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A resurrected 465 parts scope.


Dave Peterson
 

It's not exactly refurbished quality yet, but I think I've managed to bring it back to life.

I picked this 465 up from a local eBay listing, so I didn't have to pay shipping. It was a nice drive over the San Mateo bridge one morning during Thanksgiving break.

I had it back up after replacing the shorted C1419/C1418 cap pair, but it died again shortly after due to a PS cap failure. The total issues repaired so far are the C1419/C1418 and F1419 HV supply filter and fuse, replacement of a broken B DLY'D push button switch, epoxy repair of the B TIME/DIV cam and knob body, and finally all 5 power supply caps.

Otherwise I've disassembled the face and thoroughly cleaned everything - including some of the push button text right off. Doh! Thanks Jeff Dutky for the replacement push buttons! He also provided me with a missing B trigger slope switch. Some remaining superficial issues are a slightly damaged CH1 VOLTS/DIV text (10, 20, 50), and the CH2 1x light is out/intermittent.

I've gone through the calibration procedure best I can with my limited tools. I can't assure that it's tuned to spec at full bandwidth, but I was able to tune it well enough that CH1 & CH2 levels are consistent and within spec (to the levels I have at hand), and the A and B sweep timing appears good to at least 25MHz.

I posted a pic of the finished product in my 465 PS cap replacement photo album: https://groups.io/g/TekScopes/album?id=258720

The waveform is both CH1 and CH2 overlapping showing that it's making nice clean traces.

I know it's just another 465, but I'm happy that I was able to bring one back to life. I think this one's a keeper.

Dave


adesilva_1999@...
 

Nice job Dave!


 

Dave,

It's a beautiful scope. I'm glad I could contribute to its rehabilitation.

-- Jeff Dutky


 

On Sat, Jan 9, 2021 at 07:19 AM, Dave Peterson wrote:


Otherwise I've disassembled the face and thoroughly cleaned everything -
including some of the push button text right off. Doh! Thanks Jeff Dutky for
the replacement push buttons!
I usually clean these push buttons with grease, like ordinary butter(!). That usually saves the text, especially if done carefully.

Raymond


 

Nice job and photos Dave.

I should ask about your replacement capacitors, and whether you had to employ adapter boards, as my trusty 465 may be operating on borrowed time.

Bruce,


Dave Peterson
 

Thanks all for your encouragement and help. I might have been able to do it myself, but: a) it wouldn't have turned out half as well, b) it wouldn't have been half as fun.

Butter!? "It's a desert toping AND a floor polish!" Sorry, couldn't help myself. :^)

Bruce,

Yes, I used the adapter boards recommended by Michael Lynch in Ed Pavlovic's "Tek 465 Negative 8 volt rail issues" thread: https://groups.io/g/TekScopes/message/175363 In that thread I detailed some of the analysis I did and conclusions I came to regarding PS caps. I tend to be long winded, but I'm just hoping to be as comprehensive as I can. I'll go ahead and drop this list of Nichicon caps I ordered from Mouser:

C1512, 560uF: UCY2C561MHD, 560uF, 160v, 2130mA, 18mmx40mm, 7.5mm lead spacing.
C1513, 1200uF: LGN2C122MELA40, 1200uF, 160v, 2300mA, 25mmx40mm, 10mm lead spacing.
C1542, C1552, C1562, 5600uF: LGY1H562MELA40, 5600uF, 50v, 2300mA, 25mmx40mm, 10mm lead spacing.

Michael's eBay recommendation:
eBay item number:
273254508468

Seller information:
cuog (749 )
100% Positive feedback

And look up the "465 Power Supply Capacitor Replacement Guide" in the Files section. You can find pictures of the new caps with the adapter boards attached in the same photo album as the finished product linked in the OP. I'm happy to share any details you might have questions about.

Again, thanks to all.
Dave


 

On Sat, Jan 9, 2021 at 04:48 PM, Dave Peterson wrote:


Butter!? "It's a desert toping AND a floor polish!" Sorry, couldn't help
myself. :^)
Yep,
It's as ridiculous and risky as washing old (tube) Tek 'scopes using water, as Tek itself did.
It was safe if done correctly and did the job well.

Raymond


Harvey White
 

Good Heavens, man, think of your diet!

You should use low fat margarine instead.

Harvey

On 1/9/2021 11:21 AM, Raymond Domp Frank wrote:
On Sat, Jan 9, 2021 at 04:48 PM, Dave Peterson wrote:

Butter!? "It's a desert toping AND a floor polish!" Sorry, couldn't help
myself. :^)
Yep,
It's as ridiculous and risky as washing old (tube) Tek 'scopes using water, as Tek itself did.
It was safe if done correctly and did the job well.

Raymond





 

Thanks again Dave for taking time to provide the detailed listing of 465 replacement caps and adapter boards. I have ordered a set of the boards and will keep your parts list on hand for that inevidable day when the screen goes dark.

