more
experience with related equipment than what I discussed but that was in
regards to my work for the US (and other) governments so I don't talk about
any of that, PERIOD.

As for me taking "offense", well maybe. But I usually do take offense to
loudmouths that don't know what they're talking about so I don't see that
as being a negative.

But to get to the bottom line, YES, most air gas suppliers WILL sell
liquefied gases to individuals just the same as they will sell them
compressed gasses. I have bought it and friends of mine have bought it.
OTOH there are some air gas suppliers that won't sell *anything* to
individuals. But that is just about their sales policy and not something
particular to liquified gasses.

If you really care to be informed on the subject, which I doubt, then go
over to the WeldingWeb forum. They maintain a running list of suppliers
that will or won't sell to individuals. <https://www.weldingweb.com/vbb/>
I'm one of the members there and on a few other welding forums.

Cheers,

On Tue, Feb 23, 2021 at 10:45 AM Chuck Harris <cfharris@erols.com> wrote:

I found your trigger... good for me.

In taking offense, you miss the point completely, and reinforce
the reason why many suppliers of compressed and liquefied gasses
won't deal with non-business entities.

-Chuck Harris

- wrote:
Wrong, I think that a poorly secured welding cylinder riding in the
backseat of a car would easily snuff the life out of you if you ran into
something. IMO You would have to be very, very, stupid to carry something
like that inside of your car; for a variety of reasons. People have also
been known to blow up their cars due to leaking cylinders of acetylene
and
the like and people have been made sick and probably even killed due to
suffocation hazards from gas cylinders in many kinds of enclosed spaces.
Regardless, I NEVER carry gas cylinders inside of a car and I would not
carry any liquified gas there either. My cylinders get carried,
*strapped
down*, in the *open* back of a truck or a trailer. No exceptions. The
same
with hazardous liquids like gasoline, MEK and acetone, etc. BLEVE? No
thanks! Among other things, I've had teachers and friends that have seen
cylinders dropped and the necks broken off and they have described how
far
a 200+ pound heavy steel cylinder can fly and the damage that it will do
when it gets stopped!

BTW I used to live only a few miles from where that Blue Rhino propane
plant in Florida caught fire and exploded a few years ago and I watched
as
it repeatedly exploded a few years ago so I know what even propane can
do.
Also in around 1974 I was also living quite near Antelope, California
when
a train load of 500 pound bombs destined for VietNam caught fire and the
bombs started exploding! I had returned from VietNam only days before
and
I instantly knew what that sound was! I do play with explosives and very
large fireworks (I'm a member of the largest Pyrotechnics club in the US)
as well as welding gasses and various chemicals but you can bet your asz
that I THINK about what I'm doing and I don't take unnecessary risks.

On Tue, Feb 23, 2021 at 6:33 AM Chuck Harris <cfharris@erols.com> wrote:

A poorly serviced dewar full of LN2, riding in the back seat
of your car, will quite easily snuff your life out, without
you ever even knowing there is a problem...

Your welding gas cylinders won't do that.

-Chuck Harris

- wrote:
I have welding equipment including Oxy-Acetylene and Helium, CO2 and
25/75 gas for MIG and TIG and the same companies sell all of that also
sell
liquified gasses so I doubt that I'd have any trouble getting liquid
N2.
Liquid O2, possibly, but not liquid N2 which in realtively inert and
doesn't support combustion.













Re: Hi! I am new, but have several Tek scopes

 

Steven,

The first thing to try, with any ailing scope, is to check the power rails. For the scopes that aren't showing traces or otherwise failing to come up it's a good bet that one or more power rails are out of spec (remember to check both the voltage and the ripple) probably due to failed filter caps.

For the damaged pot there are several options: first is just to run the part number through eBay and Google and see what turns up, you may find something close enough. Some people on this group have had success taking apart damaged pots, straightening the bent shafts, cleaning the electrical contacts, and reassembling them.

Two commonly used parts suppliers are Sphere Research Corp. (www.sphere.bc.ca), and Qservice Electronics (www.qservice.tv), but there are others as well.

There is a good document from Tektronix titled "Troubleshooting Your Oscilloscope: Getting Down to Basics" https://www.sphere.bc.ca/test/tek-parts/troubleshooting-scopes.pdf

You should post some pics in the photos section, so we can be appropriately envious.

Welcome, and good luck.

-- Jeff Dutky


Re: Vertical attenuator skirted knobs

 

CORRECTION: I've looked at all the 2200-series scopes on TekWiki, and group D knobs don't seem to match any of them. The closest would be D-2 which could be a knob for a 2213/2215 if the 2mV range had been rubbed off, but I doubt that's the case.

