Re: Upgraded, stub tuned, Tektronix SG-504 leveling head back online for a last run
Thanks to all and sundry in the group for their support.
All the ordered leveling heads have been shipped out, including the item ordered this morning.
I believe there are enough parts in my stock for another 3 or 4 units should demand recur.
Stub tuning to compensate for each build is a custom activity, but it is the only way to reliably exceed Tektronix head specs by a significant and meaningful margin and breathe a bit of extra life into the excellent SG-504 plug-in.
Ancel.
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I do not see any regulatory markings on it and you have 120-240V with high current on flying leads. Be careful. Just sayin. I just narrowly avoided an RV fire from a 120V to chassis short due to poor wiring practices of the original installer. I'm just a little cautious right now! Regards Mark On Wed, Jun 20, 2018 at 12:45 PM, Ed Breya via Groups.Io < edbreya@...> wrote: Michael A. Terrell wrote:
"
Durable-AC-80-260V-LCD-Digital-20A-Volt-Watt-Power-Meter-Ammeter-Voltmeter
US $7.99 plus shipping."
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Michael A. Terrell wrote:
"
Durable-AC-80-260V-LCD-Digital-20A-Volt-Watt-Power-Meter-Ammeter-Voltmeter
US $7.99 plus shipping."
That's pretty slick for ten bucks, for common AC monitoring.
Unfortunately, the specs don't say if any measurements are true RMS or not. For the voltage, average reading is sort of OK since the line will be "mostly" sinusoidal, but current may be some nasty waveforms, and so will the power that goes with it, so true RMS is best for accuracy. There are ICs that can make the V and I measurements with ADCs, and properly calculate these and other AC parameters. If they've used such a one, it could be a very cool little monitor - especially for the price.
If anyone is planning to get some to try out, please let us know what you find, and if they are capable of "true" measurements - it's easy to figure out with a few experiments. If these are indeed capable, then I'd be interested in getting some too.
Ed
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I bought one because of the size. It was small enough to mount with an isolation transformer and Variac. It wasn't meant as an insult, just a way to free up other equipment and to use less bench space. :)
Michael A. Terrell
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-----Original Message----- From: M Yachad <yachadm@...>
Just goes to prove that I'm a caveman!
Nice toy that - might even consider it!
I like that it can handle 20A.
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Menahem wrote:?>I personally do not use tantalums. It scares the crap out of me taht when they fail, they short. And to have to clean up that mess - all the failed components around that tant cap - just makes it very unattractive.
I agree.? But when they work, they last "forever". ?
Menahem wrote:>Long ago, I installed (once only) Panasonic FC SMD's.
Since then, Panasonic FC or Nichicon HE, regular leaded caps, with their leads bent small and cut, standing upright to fit perfectly on the SMD solder pads.
I have Panasonic FC SMD installed now.? But I know they will eventually leak.? But one advantage I have this time is they are not wave soldered.? I carefully hand solder the SMD so their seals don't experience the heat of wave solder or reflow.? I have sealed the board repairs with CW2500 epoxy overcoat.? Hopefully that will help.? I don't think the repair pads will do well with a leaded cap hanging on it.
Thanks for the information.? It seems we agree on the outcomes here.
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On ?Wednesday?, ?June? ?20?, ?2018? ?07?:?26?:?24? ?AM? ?CDT, M Yachad <yachadm@...> wrote:
Ron
"Finally, what capacitors do you advise to use on the 24x5B A5 board?? I am now repairing my second one and need to make choices for at least the electrolytics.? Both boards I have are missing pads from missing electrolyte leakage.? I clean the boards and replace the pads.? But if I replace the capacitors with electrolytic caps it is certain they will fail one day and it is certain they will further damage the board and my replacement pads are not as robust as the originals.? I see one seller of rebuilt A5 boards uses tantalum electrolytics.? But tantalums are notorious for failure unless significantly de-rated for voltage.? For now I have used electrolytics but have started a plan to change them out for tantalums, derated 2:1 or more. "
I personally do not use tantalums. It scares the crap out of me taht when they fail, they short. And to have to clean up that mess - all the failed components around that tant cap - just makes it very unattractive.
Tants came into this world in the late 1960's with one advantage only - small size. As long as there is the real-estate for a regular Elco, then that's what I install.
This is my opinion only, YMMV.
Specifically on the later A5 SMD's?
Long ago, I installed (once only) Panasonic FC SMD's.
Since then, Panasonic FC or Nichicon HE, regular leaded caps, with their leads bent small and cut, standing upright to fit perfectly on the SMD solder pads.
Works great, and I much prefer the reliability of leaded caps over the SMD caps.
