Date   

Tektronix 2465. Odd wave pattern superimposed on waveforms.

John Osborne
 

Greetings to all.
I have recently purchased a non-working Tektronix 2465 (not A or B). Having carefully recapped the power supply which was blowing fuses due to leaky mains input filter capacitors I am left with an unusual fault.

The scope displays a good sine wave on all inputs. But superimposed on the perfect sine wave is a rippling wave that travels from right to left in quick succession. Perhaps 6 waves per second. It does not distort the sine wave in any way but travels along the wave on both the top and bottom edge of the trace. The wave is much lower in intensity than the sine wave displayed but is very noticeable.
Perhaps a common issue so please excuse me as I am new to this group.

Many thanks and best wishes to all.

John


Help with a TEK 502 scope HV transformer

jrodriguezcsb@...
 

Dear all,

I am new in this group, so I would like to greet all of you.

I am restoring an old tek 502 scope.
I have change death tubes, and check everything and now it powers up. Power supply works, fan works, everything seems to work except the HV power supply.
Its CRT looks like new, it has good heater and has not lost its vacuum.

However, the HV flyback transformer has a shorted winding and it makes sparks - really nice for a chritsmas tree but, definetely, not for a tek scope.
I have been doing a bit of research and I realize it has the same trafo as a tek 502A scope (I do not know why). In fact, it has 3 rectifier tubes.

The option I see are:
1. Acquire a new working transformer. If any of you has one and wants to sell it, I am interested.
2. Restoring it. As it is cover in wax, it semms difficult not to brake this little wire.
3. Manufacturing a new one. I do not know how to do it, so I would need your help.

Here I would need your help to continue with the restauration. How would you solve this problem?

Waiting for your help!!
Thanks a million!
PS_1. If you tell me how, I would upload here several pictures of it.
PS_2. I have write another post with the same info, but I lost it. Forgive me, it is my first day here : )


Help with a TEK 502 scope

jrodriguezcsb@...
 

Hi to all,

I am new in this forum, a friend of mine tell me about a group of wise nice people.

I am restoring an old tek 502 tube scope. And I need some help: Its HV transformer is death, it has a burned winding and it makes sparks - really nice for a christmas tree but not for a scope, defenetely : (
I have been investigating a little bit and I realise that the CRT transformer of my TEK502 is indeed the same that the tek502A, it has 3 rectifier tubes instead of two. Maybe they change it at the middle of production time.
The rest of the scope is in good shape, its CRT is almost new, its power supply caps are like new as well and I change death tubes for NOS ones. So, lets say its like a brand new blind scope.

So I would need your help. From my point of view the options are:
1. Buy a working HV transformer. If any of you have one and want to sell it, I am interested.
2. Restore it. It is cover by wax, so it would be difficult not to break the little wires.
3. Manufacturing a new one. I have no idea how many turns it has, wire diameter...

I am really interested in learning and, if possible, helping other forum partners. So, where do we start?

Waiting for your answers.
Thanks a million guys!!

PS. I do not know how to post images, if any of you say me how i will upload several pictures of the scope.


What removes sticker residue without hurting the blue paint?

 

A far too common problem I have no solution for yet:

What will remove sticker residue on Tek blue paint without harming the paint
finish?



Stay away from GOOF OFF. Its active ingredient is XYLENE, which dissolves
paint very quickly. Don't ask me how I know :(



Isopropyl alcohol is very mild on most things but it does poorly against the
sticker residue and often you have to rub the affected area to get the glue
to come off. The rubbing removes some blue paint and mars the finish so that
is no good.



Would boiling water soften the sticker residue and leave the paint alone or
would it siften the paint as well.



Suggestions are welcome.


Re: Off Topic: Wanted Spectracom 8212 Chart Recorder Manual

 

The manual has been uploaded to Didier's site (http://www.ko4bb.com/getsimple/index.php?id=manuals) and to the TekWiki site (http://w140.com/tekwiki/wiki/Spectracom_8212).

Enjoy!!
Dave M


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

Artekmedia <manuals@...>
 

NOTHING TO READ ABOVE ????

On 6/11/2018 5:52 PM, John wrote:
Sorry, for -12V read +12V above.



--
Dave
Manuals@...
www.ArtekManuals.com


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

John
 

Sorry, for -12V read +12V above.


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

John
 

I've tackled a couple of 453 EHT problems. In one case (actually a 454) it was the final HV capacitor (before the CRT anode) which had broken down. In the other instance, it was a thermally-related runaway problem with the transformer. It would take increasing current as it heated up until the -12V line was affected. A third 'scope had a gassy tube, which resulted in a purple glow in the neck and excessive EHT current. You can elimiate this from your enquiries by (carefully! discharge first) lifting the anode output lead and re-powering. Is your scope fitted with 5642 tubes or silicon rectifiers?


