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In case it isn't apparent from the information below, I created a small
PDF that outlines the procedure I used to replace the electrolytics in my
465B using an auxiliary PC board and snap-in caps. I've shared the
pictures in the photo album but this makes it a little more organized.

Note that I'm going to order another batch of boards as I'm pretty much
sold out. Should take about a week before they get here.

Thanks,
Barry - N4BUQ

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

From: "[email protected] Notification" <TekScopes+notification@

groups.io>

To: [email protected]
Sent: Sunday, July 29, 2018 2:44:43 PM
Subject: [TekScopes] New file uploaded to [email protected]

Hello,

This email message is a notification to let you know that a file has been
uploaded to the Files area of the [email protected] group.

*File:* Replacing Electrolytic Filter Capacitors in a Tektronix 465.pdf

*Uploaded By:* n4buq

*Description:*
Step by step procedure for replacing the electrolytic capacitors in a

465B

using an auxiliary board with snap-in capacitors.

You can access this file at the URL:
/g/TekScopes/files/Replacing%20Electrolytic%20Filter%

20Capacitors%20in%20a%20Tektronix%20465.pdf

Cheers,
The Groups.io Team

From: Adrian <Adrian@...>
Sent: Jul 29, 2018 5:50 PM
To: [email protected]
Subject: Re: [TekScopes] Slightly OT - Bourns trimmer pot failure

Hi Michael,
Did that and not a trace of anything, just a ‘bruise’ where a dimple in the stake has been pushed hard against the surface as if to make contact. I am really beginning to think this has been faulty from day one.
Adrian

Adrian
Sent from an I-thingy

On 29 Jul 2018, at 10:39, Michael A. Terrell <mike.terrell@...> wrote:

The failures I saw with the Beckman pots were in telemetry receivers being built for NASA. They were the ones in use when we lost that last shuttle. The media was waiting for information, but when you had built the equipment for the earth stations, with dual diversity at every tracking site I knew as soon as they stated, We have a loss of telemetry' that we had lost another shuttle. It was like a kick in the gut, hoping for the impossible in that six complete systems had failed at the same instant instead of the loss of the shuttle.

We couldn't wait for Beckman to decide that we were right, because our products were used by many Aerospace companies where failures could cost hundreds or thousands of lives. They forced us to make the change, and only by removing a company from the master Approved Vendor List could we make sure that no one substituted anything else. Purchasing was then forced to state 'NO SUBSTITUTIONS ALLOWED ON THIS ORDER'.

As an example, a distributor offered purchasing some tighter tolerance molded inductors for a lower price than the approved part. Purchasing bought them and patted themselves on the back for sving almost 50%, but the new 5% parts caused problems that we had never had with the specified 10% parts. No one bothered to compare the SRF, and the new, unapproved vendor line was about 20% lower, across the range that we needed. Purchasing got their asses chewed out by the head of engineering and one of the Corporate VPs, over that blunder.


Michael A. Terrell

On 29 Jul 2018, at 10:39, Michael A. Terrell <mike.terrell@...> wrote:

The failures I saw with the Beckman pots were in telemetry receivers being built for NASA. They were the ones in use when we lost that last shuttle. The media was waiting for information, but when you had built the equipment for the earth stations, with dual diversity at every tracking site I knew as soon as they stated, We have a loss of telemetry' that we had lost another shuttle. It was like a kick in the gut, hoping for the impossible in that six complete systems had failed at the same instant instead of the loss of the shuttle.

We couldn't wait for Beckman to decide that we were right, because our products were used by many Aerospace companies where failures could cost hundreds or thousands of lives. They forced us to make the change, and only by removing a company from the master Approved Vendor List could we make sure that no one substituted anything else. Purchasing was then forced to state 'NO SUBSTITUTIONS ALLOWED ON THIS ORDER'.