Menahem
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Re: Tek push-button lettering using pressing iron transfer of laser printed text on non-sticking paper
Hello group
For 40 years or so I have been lettering my projects with india ink and protecting it with "clear nail polish" the best of these by far is HARD AS NAILS be sure to get clear not tinted. Part of the charm is the convenience since it includes a brush - just reach for the bottle at the back of the bench. One cravat - it is a good solvent and can only be used on water based printing, like the india ink pen from the art store. If you use it on a Sharpie there are smudging problems unless you are very fast. In more recent years I have largely switched to using labels made in a MS Word table. Word allows the table cell dimensions to be set precisely so its easy to cut the labels to the desired dimensions. For a terminal strip you adjust the pitch of the legends to match the terminal pitch then one long label does the whole strip. If using paper for the label base I glue it on with an Elmers glue stick and coat the label with the hard as nails. While at the art store look at the paint pens, the paint is acrylic and also works well with the hard as nails, comes in numerous colors that are opaque. As in white lettering for a black knob.
If you really want a first class protectant go with a UV-cured-resin "pen" sold under the name LAZER BOND . Tough and quick. Shop it, the price varies widely.
Eric WB6KCN
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Just goes to prove that I'm a caveman!
Nice toy that - might even consider it!
I like that it can handle 20A.
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Durable-AC-80-260V-LCD-Digital-20A-Volt-Watt-Power-Meter-Ammeter-Voltmeter
US $7.99 plus shipping. Mount it in a box with a switch for 1X/10X, and add an outlet.
It is simpler, cheaper and it does more. If you put ten turns through the current transformer, it will have 10X the sensitivity but the power readout will also be 10X higher.
Michael A. Terrell
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-----Original Message----- From: M Yachad <yachadm@...>
Sent: Jun 20, 2018 9:29 AM
To: [email protected]
Subject: Re: [TekScopes] Tek 465 no display
I built this easy AC Volt Ammeter setup in less than an hour.
This is my design - all praise and criticism goes right to the inventor - here!
I wonder now how I ever got on without it.
/g/TekScopes/album?id=60374
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George,
Take a look at the header of the message, where you should find Bert's email address - just like a normal email, really.
Good Luck,
Colin.
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of georgeK KB1HFT Sent: 20 June 2018 17:01 To: [email protected]Subject: Re: [TekScopes] CRT in Tek 2235 Tom & Bert: Thanks for the info! Yes, the 2235 is a fine scope. I believe I brought one with me ( i., e.< carried ) one service calls in the 1970's. Heavy, but essential. Tom: I will investigate Sphere and -10 tubes. Bert: How do I contact you "off list" <caution: newbie alert!!> -georgeK KB1HFT
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Tom & Bert:
Thanks for the info!
Yes, the 2235 is a fine scope. I believe I brought one with me ( i., e.< carried ) one service calls in the 1970's. Heavy, but essential.
Tom: I will investigate Sphere and -10 tubes.
Bert: How do I contact you "off list" <caution: newbie alert!!>
-georgeK KB1HFT
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Thank you for this list. And on a broader sense, for the education. This has been quite informative for me as a newcomer to this part of the electronics field. The comments and conversation have been a real eye-opener for me. I appreciate all those who have contributed to this discussion and to the site in general.
--
Michael Lynch
Dardanelle, AR
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Further to this, I note the Groups.io area for this forum includes a Wiki feature. Currently, it¡¯s a link to TekWiki, but could presumably be used to host content intended to be editable by anyone on this forum.
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On 20 Jun 2018, at 12:05, Dave Voorhis <voorhis@...> wrote:
On 20 Jun 2018, at 11:26, M Yachad <yachadm@...> wrote:
OK, I had a look at Google sheets.
Looks doable initially, but HOW would I upload it and make it accessible for the group, on the Group's Google account, if the group even has a Google account? When I¡¯ve been involved in similar efforts in the past, others who wish to edit the document are given access by the owner. Access to an entire group would be effectively public access, which is perhaps a bad idea. I doubt anyone would damage it maliciously, but the opportunity for accidental blunders would be very high.
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Yesterday I made the comments at the bottom about the 2235 vs the 2235A CRT differences.
The CRT's are both 154-0861-xx but one has a longer HV lead that the other.
The 2235 uses the 154-0861-00? (several other common 22xx's used this same -00 CRT)
The 2235A uses the 154-0861-10? (several other late production 22xx's used this same -10 CRT)
I said the -10 CRT from the 2235A had the shorter HV lead, and that was absolutely WRONG.
This morning I took the covers off of a 2235 and a 2235A and measured the HV lead lengths.
The -10 CRT in the 2235A has about a 25mm longer HV lead than the -00 CRT in the 2235.
So the 2235A CRT would fit in the 2235 with no modification, but you would need to lengthen the HV lead to use the 2235 CRT in the 2235A.