Re: noticed: Tek 836 Programmable Comm tester on eBay

Dave Seiter
 

I got one of those in a pallet lot years ago- it seemed to work perfectly, but I had to practically give it away.  
-Dave

From: garp66 <@green>
To: TekScopes@groups.io
Sent: Monday, June 11, 2018 2:27 PM
Subject: [TekScopes] noticed: Tek 836 Programmable Comm tester on eBay

Perhaps of use to someone ?

Tek 836 Prog. Comm. tester.
~$58  Or  Make an Offer

https://www.ebay.com/itm/Tektronix-Programmable-Communications-Tester-Model-836-Tested-OTT/263743613926?hash=item3d68582be6:g:tucAAOSw90xaulKj


noticed: Tek 836 Programmable Comm tester on eBay

garp66
 


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

RustySparks
 

Yes, my 453A also has vacuum tube rectifiers, and a non-potted HV transformer. I really went through the whole HV supply until there simply was nothing else to blame except the transformer, before finally giving up to the very unwelcome realization that the HV transformer was bad in the scope I had used since it was new. Very sad indeed.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of william_b_noble
Sent: Monday, June 11, 2018 2:55 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] let's bring this back to life Re: Tektronix 453 high voltage problem

The reason I don't think that the transformer epoxy is going bad is because the transformer is not potted at all. I can see the windings. My understanding is that later transformers were potted. I have the early style supply with the vacuum tubes for the 12kV high voltage doubler.


Re: OT: Old ICs for sale

Dave Seiter
 

When I first started selling, just about anything listed was sold in the first or second attempt.  I stopped selling for a long time because they dinged you for everything, and the huge volume of items meant that some things just wouldn't sell- I was losing money.  It wasn't until you could list for free that I went back to selling.
-Dave

From: Daniel Koller via Groups.Io <kaboomdk=yahoo.com@groups.io>
To: "TekScopes@groups.io" <TekScopes@groups.io>
Sent: Monday, June 11, 2018 11:35 AM
Subject: Re: [TekScopes] OT: Old ICs for sale

Ditto here.  I haven't had a serious bidding war on any item I've sold in years either.  I financed my hobby budget in grad school by selling old junk vacuum equipment and old Tek stuff and it used to be worthwhile to sell it.  As e-bay popularity increased, I suppose more competition grew, and also large surplus sellers came on-board, which is great for buyers, not so much for individual sellers.  Fees also increased, and for that matter, shipping is through the roof now.    
But I also don't "bid" now.  I always "snipe" (with auctionsniper).   That lets me think about the price I think the item is "worth" and what I am willing to pay for it in a calm, rational environment.  I set the desired price and walk away.  If I get it for a low bid, great, and if I go to the maximum, at least I don't end up regretting it immediately.
  Dan

    On Monday, June 11, 2018, 2:14:00 PM EDT, Dave Seiter <d.seiter@...> wrote:

A bidding war hasn't happened to any of my listings for years, but yeah, it's so much fun to watch!  These days, it's usually only rare items that end up in bidding wars, but certain categories see more activity than others.  Another fun event is having two or more people snipe with "silly" bids at the last second.
-Dave

      From: Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
To: TekScopes@groups.io
Sent: Monday, June 11, 2018 10:50 AM
Subject: Re: [TekScopes] OT: Old ICs for sale
 
Hi Tom, and everyone who bids on Ebay,

There is some misunderstanding about prices on Ebay: Newbies and or sellers with stores frequently list their items with arbitrarily high prices. Sometimes they simply look at current listings and price accordingly.

BUT what really matters is what these items SOLD for. To find that out you have to look carefully through the completed listings for the auctions that were successfully concluded.

That will tell you the true price the market thinks this is worth.

If there is an outlier in the completed auctions that sold for a truly outrageous price you have to look at the bidding that took place. It was probably between two newbies that didn't understand how Ebay works and they kept outbidding each other by a few dollars each time. If you are a seller you always hope your item will be bid up by newbies to absurd prices. It is lots of fun to watch one of these bidding wars take place and wonder where it will end.

Dennis Tillman W7PF

-----Original Message-----
From: Tom Gardner Sent: Monday, June 11, 2018 12:43 AM

On 11/06/18 05:19, G Hopper wrote:
I suppose that for $55 there probably is some value in that offering
even if some of the chips are dead.  I do have to chuckle since I have
some of the same stuff as NOS in my parts drawers and amongst the
boxes I've inherited from others.  Never really considered the
possibility that any of it had value.  "There's gold in them there
drawers!!!!"