As an example, a distributor offered purchasing some tighter tolerance molded inductors for a lower price than the approved part. Purchasing bought them and patted themselves on the back for sving almost 50%, but the new 5% parts caused problems that we had never had with the specified 10% parts. No one bothered to compare the SRF, and the new, unapproved vendor line was about 20% lower, across the range that we needed. Purchasing got their asses chewed out by the head of engineering and one of the Corporate VPs, over that blunder.


Michael A. Terrell


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

From: Adrian <Adrian@...>
Sent: Jul 29, 2018 4:54 AM
To: [email protected]
Subject: Re: [TekScopes] Slightly OT - Bourns trimmer pot failure

Yup, you could be right, I just looked at a copy of the datasheet I
found on the web. The strap line in the sheet is "Now you can specify
Bourns for cost-sensitive applications" the sheet is marked 1977 but it
is over-stamped with "Obsolete" dated 79 so this design wasn't around
long, that may say something about the design? Certainly compared with
the lifetime of products like the 3386 which I also used in large
numbers at one point in my life with no issues.

I agree, why do people have such an issue with owning up to a problem? I
spent a fair part of my life in aerospace world and there the culture is
different - Problem? 'share early, share often' - was the mantra in
Boeing and it worked, genuine 'no blame' culture. S**t happens, what
matters is you truly understand root cause and fix it, that way we don't
kill a bunch of folks (which could include our family members, as we
were oft reminded) sitting in a tube at 35,000 ft!

On 7/29/2018 8:47 AM, M Yachad wrote:
So, crap like that happens every so often - I haven't boycotted Bourns over that - their quality is usually excellent - and it would be nice if the manufacturer would 'fess up, without dancing around an issue which is plain as day for anyone to see.

From: "[email protected] Notification" <[email protected]>
To: [email protected]
Sent: Sunday, July 29, 2018 2:44:43 PM
Subject: [TekScopes] New file uploaded to [email protected]

Hello,

This email message is a notification to let you know that a file has been
uploaded to the Files area of the [email protected] group.

*File:* Replacing Electrolytic Filter Capacitors in a Tektronix 465.pdf

*Uploaded By:* n4buq

*Description:*
Step by step procedure for replacing the electrolytic capacitors in a 465B
using an auxiliary board with snap-in capacitors.

You can access this file at the URL:
/g/TekScopes/files/Replacing%20Electrolytic%20Filter%20Capacitors%20in%20a%20Tektronix%20465.pdf

Cheers,
The Groups.io Team

-----Original Message-----
From: Ke-Fong Lin
Sent: Sunday, July 29, 2018 12:19 PM

Hi everyone,

The fan of my TM5003 is a bit loud and it has a "rattling" component into
it.
This is not as bad as a TM5006, but still quite loud.
That would be ok for a professional or industrial setting, but not for my
home bench in a basement.

Photos are here: /g/TekScopes/album?id=65073

In fact, TM5003 and TM5006 use the same fan model: a 75CFM at 115VAC (Tek
part 119-0721-00), see service manuals.
However, TM5006 with racking options (option 12), uses a 105CFM instead.
So it is quite over-rated for the TM5003 which has only 3 slots, versus the
5 "regular" slots plus 1 high powered compartment of the TM5006.
And I guess we can without issue use a 50CFM fan instead, that's still 2/3
of 75.

I managed to find an almost exact match (~76CFM at 50Hz and ~67CFM at 60Hz),
but with lower noise of course (32db) :



The swap was actually quite easy, just unscrew everything, unplug the fan
wires.
Cut the wires from the old fan, resolder to the new one. Plug back
everything, fasten all screws.
See photos.

The end result is a bit mixed :(

It is a bit quieter, in particular, the rattling component of the fan noise
is gone. That's a new fan after all!

However, I thought that 32db was quieter than that.
To give you an idea, the noise is now about the same as a loud desktop PC
with all its fans at max speed.
I must have read something wrong about how quiet 32db is.
Maybe my expectation were too much.
Or the replacement fan doesn't meet its 32db specification!
Or a mix of all of the above :)

The original fan is from "Whisperer" brand. And it is indeed quieter than
the TM5006 I've owned It has a May 92 date on it, so my TM5003 is not that
old.

