Re: in-circuit capacitor testing (ESR tester) -- ideas appreciated.
I use an Extech LCR200 for in-circuit testing. It computes the overall
impedance at your specified frequency. Just make sure you COMPLETELY
discharge the capacitors using a 25K high wattage power resistor. It can
take several seconds to remove the residual charge from the capacitor's
deep recesses.
Gary
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On Wed, Jul 21, 2021 at 6:35 AM Ronan <bass.woofer@...> wrote: Hello again,
My main thread is " 2712 SA with display (and normalization) issues".
Due to the large number of electrolytic caps this SA has, I wonder if
anyone can recommend a (not too costly) in-circuit ESR capacitor tester I
could use to narrow down problem caps that otherwise show no obvious signs
of failure (i.e. leaking, exploded).
I've seen the tweezer-type LRC testers, and they might work for in-circuit
SMD capacitor testing, however, thought I'd run this by everyone first,
since I have no experience with such in-circuit cap testing/testers.
Creating a new Topic, since this is a generic question.
Thanks in advance,
Ronan
--
Gary Robert Bosworth
grbosworth@...
Tel: 310-317-2247
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Re: in-circuit capacitor testing (ESR tester) -- ideas appreciated.
Everything you ever wanted to know about ESR and various designs:
I built one of those designs and it was very helpful. There's also an ESR adapter for your dmm on the eevblog. That one is also on that site
There's a link on that page to the original discussion.
These things are so easy to build it's almost not worth buying something. And for testing, having 0.01 ohm resolution is worthless.
Paul
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On Wed, Jul 21, 2021 at 06:35:44AM -0700, Ronan wrote: Hello again,
My main thread is " 2712 SA with display (and normalization) issues".
Due to the large number of electrolytic caps this SA has, I wonder if anyone can recommend a (not too costly) in-circuit ESR capacitor tester I could use to narrow down problem caps that otherwise show no obvious signs of failure (i.e. leaking, exploded).
I've seen the tweezer-type LRC testers, and they might work for in-circuit SMD capacitor testing, however, thought I'd run this by everyone first, since I have no experience with such in-circuit cap testing/testers.
Creating a new Topic, since this is a generic question.
Thanks in advance,
Ronan
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@... | Unix/Linux - We don't do windows
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in-circuit capacitor testing (ESR tester) -- ideas appreciated.
Hello again,
My main thread is " 2712 SA with display (and normalization) issues".
Due to the large number of electrolytic caps this SA has, I wonder if anyone can recommend a (not too costly) in-circuit ESR capacitor tester I could use to narrow down problem caps that otherwise show no obvious signs of failure (i.e. leaking, exploded).
I've seen the tweezer-type LRC testers, and they might work for in-circuit SMD capacitor testing, however, thought I'd run this by everyone first, since I have no experience with such in-circuit cap testing/testers.
Creating a new Topic, since this is a generic question.
Thanks in advance,
Ronan
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Re: 2712 SA with display (and normalization) issues
#photo-notice
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Re: Replace/Repair TM 500 Module Side Panel Latch
Both my PS 503A modules have clip-in side panels. And as to the side panels being perforated or not, my assumption for which ones are perforated and which are not is it is heat-related, but this is not consistent either¡my parts DM 501A has perforated panels, my operational DM 501A does not¡need to look at serial numbers.
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Re: Replace/Repair TM 500 Module Side Panel Latch
I have a small collection of TM500 plug-ins, of which these have these latches:
PG506 1 latch missing
TG501
SG503 Both latches missing
FG503
PS503A
I agree with Dan on the part-numbers, which are also shown in some of the Service Manuals (my DC503A Manual shows both types of side-panel (referred to as "shield, electrical") with the earlier clip-in type ending at p/n B035909 and the newer latching type starting at p/n B035910. My DC503A has the earlier side-panels.
It is possibly worth noting that both these side-panels and the earlier ones which just clip into place come in two flavours - perforated and non-perforated. This is presumably because some plug-ins generate more heat than others and need extra ventilation (?).
Colin.
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Michael W. Lynch via groups.io Sent: 21 July 2021 02:52 To: [email protected]Subject: Re: [TekScopes] Replace/Repair TM 500 Module Side Panel Latch On Tue, Jul 20, 2021 at 04:59 PM, Jeff Dutky wrote:
Anybody know what that latched cover is for?
Jeff, PG506 has them on at least some examples. These are used only on plug-ins that include the rear support frame. I will need to look as I think I have a couple of others which have the same side covers and latch mechanisms. . -- Michael Lynch Dardanelle, AR
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Re: Recreating an old board for the 7854
I need to figure out how to make Kicad do a PCB edge connecter. You can use Python scripts to generate the Kicad footprints for the PCB edge connectors. I've done it for my TM500/5000 and 7000 series extender projects. You should be able to re-target these scripts. I can even help you do so if you want.
