Date   

Re: Tektronix DM5010 NiCa 2.4V battery replacement

musicamex
 

Half a century after men walked on the moon, can anyone please explain why
batteries still leak? Or why engineers capable of designing incredible
electronics can't at least protect the circuits from leak caused damage?
I'm sure that I'm not the only one who has lost often irreplaceable
electronics to this pitfall.

Russ

On Monday, July 23, 2018, Kevin Oconnor <@KO3Y> wrote:

You can certainly trickle charge some NiMH cells depending on the mfgr.
I’ve used Panasonic cells that have a trickle charge spec. The trick is
that the trickle charge level can’t generate more evolved oxygen than can
be absorbed at operating temps. That is the upper bound on trickle
charging.
There is also a lower bound on trickle charging that is often overlooked.
You have about 15-20 hrs max to recharge to full capacity. The reasoning by
mfgrs is vague but true and likely related to temp rise and gas evolution.
If you trickle charge at a rate less than that which will fully recharge in
15-20 hrs you will never fully restore full capacity.

Kjo

Sent from kjo iPhone



--
Good judgement comes from experience; experience comes from bad judgement.

99 times out of 10 a blown fuse is not due to a bad fuse.....


Re: Tektronix DM5010 NiCa 2.4V battery replacement

Kevin Oconnor
 

You can certainly trickle charge some NiMH cells depending on the mfgr. I’ve used Panasonic cells that have a trickle charge spec. The trick is that the trickle charge level can’t generate more evolved oxygen than can be absorbed at operating temps. That is the upper bound on trickle charging.
There is also a lower bound on trickle charging that is often overlooked. You have about 15-20 hrs max to recharge to full capacity. The reasoning by mfgrs is vague but true and likely related to temp rise and gas evolution. If you trickle charge at a rate less than that which will fully recharge in 15-20 hrs you will never fully restore full capacity.

Kjo

Sent from kjo iPhone


465B - Power Switch Mounting Nut Question

n4buq
 

A few months ago, I removed the trigger board from my 465B to work on the power supply caps. I started reassembling it and was left with a small nylon(?) block with a hex nut holder and a small slot in it. See the album below for pictures of it.

https://groups.io/g/TekScopes/album?id=64907

If I'm not mistaken, I think this is used behind the nut that holds the power switch in place and I used it that way (last picture); however, I'm wondering if I have it turned 180-degrees and the small slot is supposed to align with the main board.

Is that where that part goes and, if so, is it supposed to align with the other PC board? I've found one picture on the web that shows it and I think that's correct but would like to know whether I have that right.

Thanks,
Barry - N4BUQ


Re: 466-464 stray wire

Jim Olson <v_12eng@...>
 

Hello Fabio,
I think it had more to do with the sucker than me as it is quite hot so the solder melts quickly so it sucks up easy and out of the hole around the pin too. On wiggling the cap while heating the large pin I would just wiggle around lightly and when the solder melted it would move easy and so I would know it was loose melted.
Have inspected all the pads and holes with my head band magnifier and all looks good will verify with a dmm need to get a new battery as it is dead when I went to use it.
The 464 only uses the one cap at 1713 where as the 466 uses two my 464 only has one also.
On the three inside caps from the edge 1751. 1761, 1723 all the three holes in a row have the outer pads all connected to the ground trace so no need to jumper wire to the outer stand off pad as there is no trace on them and the same on 1721. On 1722 the single outer pad is not used so no wire there and 1781 the large hole pad not used either so no wire either 1722 is the one needing a wire as it has to have the single outer pad the - connection to the large hole on the inner row as it is the only ground pin used on that cap so small wire in BIG hole is prob to fill up maybe.

