Date   
Re: ( the price of) printed original manuals

Chuck Harris
 

Hi Dennis,

That is only partly true. The real reason is the Universal
Postal Union UPU), which was established by the Treaty of Bern
in 1874, and all of the subsequent changes to the UPU that
happened in 1969, 2016, ... and 2018.

See <https://en.wikipedia.org/wiki/Universal_Postal_Union>

for a more complete treatment than should be discussed on tekscopes.

Everything is now changed, however, as the US has quit the UPU,
and is refactoring its light parcel postage agreements with the
rest of the world, and especially China.

And for a more complete treatment of the US's quitting UPU than
should be discussed on tekscopes:

See
<https://www.postalandparceltechnologyinternational.com/opinion/is-trumps-decision-to-quit-the-upu-a-bad-thing.html>

The free China shipping will soon be a thing of the past.

Please let's not continue this thread to any great degree. It is
only very loosely related to Tekscopes, in that we often engage in
international shipping to ship scopes and parts.


-Chuck Harris

Dennis Tillman W7PF wrote:

Hi Kevin,
The Chinese government is subsidizing international postal shipments on
purpose which is why shipping to the USA is free from China in almost all
cases. Their purpose is to get us addicted to their products and I can
personally attest to the fact that it works.

Dennis Tillman W7PF

-----Original Message-----
From: Kevin Oconnor
Sent: Saturday, November 10, 2018 8:15 PM
Subject: Re: [TekScopes] ( the price of) printed original manuals

USPS shipping.... U picked an open wound with me. US small mail customers
are getting screwed by international trade agreements. Cheapest <13oz 1st
class parcel for me is ~$5-7 to lower 48.
I get a epacket from China for <$2. Amazon delivers, via USPS, a $5 item
in
an 6x6x10 in box for free. And the USPS is still going broke.

Sent from kjo iPhone


Re: Just got a Tektronix 561A, HV woes...

Albert Otten
 

On Sun, Nov 11, 2018 at 04:19 AM, Jack wrote:


My thoughts, though you are in safe hands it seems, were presuming you are
not somehow measuring personal resistance,...of which you would be acutely
aware...'is there a possibility the heater is contacting another CRT
element?'....In everyday tubes, just as an example, heater-cathode contact can
occur.

Is it worth looking around for a replacement/spare CRT anyway...sooner or
later you might need it and it may help in testing. Perhaps ask the vendor to
measure filament resistance before going ahead. My Regards

--
Jack
In this case a short between heater and cathode would do no harm in that there would be zero voltage across the neons. I would be curious to check for a short between the grid (pin 3) and one of the unblanking plates (pins 6 and 7). Sometimes a short can be blown away with the charged capacitor trick.
Since the CRT neck was found to be warm in one occasion I would also try an external 6 V supply between pins 1 and 14. It's possible that a discontinuity breaks down when 6 V is applied (in stead of the probably much smaller DMM voltage for resistance measurements).

Albert

Re: Beam modulation on 2465B

Chuck Harris
 

Ok, that was what I was hoping you could show.

You have undoubtedly heard of a Lissajous figure,
where the X and Y axis of a scope are driven by two
different sinewave sources... instant techy movie.

Well, what you have here is a Lissajous figure where
one axis is the time base, and the other is the
intensity grid of the CRT.

I would bet that what you are seeing is the EHT
oscillator's AC bleeding through into the CRT's
cathode/control grid circuit.

The first place I would go is to the A9 HV section,
and verify that C1972 is a nice low ESR 100uf capacitor.
The -15V supply goes into a lot of areas, including the
Z-axis hybrid. If that capacitor is bad, you will get
a lot of 50ish KHz ripple on the -15V line.

You can test C1972 in place by using your Rigol scope,
and measuring between P191 pin 8 and chassis ground, and
looking at the 50KHz ripple. There will be some, but
it should be millivolts, not volts.

Next place I would look is in the DC restorer area. Here
I would check the test points 70, 71, 72, 73, and 74,
looking for 50KHz anomalies...

If nothing shows up in the above, you have to move to the
low voltage signal side of the intensity controls, and
the Z-axis hybrid.