Whatever instrument has a vertical range of 2mV to 100V, however, sounds interesting.

-- Jeff Dutky


Re: Continued: 2465B CTT/HPIB/WR TEST 05 fail 42, all CTT fail

Jean-Paul
 

Chuck many thanks thought so,

Yes I have gone thru Calibrating CTT proceedure and aware of the specific requirements for the signal.

Have all the stuff needed to do it.

As I have mounted a subsitute A5 bd need to replace to the original and do a full CAL anyway.

However it means that the original OPT board has an issue that caused the other flaky tests as orig OPT bod ALL CTT tests fail.

Real puzzle,

Enjoy,


Jon


Hi! I am new, but have several Tek scopes

Steven Bender
 

Steven here,

New to this Group, but not new to Tektronix, or various repairs.

I have and love my working Sony/Tek 335, and Sony/Tek 336 small Oscopes, may they show traces forever! I also have (4) not working Tek 2445 scopes that I need to repair, and a dual trace LeCroy 9450A that shows a trace on only one channel (these are on my really long TO DO LIST). In this time of COVID, I recently got three units that are taking up my time and attention, besides those that are just hanging around.

The latest three acquisitions include an off topic set - a Rohde & Schwarz UPL, (nice for audio) this one powers up with a blank white screen, no dos, no boot, no bios, no beep, so it’s problem is not the usual CCFL Failure. I think it runs either a 486DX or maybe an early Pentium 100/133. It has an internal power supply connector blackened/burned, and several of those smt glass cased diodes across the 9! Vregs from output to input, are looking kinda dark, and suspicious, some might be blown. So likely a PS failure (and hopefully nothing else ended up blown, as this unit is just loaded with boards)... (Any UPL owners/users among us????)

The other two recently acquired sets are: a Sony/Tek 335, and also a 336, both with VG cosmetics, but neither one shows a trace. The 335 I noticed has a broken Ch2 position pot, (R222 AB) Tek part 311-1795-00, a front panel .075/.125 shaft 10k/10k ohm dual control. As far as symptoms, the 335 shows a “low line” led, but that’s about it. The 336 will light up some of its push buttons, but also nada in terms of a trace.

I could use some suggestions, help, and that dual pot, there have to be some 335 parts donors still in existence, knobs are OK, just the outer shaft doesn’t connect to the inside part of the control.

Thanks, and you all stay safe!

Steven


Re: NEW TOPIC: Outstanding Rockland Instruments 7000 Plugin; WAS: Slightly OT- Wavetek 7530B?

Steven Bender
 

Gentlemen,

The Rockland 7530A and 7530B are not seriously off topic, because they fit into a Tek 7633 or the 7603, two very popular and commonly found scope mainframe/power supply units

I have one of each Rockland boxes, and a Tek 7603. The 7530A is a working set, but it stressed the 7603’s power supply, such that the system would hang between 20 to 30 minutes after powering on. Eventually, I found that bad or failed solder joints on the several 2N3055 PS main pass transistors was the problem.

The 7530B unit doesn’t work, but after evaluating the innards, those six, (or was it seven) full length boards, seemed almost the same, so I switched one bunch with the other bunch in the 7530A, and the working set still worked! So it’s not the boards it’s something in the 7530B “box” that has failed. I forget which set of boards is currently in the working set, but I never quite finished with the 7603, as it’s so big and heavy, but Iagree, when working, it’s certainly a fantastic setup when evaluating equipment in the audio range.

Steven


Re: Vertical attenuator skirted knobs

 

Walter,

Group A-1 look like they are for the 465 (old-style, with the black ring insert).

Group B-3 appear to be "new style" knobs (without a black ring insert) for the 475 (NOT the 475A, which has a range of 5mV to 100V).

Group D, based on the style of the shafts, appear to be for some 2200-series scopes, not the 233x scopes that you have indicated. They are NOT for the 2213/2215 or the 2235/2236, but there are lots of other scopes in the 2200-series, and I'm not familiar with most of them.

-- Jeff Dutky


Re: Which probe is better suited for 2465B?