Jim


Re: 466-464 stray wire

Fabio Trevisan
 

Hello Jim,
I`m glad I was helpful.
On your comments about taking out the big capacitors, I can't be more glad that you didn't have problems. you're either very lucky, or very, very good with the solder sucker (or both).
I had to do the same on mine, I consider myself very good at desoldering using a solder sucker and always did this kind of job on double-sided, through-hole plated boards without hassle... and I had a real bad time taking mine out.
I lifted at least 3 or four pads from the capacitor side, and stripped out an equal number of through-hole vias.
It was a real pain to put it back together, without having to make ugly wire jumpers. (I used tiny bits of component leads and wires, to make back the connections between both sides, using the available space around the capacitor pins, sometimes making the pins a bit thinner, to make room for the interconnecting wires inside the holes.
Nevertheless, since you mentioned that you had to wiggle them a little bit for them to come out, I recommend you make a careful inspection of all the through-hole vias and make sure they're in good shape.
The adhesive that sticks the copper to the board on those ancient boards are not top notch compared to modern boards and they won't stand a second desoldering session so, you don't want to be forced to take them out once again, just because you overlooked some through-hole via.

Regarding your question about C1713 (couldn't find a C1712), when I got my 464 on 2016, this one was already replaced by an aluminum electro (of 25V).
This fact gives room for assumption that the original Tantalum of 25V failed in that position, and I wouldn't hesitate in shuffling a 35V tantalum, or even a regular aluminum electrolytic there.
However, in face of the majority of other Tant caps that are infamous for failing in those scopes (of which Tek sometimes would use a 15V cap on a 15V rail), this one spec'd at 25V is not so badly spec'd after all.
This winding of the transformer seems to be something about 10Vac, and it puts just about 14V (rectified) across this capacitor so, I think that even 25V there will do fine but, if you can fit a 35V capacitor there, it's the best case scenario.
Ah... in time... if what you're worried about this, is that it's a 25V cap on a +140V supply (actually +154 unreg)... no fears... it's hooked to the +140V supply at its negative side so, it only "sees" the difference (which is about 14V).

Rgrds,

Fabio

On Mon, Jul 23, 2018 at 05:42 PM, Jim Olson wrote:


Thanks Fabio for the reply. I opened my PDF copy of the 464 manual and found
the +15 volt end of the wire on the TRIG-VIEW switch but didn't know where it
went from there. Did some careful perusing of the TRIG-GENERATOR SWEEP BOARD
and found it at the bottom as you descibed it so then after I got my early 466
manual searched it out and found it also.
Appreciate the description of the circuit and also the chip diffs

i have started to put together the list of capacitors I am going to need and
have pulled the 6 caps from the interface board for the 466 I did not have any
real problem getting them off was a bit hesitant at first because of the
horror stories on here from folks doing that. Some time back I picked up a
real nice desoldering tool from Radio Shack it is a bulb sucker type with the
bulb attached above the handle and to the tip with a tube so you can put the
tip on the connection to be unsoldered and when soft just release the bulb
cleans off and out all the solder.
Once I got the first one out it was easy to see how they were attached just
put the tip hole down over the small pins first sucked out the solder so they
were loose the worked on the big one wiggling the cap while heating took two
three time to get it loose big hole filled up with solder on that one.

Have a question on two of the tant caps used in the power supply for one
section of the output they are two 47uf 25v caps # 1712 & 1713 they are in a
half wave rectified section and across the output for the +140v supply it
seems that 25v is a bit low here? Any comments here?

Jim


Re: OT: HP 70843B Error Performance Analyzer, 12 GHz BERT info needed

Ed Breya
 

Here is a list of the GaAs logic ICs used in the mux and demux modules. There are 12 pieces in each. I have found data sheets for a few, as shown, and a little descriptive stuff, and made some guesses based on the circuit topology. They were all made by NTT in the 1990s. If anyone knows of other info to fill in the blanks, it would be great.