Pay attention to the high frequency ripple on the +10V REF
supply... particularly frequencies around 1MHZ (J191-P11).

The ripple source could also be the main inverter of the
power supply.

-Chuck Harris



BUR wrote:

I got so many very interesting and helpful adevices, so the investigation goes further and further.
I have the possibility to shift the frequency by 1Hz. Doing so i discovered more details about the phenomenon.
Shifting 1 by 1 up the modulation goes from the right side to the left and slows down until it stops at 5Hz up then it starts again but no from left to right. Speeding up until about 18Hz up and then the modulation is gone.
I made a short video to replicate this behaviour here: https://www.dropbox.com/s/6itcjie8b64a15h/Direction.mp4?dl=0

Re: 2712 N connector source.

 

Randy,
Jack is referring to one of our newer members, Dinos of Qservice. His contact information is
Dinos
Qservice Electronics
https://www.qservice.tv/

I have bought Tek things from Dinos for many years and I can personally recommend him.

You might also try Walter and Susan Shawlee at Sphere Electronics. They are also someone I highly recommend.
http://www.sphere.bc.ca/

Dennis Tillman W7PF

-----Original Message-----
From: Jack
Sent: Sunday, November 11, 2018 12:34 AM
Subject: Re: [TekScopes] 2712 N connector source.
Hi, a chap who carries a lot of gear is at "qservice-electronics" in
Greece...advertises parts in eBay under the various CRO types and is a
decent bloke.
Tell him Jack from Australia referred you if you like....he's been a great
help to me. This is a random eBay number which would help you find his
store 232997425041. He's a straight shooter unlike some recent others with
Tektronix so I feel ok to receommend him.
--
Jack



--
Dennis Tillman W7PF
TekScopes Moderator

Re: ( the price of) printed original manuals

 

Hi Kevin,
The Chinese government is subsidizing international postal shipments on
purpose which is why shipping to the USA is free from China in almost all
cases. Their purpose is to get us addicted to their products and I can
personally attest to the fact that it works.

Dennis Tillman W7PF

-----Original Message-----
From: Kevin Oconnor
Sent: Saturday, November 10, 2018 8:15 PM
Subject: Re: [TekScopes] ( the price of) printed original manuals

USPS shipping.... U picked an open wound with me. US small mail customers
are getting screwed by international trade agreements. Cheapest <13oz 1st
class parcel for me is ~$5-7 to lower 48.
I get a epacket from China for <$2. Amazon delivers, via USPS, a $5 item
in
an 6x6x10 in box for free. And the USPS is still going broke.

Sent from kjo iPhone



--
Dennis Tillman W7PF
TekScopes Moderator

Re: Soldering tunnel diodes

 

Hi Harvey,
Assuming you iron's tip is small enough to use on a TD just connect your
soldering iron to a lamp dimmer to cool the tip. Simple!
Dennis Tillman W7PF

-----Original Message-----
From: Harvey White
Sent: Saturday, November 10, 2018 1:05 AM
Subject: Re: [TekScopes] Soldering tunnel diodes

On Fri, 09 Nov 2018 11:49:02 -0800, you wrote:

Hey all,

While I was probing the tunnel diode in my 556, one lead of the tunnel
diode popped off the board. It's the kind in the gold-colored metal case,
rather than the little epoxy blob. It tested spot on with a curve tracer
after popping off the board, so it's still okay. I want to know the best
way
to resolder it to the board without damage. Any suggestions? There's not
really enough room for a heat sink clamp since it uses very short leads. I
suspect a little silver epoxy would be okay, but this makes it really
nasty
to remove if that should ever be required. My soldering iron is a metcal
so
it only does one temperature, so I'd prefer not to have to get an iron
just
for doing low melt solder. Will long needle nose pliars be okay as a heat
sink along with standard solder?

Metcal has tips in at least 3 temperatures. There's another company which
makes metcal compatible tips at lower prices. Check amazon.

and I suspect that the pliers would be ok, but I'll defer to people who
use
tunnel diodes.

Oh, and you may wish to get eutectic solder for just such a thing (as well
as SMT parts if you ever use them. Resistors, capacitors, LEDs and diodes
do quite well.