I hope this isn't too confusing, and I apologize for giving you bad information.
Old age and ignorance are my only excuses.
tom jobe...
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On 6/19/2018 6:05 PM, tom jobe wrote: Hi George,
That CRT is not all that rare as it came in many models of the 22xx series.
A few common models that also used it are the 2213A, 2215A as well as your 2235 and the 2236.
You can download free manuals of lower quality for many of the 22xx scopes, to see what part number they used.
The CRT uses a component number such as V9870 and may appear with the A6 parts in the listings, or at the end of the electrical parts listings.
As I remember... the CRT for the 2235A and the 2236A is part number 154-0861-10, which seems close enough, but the HV lead to the CRT is enough shorter that it will not work without an HV extender of some sort. They re-arranged the HV multiplier setup on the mainboard of the 2235A and the 2236A to use a shorter HV lead.
You want a -00 CRT for your 2235.
Other scopes that seem like they should use the same CRT part number are the plain 2213 and 2215, but they are both much different.
There are lots of "parts only" scopes for sale on eBay and elsewhere, and you can often buy one of them for not much money, especially if it is located close enough to you to avoid the shipping charges.
I think Sphere in Canada sells that CRT for about $85 plus shipping when they have them in stock, to give you some idea of it's fair worth in US dollars.
The 2235 is a fine scope, and the easiest to work on of all the Tektronix gear I have ever encountered.
It and its peers (from 2213A to 2236) were made in such large numbers that there is a substantial body of knowledge about it, what it's common old age ailments are, etc, etc.
tom jobe...
On 6/19/2018 9:27 AM, georgeK KB1HFT wrote:
I understand that the Tek2235 wants a 154-0861-00 CRT, which seems to be made of Unobtanium.
Are there any known substitutions?
Are there any _available_ known Substitutions?
Thanks in advance!
73
-georgeK KB1HFT
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I built this easy AC Volt Ammeter setup in less than an hour. This is my design - all praise and criticism goes right to the inventor - here! I wonder now how I ever got on without it. /g/TekScopes/album?id=60374Menahem
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
Ron
"Finally, what capacitors do you advise to use on the 24x5B A5 board? I am now repairing my second one and need to make choices for at least the electrolytics. Both boards I have are missing pads from missing electrolyte leakage. I clean the boards and replace the pads. But if I replace the capacitors with electrolytic caps it is certain they will fail one day and it is certain they will further damage the board and my replacement pads are not as robust as the originals. I see one seller of rebuilt A5 boards uses tantalum electrolytics. But tantalums are notorious for failure unless significantly de-rated for voltage. For now I have used electrolytics but have started a plan to change them out for tantalums, derated 2:1 or more. "
I personally do not use tantalums. It scares the crap out of me taht when they fail, they short. And to have to clean up that mess - all the failed components around that tant cap - just makes it very unattractive.
Tants came into this world in the late 1960's with one advantage only - small size. As long as there is the real-estate for a regular Elco, then that's what I install.
This is my opinion only, YMMV.
Specifically on the later A5 SMD's?
Long ago, I installed (once only) Panasonic FC SMD's.
Since then, Panasonic FC or Nichicon HE, regular leaded caps, with their leads bent small and cut, standing upright to fit perfectly on the SMD solder pads.
Works great, and I much prefer the reliability of leaded caps over the SMD caps.
Menahem
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On 6/19/2018 12:27 PM, georgeK KB1HFT wrote: I understand that the Tek2235 wants a 154-0861-00 CRT, which seems to be made of Unobtanium.
Are there any known substitutions?
Are there any _available_ known Substitutions?
Thanks in advance!
73
-georgeK KB1HFT If you want to buy one of these, contact me off list. Thanks, Bert
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
On 20 Jun 2018, at 11:26, M Yachad <yachadm@...> wrote: OK, I had a look at Google sheets.
Looks doable initially, but HOW would I upload it and make it accessible for the group, on the Group's Google account, if the group even has a Google account? When I¡¯ve been involved in similar efforts in the past, others who wish to edit the document are given access by the owner. Access to an entire group would be effectively public access, which is perhaps a bad idea. I doubt anyone would damage it maliciously, but the opportunity for accidental blunders would be very high.
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Re: FS: Tektronix scopes on craigslist; North of Boston, MA
Thanks for the kind words, hope that 7844 serves you well.
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Re: Up to date capacitor list for Tek 2465A and 2465B scopes (2018)
OK, I had a look at Google sheets.
Looks doable initially, but HOW would I upload it and make it accessible for the group, on the Group's Google account, if the group even has a Google account?
Menahem
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Ancel
Michael A. Terrell
Eric Schumacher
Mlynch001
Shannon Hill