TX 8:1 MUX
NL4515, 4pcs, no data, probably 2:1 mux, few GHz
NL4520-2, 1pc, have data - 3 GHz 1:2 clock distribution
NL4508, 1 pc, no data, probably a FF, few GHz
NLG4115, 3pcs, have data, 2:1 mux, 10 GHz
NLG4108, 2 pcs, no data, apparently 14.5 GHz TFF, used as clock divider
NLG4120, 1 pc, have data, 10 GHz 1:2 clock dist

RX 1:4 DEMUX
NL4506, 4 pcs, no data, probably few GHz 1:2 demux
NL4508, 1 pc, same as in MUX
NL4519, 1 pc, have data, 8 GHz 2-inp NAND, used as buffer
NLG4108, 1 pc, same as in MUX
NLG4120, 3 pcs, same as in MUX
NLG4104, 2 pcs, no data, probably 10 GHz 1:2 demux

It appears the NLG series are for full-speed sections around 10 GHz, while the NL series are slower, in the few GHz range. The HP70843B is spec'd to 12 Gbps, but probably at lesser performance beyond 10, or at high temperatures.

Ed


Re: 7603 specifically and general refurbishment procedures of older oscilloscopes

Albert Otten
 

Hi John,

There are a few things you could do before opening the cabinet.
It's possible that the scope is working normally but showing no trace because of a fault in the (un)blanking circuitry. You might check the signals at the rear panel BNC output connectors (Vert Sig Out, Gate Out, Sawtooth Out) to see if there is activity inside.
An (un)blanking fault could be present in the path from 7B plugin to/through the main interface board. I think, but I have no 7603 to test this myself, that the CRT will be unblanked anyway when you try the 7603 in XY mode using two 7A plugins. (Try this unfocused to avoid phosphor damage.) The dot position should listen to position controls.

Albert

On Mon, Jul 23, 2018 at 05:57 PM, <johnasolecki@...> wrote:


Hello everyone,

The '03 seems to work when the 7L12 is installed
but I can't get any kind of trace (except for readouts) when I use any of my
7000 series plug ins. I can't say I've tried every permutation but I've tried
installing a 7A19, a 7A22, 7A26 in conjunction with a 7B92, 7B92A, 7B80 and a
7B85 with the "A" plug ins in the center & left slot and the "B" in the right
with no joy.

Because of this problem I'll be opening up the 7603; if anyone has any
specific suggestions on where to look I'd be grateful but otherwise are there
any common procedures for the overhaul of an older scope?


Re: 466-464 stray wire

Jim Olson <v_12eng@...>
 

Thanks Fabio for the reply. I opened my PDF copy of the 464 manual and found the +15 volt end of the wire on the TRIG-VIEW switch but didn't know where it went from there. Did some careful perusing of the TRIG-GENERATOR SWEEP BOARD and found it at the bottom as you descibed it so then after I got my early 466 manual searched it out and found it also.
Appreciate the description of the circuit and also the chip diffs

i have started to put together the list of capacitors I am going to need and have pulled the 6 caps from the interface board for the 466 I did not have any real problem getting them off was a bit hesitant at first because of the horror stories on here from folks doing that. Some time back I picked up a real nice desoldering tool from Radio Shack it is a bulb sucker type with the bulb attached above the handle and to the tip with a tube so you can put the tip on the connection to be unsoldered and when soft just release the bulb cleans off and out all the solder.
Once I got the first one out it was easy to see how they were attached just put the tip hole down over the small pins first sucked out the solder so they were loose the worked on the big one wiggling the cap while heating took two three time to get it loose big hole filled up with solder on that one.

Have a question on two of the tant caps used in the power supply for one section of the output they are two 47uf 25v caps # 1712 & 1713 they are in a half wave rectified section and across the output for the +140v supply it seems that 25v is a bit low here? Any comments here?

Jim


Re: Homemade tunnel diodes

Bruce Griffiths
 

For the purposes of harmonic generation NLTLs have much lower PN than SRDs.
Bruce

On 24 July 2018 at 05:37 thespin@... wrote:


Modern mixer diodes are great but I have yet to find a good replacement for step recovery diodes.