Harvey


--
Dennis Tillman W7PF
TekScopes Moderator

Re: Just got a Tektronix 561A, HV woes...

Xnke
 

I believe I have a spare 561A CRT, and a model 200 scope cart for a 561A.
The cart has 1 drawer and slots for two plugins. I may be contacted off
list about either. Both will be *very* inexpensive...they need a new home.

Located in Kentucky, 60 miles due north of Nashville TN.

On Nov 11, 2018 8:43 AM, "Carlo" <cardis@...> wrote:


Hi

Thanks for the information Jack I will contact him as soon as possible.
Sincerely

Carlo

Il giorno 11 nov 2018, alle ore 09:45, Jack <goldmort@...>
ha scritto:

For parts or another CRT, if struggling, try 'qservice-electronics'.
Located in Greece, you'll find him on eBay selling Tektronix parts. He's
been a
help to me more than I was able to get so far from the site because he
knows well the 425/465M ... and he tells the truth. His postal charges are
fair too. If you like, tell him Jack from Australia referred-you.to
him.

I gave an example elsewhere of an eBay item to make it easier to find
him as it can take a while otherwise, here's another the first of his I
found today..

This eBay item 232965339581 is a rotary switch camshaft for a 475 but
that's by the by,,,it's just a number to take you to his site where he has
a 'store'
and he's ok to be asked for parts. Maybe that helps...or will help....I
don't know..................
My Regards
Jack





Re: Just got a Tektronix 561A, HV woes...

Jack
 

Appreciate your thanks Carlo....the Greek chap Dinos at "Q", lived in Australia for some years so speaks ok English...My regards

Jack

Re: Just got a Tektronix 561A, HV woes...

Carlo
 

Hi

Thanks for the information Jack I will contact him as soon as possible.
Sincerely

Carlo

Il giorno 11 nov 2018, alle ore 09:45, Jack <goldmort@...> ha scritto:

For parts or another CRT, if struggling, try 'qservice-electronics'. Located in Greece, you'll find him on eBay selling Tektronix parts. He's been a
help to me more than I was able to get so far from the site because he knows well the 425/465M ... and he tells the truth. His postal charges are
fair too. If you like, tell him Jack from Australia referred-you.to him.

I gave an example elsewhere of an eBay item to make it easier to find him as it can take a while otherwise, here's another the first of his I found today..

This eBay item 232965339581 is a rotary switch camshaft for a 475 but that's by the by,,,it's just a number to take you to his site where he has a 'store'
and he's ok to be asked for parts. Maybe that helps...or will help....I don't know..................
My Regards
Jack


Re: 468 still trouble shooting Horizontal jitter

tom jobe <tomjobe@...>
 

I think this is the original description of the 468 problem Lop Pol is having:

I'm working on my second 468 and I noticed some horizontal jitter. There is no jitter from the rear vert signal output. What does that mean? What I'm wondering is what is being bypassed when looking at a wave form on another scope through the rear output? Should I be looking somewhere in the CRT circuit of the 468 for the cause of the jitter? The jitter is ALMOST unnoticeable until 10x mag is turned on then its very pronounced.

The fact that has reported the jitter being almost everywhere in the circuits except for the rear vertical output, might help steer someone toward this problem's solution.
tom jobe...

On 11/10/2018 7:09 PM, Jack wrote:
That sounds a smart approach Tom so where possible to troublesome area from other inputs and their power (to exclude 'aerial' induction even including fluorescent lights) and increasingly isolate the fault. I wonder whether the apparently fault producing signal could be fed into another CRO CRT to allow the existing CRT to be pulled-out of the suspect line-up. Reducing the number of "what if's " must make the job simpler. My Regards

Re: Beam modulation on 2465B

BUR
 

I got so many very interesting and helpful adevices, so the investigation goes further and further.
I have the possibility to shift the frequency by 1Hz. Doing so i discovered more details about the phenomenon.
Shifting 1 by 1 up the modulation goes from the right side to the left and slows down until it stops at 5Hz up then it starts again but no from left to right. Speeding up until about 18Hz up and then the modulation is gone.
I made a short video to replicate this behaviour here: https://www.dropbox.com/s/6itcjie8b64a15h/Direction.mp4?dl=0

Re: Just got a Tektronix 561A, HV woes...