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Re: Replace/Repair TM 500 Module Side Panel Latch
The trick to gluing the two halves together, if that is necessary, is avoiding the adhesive binding against the side panel itself. This leaves little surface area to bond between the two halves. I¡¯ve got more pondering to do on that option. I have one broken one. The other one I figured out how to separate the two without breaking something. I used a pair of hemostats to pinch the locking ears on the external piece. With the hemostats I was able to pinch and gently push, ultimately popping the external half out of the internal latch piece. And, using care, was able to do so without damaging the ears and core of the external piece so much that I can¡¯t reassemble it. Is it marred? Yes, but it¡¯s minimal.
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Re: Replace/Repair TM 500 Module Side Panel Latch
On Tue, Jul 20, 2021 at 04:59 PM, Jeff Dutky wrote:
Anybody know what that latched cover is for?
Jeff, PG506 has them on at least some examples. These are used only on plug-ins that include the rear support frame. I will need to look as I think I have a couple of others which have the same side covers and latch mechanisms. . -- Michael Lynch Dardanelle, AR
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Re: Recreating an old board for the 7854
Which one is Q510? I see 2 Q500s but no Q510. Of course it could just be me.
Vince.
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On 07/20/2021 08:48 PM, Zentronics42@... wrote: I have uploaded the schematic that I have drawn up in Kicad in the files section. Given the new information for Q500 and Q510 I think I will need a different part in CR511. I need to figure out how to make Kicad do a PCB edge connecter. But here is the work so far. Since I am still in the schematic phases and have not started laying down foot prints I need to decide thru hole or SMD construction. The transistors will be SOT-23 so they are SMD.
Zen
-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of GeorgeP
Sent: Tuesday, July 20, 2021 6:05 PM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854
On Tue, Jul 20, 2021 at 01:13 PM, <Zentronics42@...> wrote:
When the design is checked and tested If there is any interest in
these let me know. Not sure how many out there want to tackle a full cal of a 7854.
I am interested. Thanks!
--
Michigan VHF Corporation -- nobucks dot net
K8ZW -
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Re: Recreating an old board for the 7854
I have uploaded the schematic that I have drawn up in Kicad in the files section. Given the new information for Q500 and Q510 I think I will need a different part in CR511. I need to figure out how to make Kicad do a PCB edge connecter. But here is the work so far. Since I am still in the schematic phases and have not started laying down foot prints I need to decide thru hole or SMD construction. The transistors will be SOT-23 so they are SMD.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of GeorgeP Sent: Tuesday, July 20, 2021 6:05 PM To: [email protected]Subject: Re: [TekScopes] Recreating an old board for the 7854 On Tue, Jul 20, 2021 at 01:13 PM, <Zentronics42@...> wrote:
When the design is checked and tested If there is any interest in
these let me know. Not sure how many out there want to tackle a full cal of a 7854.
I am interested. Thanks!
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File /Tektronix 7854 Test Card PCB files/7854 Test Card Preliminary Schematic.pdf uploaded
#file-notice
The following files have been uploaded to
the Files area of the [email protected] group.
By: Zentronics42@...
Description:
1st run at the schematic for the 7854 Test Card
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Re: Replace/Repair TM 500 Module Side Panel Latch
Hmmm... Silly me, at a glance I always thought these were just good old fashioned Dzus fasteners, but that shows how little I know about Tek's passion to custom build everything. :-)
Keith
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Re: Recreating an old board for the 7854
On Tue, Jul 20, 2021 at 02:13 PM, <Zentronics42@...> wrote When the design is checked and tested If there is any interest in these let me know. Not sure how many out there want to
tackle a full cal of a 7854.
Zen
Eric, I am certainly interested the boards as well. Thanks, Shaun M.
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Re: Replace/Repair TM 500 Module Side Panel Latch
By latched cover, do you meant just the blank cover?? I have two of them, used for improving airflow and keeping debris and fingers out of empty compartments.
-Dave
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On Tuesday, July 20, 2021, 02:59:54 PM PDT, Jeff Dutky <jeff.dutky@...> wrote:
Before we start trying to manufacture a replacement (which I think is a fine idea, especially in this new age of 3D printing) I'm wondering if there is a Tek part number for these? I have the cover, but not the thing it goes to (whatever thing that is). I don't expect to find a service manual for the TM500 toolbox, but the perforated cover must go to something other than the toolbox.
Anybody know what that latched cover is for?