I clearly remember my first encounter with the 465. In about 1970, my workplace was in the process of ordering a Sony-Tektronix portable when the Tek rep whispered that we should hold tight for a couple of weeks for a revolutionary new product. The 465 was announced and we quickly bought one. Of course it was years later before I acquired one for home use, but by then it was a familiar old friend.

Bruce, KG6OJI


Dave Peterson
 

One of the apparent consequences of the PS cap replacement is it now takes about 5 seconds for a trace to come up. Just tested it cold and warm. Both take about 5 seconds. I did not take note of the original wake up time before the original PS caps gave out, so I've lost that piece of information. Didn't consider it at the time.

My existing scope (with original PS caps) takes about 3 (or less) overnight cold. Not testing warm (yet) because I'm about to crack it open and start its "restoration".

I can imagine a few possibilities:
- Just natural differences in scopes, tuning, age, use, ...
- The native PS caps in the faster wake up scope are degrading and exhibit less available capacitance, higher internal R, both, etc. PS rails come up faster.
- The new slightly larger caps (in the 110v/55v case), or a bit larger in the -8v case (5600uF - 3000uF), slow the PS rails wake up time.

Just an observation. I'm considering making a further more detailed study of available caps on Mouser and perhaps trying a set more closely matched to original values.

Any experiences and/or thoughts regarding this?

Dave


Michael W. Lynch
 

On Sat, Jan 9, 2021 at 04:34 PM, Dave Peterson wrote:


One of the apparent consequences of the PS cap replacement is it now takes
about 5 seconds for a trace to come up. Just tested it cold and warm. Both
take about 5 seconds. I did not take note of the original wake up time before
the original PS caps gave out, so I've lost that piece of information. Didn't
consider it at the time.
Dave,

I have 8 various 4xx series sitting here, all in the same room. Out of curiosity, after reading your post, I just turned them on (one at a time) and timed each scope as it "warmed up" to display a trace. This varied group of scopes, one or two with all new caps, two with only one cap replaced and the rest running on OEM caps. All these 8 scopes show a normal trace from 6-9 seconds after the power switch is turned on. My 485 seems slowest, the 475A and 475 are next, followed by the 465 and 465B and finally (and strangely) the 468's seem fastest of the group. None showed a trace in anything close to 3 seconds. These are all set for "normal" viewing intensity. I would imagine that the cathode of the CRT takes longer to actually heat up and produce the electron beam than those caps could possibly take to charge or the supplies to stabilize? This is just an anecdotal observation of my group of scopes.
--
Michael Lynch
Dardanelle, AR


Dave Peterson
 

Nice Michael. Thanks for the data points. Makes me feel much better about the "slow down" I perceived. Perception corrected.
Good point about the cathode heater time too. Yes, that makes sense that cathode heating is going to take much longer than filter cap charge up. Seconds vs. milli or even micro seconds.
You guys rock.Dave

On Saturday, January 9, 2021, 03:04:10 PM PST, Michael W. Lynch via groups.io <mlynch003=yahoo.com@groups.io> wrote:

On Sat, Jan  9, 2021 at 04:34 PM, Dave Peterson wrote:


One of the apparent consequences of the PS cap replacement is it now takes
about 5 seconds for a trace to come up. Just tested it cold and warm. Both
take about 5 seconds. I did not take note of the original wake up time before
the original PS caps gave out, so I've lost that piece of information. Didn't
consider it at the time.
Dave,

  I have 8 various 4xx series sitting here, all in the same room.  Out of curiosity, after reading your post, I just turned them on (one at a time) and timed each scope as it "warmed up" to display a trace.  This varied group of scopes, one or two with all new caps, two with only one cap replaced and the rest running on OEM caps. All these 8 scopes show a normal trace from 6-9 seconds after the power switch is turned on.  My 485 seems slowest, the 475A and 475 are next, followed by the 465 and 465B and finally (and strangely) the 468's  seem fastest of the group.  None showed a trace in anything close to 3 seconds.  These are all set for "normal" viewing intensity.  I would imagine that the cathode of the CRT takes longer to actually heat up and produce the electron beam than those caps could possibly take to charge or the supplies to stabilize?  This is just an anecdotal observation of my group of scopes.
--
Michael Lynch
Dardanelle, AR


 

Dave,

Have you checked your HV? One of the telltales when I got the HV in spec on my 475A was that the screen came up a couple seconds faster than it had when the HV was down 20%.

-- Jeff Dutky


Dave Peterson
 

Good point. I've been thinking about it, but haven't needed it yet as much as a lot of other basic stuff. Still a lot of basic stuff to get, but if I'm going to make a hobby of this an HV probe is a basic thing too.
I have to remind myself I've been at this all of a couple of months, if that. All in good time.
Is there a corollary law to Moore's Law regarding # of oscilloscopes owned? It's a scary thought considering I doubled the number I owned in a month. And have potentially more in the pipeline already. What have I gotten myself into?
Dave

On Saturday, January 9, 2021, 04:28:35 PM PST, Jeff Dutky <jeff.dutky@gmail.com> wrote:

Dave,

Have you checked your HV? One of the telltales when I got the HV in spec on my 475A was that the screen came up a couple seconds faster than it had when the HV was down 20%.