Jack
 

For parts or another CRT, if struggling, try 'qservice-electronics'. Located in Greece, you'll find him on eBay selling Tektronix parts. He's been a
help to me more than I was able to get so far from the site because he knows well the 425/465M ... and he tells the truth. His postal charges are
fair too. If you like, tell him Jack from Australia referred-you.to him.

I gave an example elsewhere of an eBay item to make it easier to find him as it can take a while otherwise, here's another the first of his I found today..

This eBay item 232965339581 is a rotary switch camshaft for a 475 but that's by the by,,,it's just a number to take you to his site where he has a 'store'
and he's ok to be asked for parts. Maybe that helps...or will help....I don't know..................
My Regards
Jack

Re: Just got a Tektronix 561A, HV woes...

Harvey White
 

On Sat, 10 Nov 2018 19:01:24 -0800, you wrote:

Hello!

To Mike: I have measured the resistance of the CRT heater filaments again and the reading was 5.22M ohms. You are right, that it's strange that there's a reading, usually would be infinite. I measured this right at the CRT pins. The socket was disconnected. I did check to see if the pins were soldered well and they were.

To Harvey: I am pretty sure that at this point, the scope will be needing a replacement CRT. I hate the idea of turning it into a parts donor. It's probably the only scope that is so clean internally and I have taken a liking to the 561A scopes.
If it's that good then I'd look for a 561 with a good CRT and get that
as a parts donor.

Depends on what you want to do, though. Good clean scopes are hard to
come by.

Harvey



I am having some issues that may be able to aid me. I have tried without success in removing the CRT. This scope must have cushions inside the shield and it's not letting the CRT go. I have no idea what it would take to break the CRT and that's the last thing I want to happen. I think I may have to remove the entire rear CRT clamp and wanted to avoid that. Is there a trick to getting it out?

Thanks for all the help.

Brenda



Re: 2712 N connector source.

Jack
 

Hi, a chap who carries a lot of gear is at "qservice-electronics" in Greece...advertises parts in eBay under the various CRO types and is a decent bloke.
Tell him Jack from Australia referred you if you like....he's been a great help to me. This is a random eBay number which would help you find his store 232997425041. He's a straight shooter unlike some recent others with Tektronix so I feel ok to receommend him.
--
Jack

Re: A new 547 fan

Jack
 

Ok thanks Rajesh....just was interested in your approach. Thanks for the detailed reply, much appreciated.
My Regards,
Jack

2712 N connector source.

Randy.AB9GO
 

Well I am down to the end of the restore job. The last thing to repair is the N connector. Someone stuck something into the N connector and broke the center pin.
Anyone know the manufacturer of the connector? The service manual lists the source as Unitrek, but they made and sold the assembly. They purchased the female N from someone. Any ideas who that could be??

1 CA ASSY, SP, ELEC: SEMI–RIGID TK2469 174–0199–01
TK2469 = UNITREK CORPORATION 3000 LEWIS & CLARK WAY SUITE #2
VANCOUVER WA 98601

Thanks,
Randy AB9GO

Re: A new 547 fan

Rajesh VS
 

Thanks Craig,George and Jack for the comments. Sorry for the late reply,

@ Jack, Answers to your specific questions

why did you not clean the switches when doing the chassis?
==> The interior of the chassis is cleaned mostly with isopropyl alcohol,
and during the cleaning the alcohol sprayed on other parts can wash the
dust down in to switch contacts and can contaminate the contacts. Also most
of the lubrication around the contacts will be lost by this process, That
is why I clean the switches with proper electrical contact cleaner at a
later stage and lube the switch shafts/bearings as well.

and how did the crook rectifier tube evade identification in the tube
testing?
=> Total laziness. I did not test them during the tube testing is the
honest answer, as you know these are soldered in to the ceramic strip and I
assumed(ignored) they will be fine, as I was lazy to desolder them and
test it initially. Same is the story with c335 during my 549 project.