I have been unsuccessful in separating the two halves of my damaged latch, but I've been trying to do so non-destructively, as I'd like to have them to take dimensions off of. It looks like the halves snap together, as I said, but more specifically there appear to be compressible, one-way flanges on the inner shaft that lock the halves together. There are also two vertical flanges (very thin) that engage one half to the other, and it appears that those have sheared off in my failed latch, so that the two halves now rotate independently.
If I can get a good set of measurements on the two halves I could try to draw up and print a replacement. I'd think hat you could design a sturdier version of this part that wouldn't tend to fail in this way (e.g. rather than a circular shaft with flimsy vertical flanges, why not make the shaft square, or rectangular? It would be much less likely to shear off if there were more material).
-- Jeff Dutky
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Re: Replace/Repair TM 500 Module Side Panel Latch
On Tue, Jul 20, 2021 at 05:59 PM, Jeff Dutky wrote: Before we start trying to manufacture a replacement (which I think is a fine
idea, especially in this new age of 3D printing) I'm wondering if there is a
Tek part number for these? The latch part numbers should be 105-0932-00 and 214-3364-00. They are described in great detail in the Mechanical Common Design Parts Catalog from November 1988. dan
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Re: Recreating an old board for the 7854
On Tue, Jul 20, 2021 at 01:13 PM, <Zentronics42@...> wrote:
When the design is checked and tested If there is any interest in these let me
know. Not sure how many out there want to tackle a full cal of a 7854.
I am interested. Thanks!
|
Re: Replace/Repair TM 500 Module Side Panel Latch
Before we start trying to manufacture a replacement (which I think is a fine idea, especially in this new age of 3D printing) I'm wondering if there is a Tek part number for these? I have the cover, but not the thing it goes to (whatever thing that is). I don't expect to find a service manual for the TM500 toolbox, but the perforated cover must go to something other than the toolbox.
Anybody know what that latched cover is for?
I have been unsuccessful in separating the two halves of my damaged latch, but I've been trying to do so non-destructively, as I'd like to have them to take dimensions off of. It looks like the halves snap together, as I said, but more specifically there appear to be compressible, one-way flanges on the inner shaft that lock the halves together. There are also two vertical flanges (very thin) that engage one half to the other, and it appears that those have sheared off in my failed latch, so that the two halves now rotate independently.
If I can get a good set of measurements on the two halves I could try to draw up and print a replacement. I'd think hat you could design a sturdier version of this part that wouldn't tend to fail in this way (e.g. rather than a circular shaft with flimsy vertical flanges, why not make the shaft square, or rectangular? It would be much less likely to shear off if there were more material).
-- Jeff Dutky
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Re: Working on the HV Section of a 533A
Dave,
I suspect that all three of the tips I have are worn out. I discovered two tips, still in their bags, in a plastic "parts deresser" (plastic drawers for electronic parts, cheap a Radio Shack, back in the day). One is a long conical point (my favorite style) 700¡ãF tip, and the other is a 600¡ãF screwdriver tip (though it looks conical to me). I also ordered a half dozen new Weller tips on Amazon of various styles and temperatures, including a pretty broad "sloped" tip (but it's 800¡ãF, so maybe not appropriate for most work). I'll be sure to order a couple more 600¡ãF tips, if I can find them in broader styles.
The TC201 is very nice to use. My father had another, much cheaper soldering iron (or "pencil") that plugged directly into the wall (the two prong power cord came straight out the back of the handle). The TC202 seemed like ridiculous extravagance back in 1985. The fact that you could just unscrew the outer sleeve and swap the tips was astonishing. I'm still sorry that I didn't know how to take care of the tips properly, or they would probably still be in good condition.
I've watched a few videos about proper care of your soldering iron and tips, and I'm going to give a go at correctly cleaning and tinning the tips I already have, but I'll be more focused on keeping the new ones in better condition.
-- Jeff Dutky
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Re: Recreating an old board for the 7854
Any chance there is high rez photos of a production analog test board? I have only seen the scan in the manual and I have some questions about layout and locations. Like of the BNC connector. I can get measurements off the Digital board cause they share dimensions. But there is a pin connector and a BNC connector I have some questions about where they go and why they are there.
Zen
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Clark Foley Sent: Tuesday, July 20, 2021 4:23 PM To: [email protected]Subject: Re: [TekScopes] Recreating an old board for the 7854 Time for the Cone of Silence before we get the OT warning! Now back to the 7854. I use the board to run my analog backup 7854 parts. It has no Max, I mean smarts, in it. I kludged in 7k readout board and now I have a fully functional 7804. Some of the boards are early prototype boards and some from different production runs. Think of Johnny Cash¡¯s ¡°One Piece At A Time.¡± No fins on it though!
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Gary Robert Bosworth
Michael W. Lynch
Shaun M
GeorgeP