开云体育

I agree with Rick K8EZB that Goo Gone, the citrus-based product, is a good choice for removing many labels. I let the label soak for 30 minutes (Goo Gone is aqueous so it evaporates slowly) and then work to remove the label. If there is substantial paper label remaining, an "orange stick" or even a fingernail can remove the paper, followed by more soaking in Goo Gone. Finally, a soft cotton shop or kitchen towel can remove the remaining adhesive residue. Using a typical kitchen paper towel too vigorously can scuff the paint. I've even used cotton balls in critical areas.

I also use Simple Green Extreme (well diluted) on Tek painted cabinetry. I put a splash of SGE in a tub of warm water and let the case soak for 30 minutes per side, then scrub with a soft brush. I have a kitchen Reverse Osmosis water system so I always do a final rinse in RO water.

Now, I've heard some folks complain about Simple Green; I've never tried that product. You would think Simple Green Extreme would be more of a problem than Simple Green, but I've never had any problem with SGE on painted surfaces when diluted. The supplied SGE is quite concentrated so it must be diluted. SGE is a little difficult to find but I got my last gallon jug on Amazon.

Incidentally, I often use RO water to wash electronics without issue. Water does not harm most electronics but residual minerals from tap water certainly does! Spill coffee on your computer keyboard? Just rinse thoroughly with RO (or, distilled) water. Anyway, anything I wash with a detergent (e.g. SGE) I final-rinse with RO water.

I do have Goof Off, a solvent-based product, but don't dare use it on painted surfaces. But, if you have a label on a stainless steel surface, Goof Off is quick and safe to use. I finish with Goo Gone and RO water rinse.

I've found instruments with solid brass ID tags bonded with a really hard adhesive. Those are tough to get off...

Isopropyl alcohol is ineffective on most adhesives. Methanol is a much better solvent but will attack some paint finishes and must be used with good ventilation. Finding methanol is getting harder and harder; it seems to have disappeared in California big box stores but is still available in California as a race fuel for motorcycles and cars.

I work on many microscopes with aged grease that is tough to get off. Soaking in xylene works well but again that solvent must be used with good ventilation and it is no longer available in California; it is available at Home Depot in every other state. Not for use on any paint!

For microscope mechanical subassemblies with dried grease, I use a succession of dirty-to-clean xylene in large-mouth screw jars. I use the jars with Teflon lid liners available from McMaster-Carr.

I do use isopropyl alcohol for flux removal but I get the anhydrous alcohol available from some drug stores and from industrial hardware stores.

There is no single-best approach and you must apply caution and wisdom to prevent damage.

Larry



On 6/11/2018 7:10 PM, Dennis Tillman W7PF wrote:

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.

...

--
Best wishes,

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

I fooled around with this a little more today. The CRT HV stuff seems to be about right, and I bypassed the video (blanking) amplifier, with no change in intensity. Instead of getting buried in details, I decided to take a drastic measure and just jumpered the G1-K on the CRT - this would allow maximum (or excessive) beam current and the brightest trace possible. Still no effect, so it looks like this one is a goner, but will be an ideal candidate for CRT rejuvenation experiments. Next time I'm inclined to fool around with the rejuvenator, I'll give it a shot and see what happens, but for now I'll set it aside. I probably have a socket that will fit, and just need to get the heater voltage spec for this tube, and some time.

Ed

Have you tried Goo Gone? Also, WD-40?

Barry - N4BUQ

Once upon a time? NAPA had a spray can of sticker removal that would lift out the solvent in the glue so that all that was left was the rubber solid and it rubbed right off afterward. It was under their own brand name, don't know if it is still available now haven't looked recently. It was not harmful to the old lacquer style paints from the 40's - 50's.
Might be worth a try if it is still there.

Jim Olson (sorry no call sign.)

Welcome!
My first scope was a 502, and I really pushed the bandwidth, using it to look at waveforms on the Commodore PET and CBM computers.? It was actually the reason I joined the group too.
Unfortunately, I never did repair mine (I think the problem was the rectifier tubes), because too many other projects came up.
-Dave

From: "jrodriguezcsb@..." <jrodriguezcsb@...>
To: [email protected]
Sent: Monday, June 11, 2018 7:12 PM
Subject: [TekScopes] Help with a TEK 502 scope

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.

Try Goo Gone, a citrus based product (not to be confused with Goof Off, a
paint remover). I have used this to remove cal sticker adhesive from
several Tek and Agilent instruments. Be gentle!

Rick
K8EZB

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

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 : )

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.

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.

The manual has been uploaded to Didier's site () and to the TekWiki site ().

Enjoy!!
Dave M

NOTHING TO READ ABOVE ????

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

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

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?

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 <hrgerson@...>
To: [email protected]
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

Perhaps of use to someone ?

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

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.

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@...>
To: "[email protected]" <[email protected]>
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@...>
To: [email protected]
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

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

Phil, N6OMM

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 <john@...>
Lots of things can go in flat rate USPS envelopes stuffed to resemble a football.??-=-=-=-=-=-=-=-=-=-=-=-