There'll be a reason, just wondering. How did it come to accumulate the
moulds and mud?....any idea.
=> Bit of a story behind this, this scope was kept in a vacant house for
years, and parts of the roof of that home was leaking. The room from where
we recovered this 547 was not much different from a forest floor.

I have my 564 to do at some stage and it's pleasing to receive the
confidence and strategy from someone wiser and more experienced.

==> It is easy and fun to work on these equipment as the circuit design
excellence will keep challenging you, if you dig deep, which is fun I
believe. I follow a slow and cautious approach, which is time consuming but
I like to restore the instrument as close to original condition, without
burning anything out. Some do a direct power up with variac, that also
work. Its just a matter of personal taste. Only suggestion from my side
will be to be systematic, Follow a sequence for restoring/testing - like
Power supply, HV, Trigger/Sweep, H, V Amps so on. Tek reference documents
@ TekWiki will provide you detailed explanation for most of the circuit
designs, specially around trigger/sweep which is tricky to understand.

In case if it helps - I've documented my 549 and RM35 and experience in a
bit more detail with steps in my blog.

549 -
https://lazyelectrons.wordpress.com/2018/01/11/tektronix-549-restoration/

RM35 - https://lazyelectrons.wordpress.com/2018/03/14/tektronix-rm35-rescue/

One of the change I am trying off late is to reform the capacitors, than
replacing or recapping. Only reason I do this is to keep the aesthetics of
the instrument as close to original factory condition.
Details of it on my 575 project -
https://lazyelectrons.wordpress.com/2018/10/13/tektronix-575-curve-tracer-restore/

All the best with 546,

I have a 545, 535 and a RM547 in queue to restore, but really running short
of cycles to work on them.

Thanks & regards,
Rajesh

On Fri, Nov 9, 2018 at 10:45 PM Jack <goldmort@...> wrote:

This is the most useful and well presented...that is simple and very
effective and with inferred safety messages which I have seen on utube .
I'm proud of you and your persistence, resilience strategy and results. Two
questions arose...why did you not clean the switches when doing the
chassis? and how did the crook rectifier tube evade identification in the
tube testing? There'll be a reason, just wondering. How did it come to
accumulate the moulds and mud?....any idea. I have my 564 to do at some
stage and it's pleasing to receive the confidence and strategy from someone
wiser and more experienced. Bravo. Bien Faite, Well Done. My Regards, Jack

--
Jack



--
/Rajesh

Re: Just got a Tektronix 561A, HV woes...

Brad Thompson
 

On 11/10/2018 10:01 PM, brendda75 via Groups.Io wrote:
Hello!
To Mike: I have measured the resistance of the CRT heater filaments again and the reading was 5.22M ohms.
Hello--
Please forgive me for asking an obvious (or previously asked) question,
but is the multimeter (or whatever resistance meter) you used
to measure the CRT's filament continuity working correctly?

If you have access to some resistors in decade steps of 10, 100, 1 Kilohm,
10 Kilohms, 100 Kilohms, and 1 megohm, try measuring one of each value
and recording the meter's readings for each resistor. The purpose of this
test is to verify that the meter's ohms measuring circuitry is working
with reasonable accuracy.

(In my misspent youth, I wasted an evening chasing down some odd
resistance readings, only to discover that the battery powering the
old VOM's ohmmeter circuit was mostly dead.)

73--

Brad AA1IP

Re: Just got a Tektronix 561A, HV woes...

Jack
 

My thoughts, though you are in safe hands it seems, were presuming you are not somehow measuring personal resistance,...of which you would be acutely aware...'is there a possibility the heater is contacting another CRT element?'....In everyday tubes, just as an example, heater-cathode contact can occur.

Is it worth looking around for a replacement/spare CRT anyway...sooner or later you might need it and it may help in testing. Perhaps ask the vendor to measure filament resistance before going ahead. My Regards

--
Jack

Re: More 2712 Spectrum Analyzer fun. Backup battery replacement?

Randy.AB9GO
 

I replaced the batteries today. I used the 3.6V 1/2 AA lithium cells and I had room to spare.
All is working fine. Now I have to perform some service normalizations!