Roy Thistle
 

On Tue, Feb 23, 2021 at 10:56 AM, Giuseppe Marullo wrote:


Trying to get them from Ebay, I asked the seller specific conditions/photos
and I will claim the money back if they are not in good order. Anything
specific to ask to be checked, like the button or something similar?
I
If one searches the messages, for P6137, here on TekScopes... there is some discussion about these P6137 (and the other probes, in that family of probes.)
Those threads have some good discussion, about getting them from Ebay.
P6137 are known to be fragile.
Many of these on Ebay have obvious physical damage ( broken tip etc.)... but, some will also have damaged coax (common enough, and not obvious) That might make the probe intermittent... or cause it to become intermittent, with handling.
Unless you really need the P6137's bandwidth... older, lower bandwidth, more hardy, and less costly Tek probes... that can be compensated for the 2465B input capacitance... might server you better.


Re: 465B strange ripple

Mike Merigliano
 

Okay, you did all of the tests, but it was hard to tell given the reporting. For example, is the 55 VDC supply okay as far as ripple goes? I am not the only one to ask about this.

Also, using "ripple" for the trace on your 465B, and ripple on the testing scope screen when checking supplies, is confusing when the context is not clear.

Even though you have "two triggered traces", that does not mean it has to be a trigger problem, and using the trigger hold-off just helps stabilize the display. I use this a lot on my 475 when there are complex signals that are hard to trigger on.

Traces can be noisy even when a scope is working correctly (but not when the voltage switch is at GND - that's not good as you know). I get 1 mV 100-MHz fuzz on a trace even at much longer time divisions if I zoom in (say 10mV per division), but don't worry about it, as it is probably FM radio interference, because I can reduce it with better/shorter probe grounding. Reducing the bandwith with the button makes it disappear of course. Maybe this all makes sense to you.

It looks like you have 50-Hz noise, signal, ripple, or whatever you want to call it, "riding along" on the sweeped trace, and it is likely generated inside the scope somewhere. There were some suggestions on how to find where this is happening, and your recent posts look like you are back on that track.

There is quite a bit of instruction within tek documents etc. that could answer some of your questions, like how to use the Add and Invert function instead of a differential amp, and the disadvantage of doing so.

On 2/23/2021 12:04 PM, Stephen wrote:
Mike,

I DID all the recommended tests except for the one involving a diff amp, which I don’t have.
Ozan suggested that I use the “INVERT” and “ADD” trick, although it was not as good. I asked where I should probe for that, but got no answer. But that’s fine; everyone has their own stuff to do, and I understand that; that’s perfectly normal and understandable.

Anyway, I did all the other tests. And as far as the magnetic issue, I did mention that the problem occurs all the time. Even when the scope is inside it’s box. Even in broad daylight, when nothing is powered on, no incandescent lights, NOTHING is even up and running besides a FG that is not even plugged into the same wall socket. All the shields are also in place, and all the ground connections have been checked.
There is absolutely no visible ripple. Some are even a bit less than what the manual suggests. Some filter caps have been replaced as well. The rectifiers have been checked and are all good.
I have done everything that I could or knew how. I have also been carefully documenting within my posts and most of my pictures, all the voltages and sweep times. I don’t know how much clearer I can be...

Now, something I did notice earlier today, is that at lower sweep times.. I can somehow considerably slow down the ripple to “almost” nothing, when I turn the “HOLDOFF” pot clockwise... But it’s still there, and it makes the calibration of anything X10 related, very difficult, as I can see the pips from my Type 184 rocking horizontally back and forth... Or When trying to adjust “High Speed Timing”, for Example....

BTW, I’m not an EE either. Far from it even. Also self taught.




Re: Continued: 2465B CTT/HPIB/WR TEST 05 fail 42, all CTT fail

Chuck Harris <cfharris@...>
 

The Test81, Fail 03 is a combination of a Fail 02, and Fail 01,
which means that your reference oscillator is not calibrated.

The Test82, Fail 02 is hopefully spurious. Everything is closely
dependent on the oscillator being right. Let's just say that I have
seen it spuriously appear when the reference is uncalibrated, and
spuriously disappear after calibration.

Calibrating the CTT is easy, if you have a good clean frequency
standard that can make either a 50% duty cycle 1Vp-p square wave,
or a 1Vp-p low distortion sine wave at the correct frequency and
stability.

I use an HP3336B, with my GPS disciplined Rb lab standard as
the reference. The 3336B with the high stability option would
be fine by itself.

The HP is set to 1MHz, and makes a nice low distortion sine wave
referenced to the lab standard or internal reference.

-Chuck Harris

Jean-Paul wrote:

Chuck, with known good CTT board exchanged for the one in the failed scope, all cables properly reattached.

A5 board is know good and had no SMD leaky caps.

Only, partial success, CTT works but the following faults on self test:

Test 01 -06 PASS

CT TEST 81 Fail 03
CT Test 86 Fail 02
All others PASS

So really confusing results.

Your thoughts?

Jon






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