Re: 466-464 stray wire

Fabio Trevisan
 

Hello Jim,

I used to owe a 464 that I refurbished completely, it had a DM44. I don't possess it anymore as I gave it as a gift to a friend...
I disassembled the Vertical Pre-Amp board and the Triggering board quite a few times and remember quite well of this wire.
I'm not sure at what revision of manual and or schematic you're looking, but on the 464 manual that I have, it's really easy to spot this connection at both its ends.
On diagram 3, VERTICAL SWITCHING, it's on the right side, a little bit above half of the page. from top to bottom, it's the first outgoing connection just after the outputs to the delay line, coming out from one of the ganged switches actuated by the TRIG-VIEW button. It gets connected to +15V when TRIG-VIEW is pressed, and it goes to R691 on diagram 5.
On diagram 5, A&B TRIGGER GENERATOR, this connection show on the very bottom of the page, just above the "A&B TRIGGER GENERATOR <5>" diagram title.
When the TRIG-VIEW button is pressed, the +15V coming through this wire is what actually provides power to the TRIG-VIEW output buffer, which will source the TRIG-VIEW signal.
It's not clear to me though, why Tek chose to switch the power going to this small output stage, since its output is further switched by the remaining contacts of the TRIG-VIEW switch.

On the 466, I have only a PDF copy of a later revision (whose channel select circuitry is similar to the 465B and 468) and there doesn't seem to exist this wire, as the whole TRIG-VIEW circuitry is completely different.

On the 465, at the source of the signal (red wire) it's represented exactly the same as I described above for the 464, and in the same location of the VERTICAL SWITCHING <3> diagram, with the only difference that the wire is not connected directly to the board, but by means of a connector pin, P337.
Yet on the 465, at the other end of this wire, it's different from the 464 schematics, because Tek chose to draw the Trig-View amplifier on a different diagram <11>, and there are a few differences in what the +15V coming through this wire actually does. On the 465, it only apply bias to the Trig-View amplifier input transistors (while the output transistors get continuous +15V supply).

Regarding the scope being with DM44 or without it, I don't think it matters whatsoever to this circuit.

Last but not least, regarding the two different versions of the custom Triggering Amplifier IC, 155-0032 or 155-0217, I don't think it matters if with or without DM44t... There's nothing about this IC that holds any relation to the DM44 being installed or not.
When I got my 464, its trigger was not working well, and it had 2 different versions of this IC (A time base had the older, B time base had the newer).
It was one of my first questions to this group, back on 2016, whether there was any difference between them (that could justify my A trigger was not working well) but soon enough I discovered that my problem was due to a leaky FET (at the A trigger input stage). The leaky FET was causing a DC offset at the input of the Trigger IC, beyond of what it can handle.
After I located and repaired the guilty FET, I was able to even swap the ICs between A and B, and they proven to be interchangeable to the point of barely affecting the trigger calibration / adjustments...
From the answers I got from the group back then, IIRC, the only difference between them is that the later one is made on a newer silicon process. They're equivalent and interchangeable.

KRgrds,

Fabio

On Sun, Jul 22, 2018 at 03:59 AM, Jim Olson wrote:


This inquiry is for the more knowledgeable folks on these scopes..
I have noted that there is a small red wire strung through the main harness
from the switch pre amp to the trigger - Z axis board connected from a pad by
the J338 coax connector and then on bottom of board to the S338B trigger view
switch.
On the 466 w/o the DM44 and the 464 with DM44 it is connected to a pad just in
front of Q682 this done on both the 670-3324-00 and 670-3324-01 boards with
the 155-0032 chips and the 155-0217 chip on 464 w/DM44 this is listed as a
replacement chip for the 0032. (any one know what the diff is for the two
chips?) On the 465 with DM44 and board 670-2234-04 with the 155-0032 chip it
is connected at a pad by resistor on lower edge of board in a resistor network
unmarked about 1.5" in front of J688.
I am guessing that this wire is for the trigger view? I cannot find it on the
schematics anywhere.

Jim O


Re: Homemade tunnel diodes

thespin@...
 

Modern mixer diodes are great but I have yet to find a good replacement for step recovery diodes.