-- Jeff Dutky


Tom Lee
 

Just let nature take its course and enjoy the exponential. :)

--Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 1/9/2021 17:47, Dave Peterson via groups.io wrote:
Good point. I've been thinking about it, but haven't needed it yet as much as a lot of other basic stuff. Still a lot of basic stuff to get, but if I'm going to make a hobby of this an HV probe is a basic thing too.
I have to remind myself I've been at this all of a couple of months, if that. All in good time.
Is there a corollary law to Moore's Law regarding # of oscilloscopes owned? It's a scary thought considering I doubled the number I owned in a month. And have potentially more in the pipeline already. What have I gotten myself into?
Dave

On Saturday, January 9, 2021, 04:28:35 PM PST, Jeff Dutky <jeff.dutky@gmail.com> wrote:
Dave,

Have you checked your HV? One of the telltales when I got the HV in spec on my 475A was that the screen came up a couple seconds faster than it had when the HV was down 20%.

-- Jeff Dutky









 

Dave,

The number of scopes owned is a direct measure of entropy.

My stable has increased since November, now I not only have parts mules for my fathers 475 and 2213 (a couple 2215As as mules for the 2213), but I also have a 2236 (and a 2235 as a parts mule), a 5103N (with a small assortment of modules, and another 5103N mule on the way), and just today I received a 2465 DMS. I also have several 500-series modules for a TM503.

No. I don't have a problem.

-- Jeff Dutky


Jim Ford
 

The only problem I have is that I have to keep my scope and other test equipment buying to a minimum to keep the peace in the house!  I'm at 4 scopes and unfortunately no parts mules (yet).  Did buy a bunch of probes late last year.  Now I just (yeah, right!) need "witches' hats" and ground leads for them all.    Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Jeff Dutky <jeff.dutky@gmail.com> Date: 1/9/21 6:09 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] A resurrected 465 parts scope. Dave,The number of scopes owned is a direct measure of entropy.My stable has increased since November, now I not only have parts mules for my fathers 475 and 2213 (a couple 2215As as mules for the 2213), but I also have a 2236 (and a 2235 as a parts mule), a 5103N (with a small assortment of modules, and another 5103N mule on the way), and just today I received a 2465 DMS. I also have several 500-series modules for a TM503.No. I don't have a problem.-- Jeff Dutky


 

Jim,

Ground leads and witches' hats for the regular modular probes (e.g. P6075 or P6106) don't seem to be hard to come by (if you'll accept new, Chinese-made ones), but both are like hen's teeth for the miniature modular probes (e.g. 6120/21/22). I'm not even sure why; the witches' hats look almost identical to the normal kind, but obviously aren't. Why they went with that ground lead, with the tubular connector, I'll never understand: it just makes the ground loop even longer.

-- Jeff Dutky


adesilva_1999@...
 

I had this 465M for over 20 years now. Got it for $100 at a swap meet. Never used it that much but while troubleshooting my friend's guitar amp, blew the EHT module by leaving it ON overnight accidentally. While in the process of fixing it, there was a nearby bloke selling a 465 for $100 and I thought it was too good to pass off as I was not sure if the 465M would ever come back to life. It came with no front cover nor the manual. Spent another $35 bucks for those on eBay. In the midst of all this, a good soul was giving away a 2215 and I had it collected by a friend but I am yet to get my hands on it as my friend lives far up north.
With help from the guys at EEVBlog, I was able to fix the 465M (created a completely new EHT block that is not a simple multiplier!). A few days back, I fixed the 465 which had a stupid little loose connection at the CH2 input and gave it away to my friend who has the guitar amp. Hopefully, when he goes back to his home country some day, he can rely on it for his hobby work.
At the moment since I don't do much repair work or projects, I am happy to hang on to the 465M which is pretty easy to take apart and repair in case it is necessary. Not decided what to do with the 2215 yet!
One thing for sure. No more buying for me. No space and getting too old!


Jim Ford
 

True, Jeff.   I have four P6106As, three P6102As, and one P6105A, with just one witch's hat and one ground lead among them.  Plus a P6139A and two HP probes to go with my HP 54504A digital scope.  If I can't bum or buy a few parts from my friend who runs the Wireless Lab at Broadcom where I used to work and deals in test equipment on the side, it shouldn't be too hard to find them on eBay .   Thanks.  JimSent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Jeff Dutky <jeff.dutky@gmail.com> Date: 1/9/21 6:48 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] A resurrected 465 parts scope. Jim,Ground leads and witches' hats for the regular modular probes (e.g. P6075 or P6106) don't seem to be hard to come by (if you'll accept new, Chinese-made ones), but both are like hen's teeth for the miniature modular probes (e.g. 6120/21/22). I'm not even sure why; the witches' hats look almost identical to the normal kind, but obviously aren't. Why they went with that ground lead, with the tubular connector, I'll never understand: it just makes the ground loop even longer.-- Jeff Dutky