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Re: 5642 rectifier tubes in a Tek 535: Replace or swap for silicone?

 

Hi Mike,

That's terrific- certainly a lot cheaper than the diodes from Digikey. I hadn't seen that site before and it looks like they have some great stuff! I'll have a browse now and I'll let you know how I go.

Thanks again for your advice- I really appreciate it.

Kind regards,

Dom.
Re: DM502 with problems

 

Quick update to close the loop. I went through the components related to the NE555 timer and concluded that it was, indeed, a dead IC. I injected a 20.48 kHz signal at the output of the NE555 and the display came to life. I replaced the IC and its working great. Calibration was pretty much spot on as far as i can tell with my limited testing. Thanks again for all the feedback. Another TM504 lives along with the PS503A, FG502 and of course the DM502 that came with it. The fourth slot has a storage box that had an unused temperature probe & manual and a variety of test leads, banana jumpers and some odd push-in BNC jumpers with molded plastic ends that fit into a female BNC and will accept a male BNC on the back side of the plug. Looks great along side the TM503 . . .

Rich
7000 test/cal module(s) and backplane breakout board.

 

I have a 7904A, that I intend to keep in good working order.
However, I've not seen many cal fixtures on the market and reckon the
prices are only going to go in one direction for the near future. I am
planning to design one or more cal fixture(s) using modern components. I
figure I'll learn a lot more about the scope in the process, have some fun,
share the designs, and hopefully others can find the work useful.

Step 1 in this process is a simple passive breakout board for the backplane
connections, to allow me to experiment and prototype things. I checked the
archives and did not see an existing design, so I cooked one up. The
v1 boards are just back from fab and I have uploaded some photos here:
/g/TekScopes/album?id=266487 I am in the process of
mounting the board in a parted-out 7A26 module frame that I had on-hand,
will update more photos as I continue (assuming there is interest.)

This board brings out the high speed signals to BNCs and the low speed
signals to screw connectors. The low speed signals are grouped roughly by
function (power, readout, IEEE-488, misc.) Be aware that for this version,
I did not match the high speed signal path lengths, or worry too much about
impedance.

I'll probably create a project page somewhere with the eagle files, the
BOM, and progress as I work on cal/test fixtures, if anyone wants to follow
along. Look for an update when I get organized enough to do that.

--
Andy
Re: Paper Used in Older Tek Manuals

 

Greetings,

Just FYI, both of my Ibico punches are combination machines.

One has an electric driven punch the other is manual. Both have a section on the top of the unit used to install or remove the comb.

Enter a search for "Ibico comb binding machine" and you should get an assortment of images.

I like this style of binding documents.

Take care,

Ken

On 26Jul, 2021, at 6:22 PM, Michael W. Lynch via groups.io <mlynch003@...> wrote:

Get the comb binding punch and the installer as well. Two pieces are necessary.

--
Michael Lynch
Dardanelle, AR
Re: Paper Used in Older Tek Manuals

 

Get the comb binding punch and the installer as well. Two pieces are necessary.

--
Michael Lynch
Dardanelle, AR
Re: Paper Used in Older Tek Manuals

 

Get a Comb binding tool if you can get one cheap.

--
Michael Lynch
Dardanelle, AR
Re: Paper Used in Older Tek Manuals

 

re: multiple copies, yeah Dave, it can get pretty bad pretty quick! My wife has an easy solution. I can have as many manuals as I can fit in one double drawer file cabinet. :-)

For my part, sometimes I do have two copies - these days, usually a printed from electronic version in a three-ring binder. This is my "scratch and dent" version. I mark it up, leave it on the bench, get it dirty, etc. Then I have a "real" factory manual that I try to keep nice.

Jeff, talking about those comb binder installation tools, I think I saw a couple of those out at the local State Property Redistribution Warehouse a couple of weeks ago. I didn't pay too much attention, but now I'm starting to wonder if I should go grab them.

Those spiral or comb style or whatever they're supposed to be called are kind of snazzy.

Keith
Re: Paper Used in Older Tek Manuals

 

Why would one want multiple paper copies of a manual? I copy pages (mostly schematics) when I want to annotate them while troubleshooting, but I have eight file cabinet drawers of manuals. Having extra copies of them would be untenable.

The few non-original manuals that I have (mostly from Artek manuals) are bound with comb bindings. Three-ring binders take up too much space; many of the HP manuals that I have are huge (the manual set for the HP 8566B comes to mind).

DaveD

On Jul 26, 2021, at 18:06, Jeff Dutky <jeff.dutky@...> wrote:

?Also, a number of my Tek manuals, including the one that I just printed out from a PDF, were punched for both comb binding and three ring binding. Most of the manuals that I have with three-ring holes punched are BIG (e.g. the service manuals for the 475 and 2236). For the thinner manuals I can see where you might want to keep several of them in a big D-ring binder, but for the thick ones I don't see how that is practical. Does anyone know what the intent of this was?