Perhaps more than you might think - and they don't even have to be
unused. Look at the fleabay prices for "mustard capacitors" and
"germanium transistor"



--
Dennis Tillman W7PF
TekScopes Moderator


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

Phillip Potter
 

Wow, then I will guess that my manual isn’t appropriate, sorry!

Phil, N6OMM

On Jun 11, 2018, at 12:55 PM, william_b_noble <william_b_noble@...> wrote:

I have the early style supply with the vacuum tubes for the 12kV high voltage doubler.


Re: OT: Old ICs for sale

Dave Seiter
 

I can't count the number of times I've boxed up something and then ended up stuffing the whole thing into a flat rate padded envelope to save 50% or more on shipping.  Keeping shipping down is the biggest challenges these days.
-Dave

From: John Griessen <@jgriessen>
Lots of things can go in flat rate USPS envelopes stuffed to resemble a football.  -=-=-=-=-=-=-=-=-=-=-=-


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

Dave Wise
 

A winding can impregnated with epoxy without being potted in it. I restored my early 453 by rewinding, and it wasn't potted. See topic and photo album titled "453 HV Transformer Rewind".

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of william_b_noble <william_b_noble@...>
Sent: Monday, June 11, 2018 11:55 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] let's bring this back to life Re: Tektronix 453 high voltage problem

The reason I don't think that the transformer epoxy is going bad is because the transformer is not potted at all. I can see the windings. My understanding is that later transformers were potted. I have the early style supply with the vacuum tubes for the 12kV high voltage doubler.


Re: let's bring this back to life Re: Tektronix 453 high voltage problem

william_b_noble
 

The reason I don't think that the transformer epoxy is going bad is because the transformer is not potted at all. I can see the windings. My understanding is that later transformers were potted. I have the early style supply with the vacuum tubes for the 12kV high voltage doubler.


Re: OT: Old ICs for sale

Daniel Koller
 

Ditto here.  I haven't had a serious bidding war on any item I've sold in years either.  I financed my hobby budget in grad school by selling old junk vacuum equipment and old Tek stuff and it used to be worthwhile to sell it.  As e-bay popularity increased, I suppose more competition grew, and also large surplus sellers came on-board, which is great for buyers, not so much for individual sellers.  Fees also increased, and for that matter, shipping is through the roof now.    
But I also don't "bid" now.  I always "snipe" (with auctionsniper).   That lets me think about the price I think the item is "worth" and what I am willing to pay for it in a calm, rational environment.  I set the desired price and walk away.  If I get it for a low bid, great, and if I go to the maximum, at least I don't end up regretting it immediately.
  Dan

On Monday, June 11, 2018, 2:14:00 PM EDT, Dave Seiter <d.seiter@...> wrote:

A bidding war hasn't happened to any of my listings for years, but yeah, it's so much fun to watch!  These days, it's usually only rare items that end up in bidding wars, but certain categories see more activity than others.  Another fun event is having two or more people snipe with "silly" bids at the last second.
-Dave

      From: Dennis Tillman W7PF <@Dennis_Tillman_W7pF>
To: TekScopes@groups.io
Sent: Monday, June 11, 2018 10:50 AM
Subject: Re: [TekScopes] OT: Old ICs for sale
 
Hi Tom, and everyone who bids on Ebay,

There is some misunderstanding about prices on Ebay: Newbies and or sellers with stores frequently list their items with arbitrarily high prices. Sometimes they simply look at current listings and price accordingly.

BUT what really matters is what these items SOLD for. To find that out you have to look carefully through the completed listings for the auctions that were successfully concluded.

That will tell you the true price the market thinks this is worth.

If there is an outlier in the completed auctions that sold for a truly outrageous price you have to look at the bidding that took place. It was probably between two newbies that didn't understand how Ebay works and they kept outbidding each other by a few dollars each time. If you are a seller you always hope your item will be bid up by newbies to absurd prices. It is lots of fun to watch one of these bidding wars take place and wonder where it will end.

Dennis Tillman W7PF

-----Original Message-----
From: Tom Gardner Sent: Monday, June 11, 2018 12:43 AM

On 11/06/18 05:19, G Hopper wrote:
I suppose that for $55 there probably is some value in that offering
even if some of the chips are dead.  I do have to chuckle since I have
some of the same stuff as NOS in my parts drawers and amongst the
boxes I've inherited from others.  Never really considered the
possibility that any of it had value.  "There's gold in them there
drawers!!!!"