Probably, the biggest issue, is that the fan is not temperature controlled.
So it always runs at max speed, moving tons of air.

All in all, there is still some improvement, so I'm happy. And I had fun.
If I were to do it again, I'll probably go for a 50CFM from a more "high
end" brand (ebm papst?)

Best regards,

From: "Paul Amaranth" <paul@...>
To: [email protected]
Sent: Thursday, July 26, 2018 9:57:14 AM
Subject: Re: [TekScopes] Replacing Electrolytics in a 465/465B

Another method that works well is to use individual adapter
boards for each cap. The boards are roughly the same diameter
as the original caps and allow a modern snap cap to be used.

You can make the patterns up in any drawing program if you want
to etch your own, gerbers are floating around the web and
they are available on ebay once in a while. The boards work
out to be around $1 or less each if you use one of the cheap board
houses.

If you use long leads on those, you can thread the cap in without
having to disassemble the scope.

That method seems to have been independently invented four or five
times that I'm aware of (and probably many more).

Paul

-----Original Message-----
From: n4buq <n4buq@...>
To: TekScopes <[email protected]>
Sent: Wed, Jul 25, 2018 1:05 am
Subject: [TekScopes] Replacing Electrolytics in a 465/465B

Recently, I had a problem with the LV supplies in my 465B. Thinking it was
a
shorted electrolytic can, I decided to replace all of them (although it
turned out to be a shorted tantalum but had already pulled the cans before
finding the real problem).

I decided to design a small PC board on which to mount modern snap-in caps.
THe board mounts with standoffs in the exising larger holes that are left
when the cans are removed and allow replacement of the snap-ins if/when
they
fail and that can be done without further soldering on the original board.

Pictures of the board and the process are in the following album:

/g/TekScopes/album?id=64929

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows

The flux fumes will go right through the fiber disk.
I use a Pace desoldering system with a cotton like plug in the solder capture
cylinder and a fiber filter at the end of the tubing just before it goes into the
vacuum pump.
The fiber filter catches a lot but not all of the vapor.
A lot of the flux vapor condenses out onto the inside wall of the tubing connecting
the iron to the vacuum pump.
The installed vacuum pump here is a rotary vane pump.
About once a year, I have to disassemble the pump and clean the carbon vanes and the
carbon wear plates to remove the condensed flux vapor.
The amount of flux vapor ingested by the system is based on the amount of residual
flux left on the solder being removed and the length of time that you are sucking the
solder in one session.
The hotter the air through the system the more vaporized flux gets to the pump.
If you only remove a few parts then let the system rest and the solder capture
cylinder cool down there is less flux vapor than if you desolder a large quantity of
parts at one time.
I do the latter and have recovered over 20 pounds of solder from boards.

Glenn

On 7/29/2018 10:51 AM, John Griessen wrote:

On 07/29/2018 06:18 AM, Mark Wendt wrote:

The Hakko desoldering station I have has two sets of inline filters. One, a kind
of springy thingy for stopping the solder bits and pieces from flowing into the
pump, and the other a fiber disc for stopping the smokey stuff from getting
through. Perhaps on John's system the fiber disc isn't in place to stop that from
happening?

It's in place. It's not enough though.

-----Original Message-----
From: n4buq <n4buq@...>
To: TekScopes <[email protected]>
Sent: Wed, Jul 25, 2018 1:05 am
Subject: [TekScopes] Replacing Electrolytics in a 465/465B

Recently, I had a problem with the LV supplies in my 465B. Thinking it was a
shorted electrolytic can, I decided to replace all of them (although it
turned out to be a shorted tantalum but had already pulled the cans before
finding the real problem).

I decided to design a small PC board on which to mount modern snap-in caps.
THe board mounts with standoffs in the exising larger holes that are left
when the cans are removed and allow replacement of the snap-ins if/when they
fail and that can be done without further soldering on the original board.

Pictures of the board and the process are in the following album:

/g/TekScopes/album?id=64929