-- Jeff Dutky
Re: Paper Used in Older Tek Manuals

 

Remove the comb and put it in a 3 ring binder? I've seen manuals from other manufacturers where they show a picture of what the manual will look like but when you get it it's actually in a 3 ring binder.

Vince.

On 07/26/2021 06:06 PM, Jeff Dutky wrote:
Also, a number of my Tek manuals, including the one that I just printed out from a PDF, were punched for both comb binding and three ring binding. Most of the manuals that I have with three-ring holes punched are BIG (e.g. the service manuals for the 475 and 2236). For the thinner manuals I can see where you might want to keep several of them in a big D-ring binder, but for the thick ones I don't see how that is practical. Does anyone know what the intent of this was?

-- Jeff Dutky



--
Michigan VHF Corporation -- nobucks dot net
K8ZW -

Re: Paper Used in Older Tek Manuals

 

Also, a number of my Tek manuals, including the one that I just printed out from a PDF, were punched for both comb binding and three ring binding. Most of the manuals that I have with three-ring holes punched are BIG (e.g. the service manuals for the 475 and 2236). For the thinner manuals I can see where you might want to keep several of them in a big D-ring binder, but for the thick ones I don't see how that is practical. Does anyone know what the intent of this was?

-- Jeff Dutky
Re: Paper Used in Older Tek Manuals

 

I have no argument with what you're trying. Go for it!
TDS540 Capacitor List

 

Hi Folks,

Has anyone compiled a list of the electrolytic caps for the TDS540? I¡¯d rather not pull mine apart until I have the parts in hand.

Thanks,
Stefan
Re: Couple of 576s available on allsurplus auction

 

Hi Paul,
I didn¡¯t bid, but I sure did consider going over to Tuscaloosa to get those three 575 at $10 each.
:-)

FWIW, I see yet another 576 up there now - this one is in Vegas. Ends tomorrow afternoon. Currently no bids and they want $100
Re: SG503 question

 

I have worked on several SG503;s and a common problem causing dropouts is failed solder joints on the range switch to he board that is right-angle to the main board. But re-doing these requires unsoldering that board from the main board.

--
Bob Haas
Re: 5642 rectifier tubes in a Tek 535: Replace or swap for silicone?

 

Dom,

I have used 2CL2H diodes to replace 5642s. The are higher rating than some others that can be used. I got mine off fleabay. If you replace some of the 5642s, the Si diodes would be in the cathode circuit as this has the highest current in the high voltage circuit. The Si diodes work fine and are very fast switching 12kV types.

Mark
Re: Couple of 576s available on allsurplus auction

 

Did anyone here get that? The total ending price (with buyers premium) turned
out to be $406.43, which was a really great deal.

On Thu, Jul 08, 2021 at 01:09:55PM -0700, Chris Wilkson via groups.io wrote:
The way I read it is a single lot...2 units for one money.
But it really isn't very clear.
Fabulous price (currently)!

One early unit - SN B071082
One late unit - SN B315353

--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows
Re: WTB: Case ring for 466

 

I've used (successfully) the tek 335 and 305 feet. Note Jeff has a direct site too, pricing may be bit better: search -
www.n0dy.com

Ben
Re: 5642 rectifier tubes in a Tek 535: Replace or swap for silicone?

 

Dominic:

How about the following as a possible source:

(10) diodes for under US$12.00. Claimed to be equivalent to Tek 152-0408-00.

I have no affiliation with the seller.

Mike D. N4MWP

On 7/26/21 7:10 AM, Dominic O'Kelly wrote:
Photos attached for reference:

/g/TekScopes/album?id=266461

From the looks of it- five new 5642 tubes will cost me $40 USD including postage, whereas five NTE-518 diodes will be almost exactly the same price.
Re: 5642 rectifier tubes in a Tek 535: Replace or swap for silicone?

 

Photos attached for reference:

/g/TekScopes/album?id=266461

From the looks of it- five new 5642 tubes will cost me $40 USD including postage, whereas five NTE-518 diodes will be almost exactly the same price.
5642 rectifier tubes in a Tek 535: Replace or swap for silicone?

 

Hi Everyone,

My name's Dom- long time listener first time caller. I've visited Groups.io a few times after searching for old Tek scope info- So I'm glad to finally be interaction with you all!

I have two old Tek scopes- a 535A and a 545B. The 545 is up and running, albeit with a few problems but the 535 is right at the start of the restoration process. It's not in the best condition- I saved it from the scrap heap after its previous owner passed away. I'd hate to see it destroyed.

But one question I'd like to run by the hive mind is about the 5642 rectifier tubes. They're all in pretty poor condition- some of them have actually corroded off their leads. So given I need to replace them anyway perhaps upgrading to a silicone diode could be wise?

I've seen other suggestions online that the NTE-517 of NTE-518 is a good substitute. Has anyone else had luck with this?

I'll attach some photos in my bio- you'll see the Sprague paper oil caps have leaked so they'll have to be replaced too- and the HV section cleaned.

Thanks in advance,

Dom.
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