Perhaps more than you might think - and they don't even have to be
unused. Look at the fleabay prices for "mustard capacitors" and
"germanium transistor"



--
Dennis Tillman W7PF
TekScopes Moderator


Re: OT: Old ICs for sale

John Griessen
 

On 06/11/2018 12:28 PM, Dave Seiter wrote:
Selling items is better than watching TV, and if they get used, it's better than dumping them in landfill
Yes, I have a scale that goes to 5kg and a squirt bottle of diluted wood glue for putting laser printed labels on
packages. Lots of things can go in flat rate USPS envelopes stuffed to resemble a football. First class package rate for a padded bubble mailer under a pound is a good way.
It helps to be near a source of cardboard boxes. When I gather boxes from local
retailers 130 feet from my door, I often get good packing material too. I use an old Canon S30 for photos because it gets good exposures and focuses well, and makes photos about 2400 pixels across -- not too large so they quickly can be fixed up in GIMP photo editing tool. Instead of cables to the camera, I remove and replace its compact flash card, (about 3 x 4 cm), and use that with a dedicated compact flash card reader. That all makes for a fairly quick round trip of photo shooting to serving up on a web site (craigslist or ebay).


Re: OT: Old ICs for sale

JJ
 

Good info - wasn't aware of those links.
Thx Tom
Best,
John Justin

On Mon, Jun 11, 2018 at 2:17 PM, Tom Gardner <tggzzz@...> wrote:

On 11/06/18 18:50, Dennis Tillman W7PF wrote:

Hi Tom, and everyone who bids on Ebay,

There is some misunderstanding about prices on Ebay: Newbies and or
sellers with stores frequently list their items with arbitrarily high
prices. Sometimes they simply look at current listings and price
accordingly.

BUT what really matters is what these items SOLD for. To find that out
you have to look carefully through the completed listings for the auctions
that were successfully concluded.
Indeed, but care isn't needed: just select "sold listings" :)

There are a couple of other useful tools for buyers:

- to find out what an "or best offer" actually sold for, use
http://www.watchcount.com/ and paste in the item's number (as found
buried in the URL)

- to find out what offers a seller has accepted/rejected, use
https://www.goofbid.com/ebay_best_offers_tool.html# with the seller's name

That will tell you the true price the market thinks this is worth.

If there is an outlier in the completed auctions that sold for a truly
outrageous price you have to look at the bidding that took place. It was
probably between two newbies that didn't understand how Ebay works and they
kept outbidding each other by a few dollars each time. If you are a seller
you always hope your item will be bid up by newbies to absurd prices. It is
lots of fun to watch one of these bidding wars take place and wonder where
it will end.
Try watching the live online auctions!

Dennis Tillman W7PF

-----Original Message-----
From: Tom Gardner Sent: Monday, June 11, 2018 12:43 AM

On 11/06/18 05:19, G Hopper wrote:

I suppose that for $55 there probably is some value in that offering
even if some of the chips are dead. I do have to chuckle since I have
some of the same stuff as NOS in my parts drawers and amongst the
boxes I've inherited from others. Never really considered the
possibility that any of it had value. "There's gold in them there
drawers!!!!"

Perhaps more than you might think - and they don't even have to be
unused. Look at the fleabay prices for "mustard capacitors" and
"germanium transistor"





Re: OT: Old ICs for sale

Tom Gardner
 

On 11/06/18 18:50, Dennis Tillman W7PF wrote:
Hi Tom, and everyone who bids on Ebay,

There is some misunderstanding about prices on Ebay: Newbies and or sellers with stores frequently list their items with arbitrarily high prices. Sometimes they simply look at current listings and price accordingly.

BUT what really matters is what these items SOLD for. To find that out you have to look carefully through the completed listings for the auctions that were successfully concluded.
Indeed, but care isn't needed: just select "sold listings" :)

There are a couple of other useful tools for buyers:

  - to find out what an "or best offer" actually sold for, use http://www.watchcount.com/ and paste in the item's number (as found buried in the URL)

  - to find out what offers a seller has accepted/rejected, use https://www.goofbid.com/ebay_best_offers_tool.html# with the seller's name

That will tell you the true price the market thinks this is worth.

If there is an outlier in the completed auctions that sold for a truly outrageous price you have to look at the bidding that took place. It was probably between two newbies that didn't understand how Ebay works and they kept outbidding each other by a few dollars each time. If you are a seller you always hope your item will be bid up by newbies to absurd prices. It is lots of fun to watch one of these bidding wars take place and wonder where it will end.
Try watching the live online auctions!

Dennis Tillman W7PF

-----Original Message-----
From: Tom Gardner Sent: Monday, June 11, 2018 12:43 AM

On 11/06/18 05:19, G Hopper wrote:
I suppose that for $55 there probably is some value in that offering
even if some of the chips are dead. I do have to chuckle since I have
some of the same stuff as NOS in my parts drawers and amongst the
boxes I've inherited from others. Never really considered the
possibility that any of it had value. "There's gold in them there
drawers!!!!"

Perhaps more than you might think - and they don't even have to be
unused. Look at the fleabay prices for "mustard capacitors" and
"germanium transistor"