Re: Schematic/PCB KiCAD 5 is finally out and available

John Griessen
 

On 07/23/2018 10:44 AM, walter shawlee wrote:
Gentlemen,
Schematic/PCB software 5.0 from KiCAD, the massively powerful,
For people who like using linux and scripting and make files, (like chip designers),
pcb-rnd is rapidly becoming a complete toolkit for making blind buried vias,
defining groups of circuitry that move as one, searching for data in layout and extracting
parasitics. The autorouter is soso, but there is another one and ways to use external ones also
in the works. Schematics are possible to come from Kicad or gschem.
You can import a netlist from eeschema and keep using eeschema, or switch to gschem if not a Kicad user already.

pcb-rnd will not force upgrades on you ever -- older formats of files are going to be supported if anything changes.
No upgrade treadmill.


Re: 7603 specifically and general refurbishment procedures of older oscilloscopes

Artekmedia <manuals@...>
 

If it works with the 7L12 but not with known good regular plug-ins. More than likely don't have the right buttons pushed ( or a bad button) . Take a deep breath and check that you have the trigger selector set correctly for the channel your on and so forth.

Beam finder works correct?
Dave
manuals@...

On 7/23/2018 11:57 AM, johnasolecki@... wrote:
Hello everyone,

I recently acquired a 7603 with 7L12 SA. I got the pair to use the 7L12 with my 7904A but I really like the large screen of the 7603. So I'm planning to use the '03 for audio work. The '03 seems to work when the 7L12 is installed but I can't get any kind of trace (except for readouts) when I use any of my 7000 series plug ins. I can't say I've tried every permutation but I've tried installing a 7A19, a 7A22, 7A26 in conjunction with a 7B92, 7B92A, 7B80 and a 7B85 with the "A" plug ins in the center & left slot and the "B" in the right with no joy.

Because of this problem I'll be opening up the 7603; if anyone has any specific suggestions on where to look I'd be grateful but otherwise are there any common procedures for the overhaul of an older scope? I have quite a bit of experience rebuilding older amplifiers and radios but I bought my 7904A refurbished, I have no experience on older Tek scopes. I thought I'd start by cleaning the plug in connectors and as many pots & switches as I could access. While open I will check voltages and have a good look at the caps.
Do you automatically replace all electrolytic caps or just ones that are showing signs of ripple or leakage?
A search of the files section implied that tantalum caps are usually reliable and do not require preventative replacement (other than obvious failures).
Are there any other common issues that need to be looked at? Any other suggestions?

This will take me a while to complete but in the meantime, thanks in advance for any help,

John


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


7603 specifically and general refurbishment procedures of older oscilloscopes

johnasolecki@...
 

Hello everyone,

I recently acquired a 7603 with 7L12 SA. I got the pair to use the 7L12 with my 7904A but I really like the large screen of the 7603. So I'm planning to use the '03 for audio work. The '03 seems to work when the 7L12 is installed but I can't get any kind of trace (except for readouts) when I use any of my 7000 series plug ins. I can't say I've tried every permutation but I've tried installing a 7A19, a 7A22, 7A26 in conjunction with a 7B92, 7B92A, 7B80 and a 7B85 with the "A" plug ins in the center & left slot and the "B" in the right with no joy.

Because of this problem I'll be opening up the 7603; if anyone has any specific suggestions on where to look I'd be grateful but otherwise are there any common procedures for the overhaul of an older scope? I have quite a bit of experience rebuilding older amplifiers and radios but I bought my 7904A refurbished, I have no experience on older Tek scopes. I thought I'd start by cleaning the plug in connectors and as many pots & switches as I could access. While open I will check voltages and have a good look at the caps.
Do you automatically replace all electrolytic caps or just ones that are showing signs of ripple or leakage?
A search of the files section implied that tantalum caps are usually reliable and do not require preventative replacement (other than obvious failures).
Are there any other common issues that need to be looked at? Any other suggestions?

This will take me a while to complete but in the meantime, thanks in advance for any help,

John


Re: OT: HP 70843B Error Performance Analyzer, 12 GHz BERT info needed

garp66
 

hi Ed,

I believe that I had seen free .pdf manuals for the HP 70843b Error Performance Analyzer at the Kurt manuals site:

https://doc.xdevs.com/doc/HP_Agilent_Keysight/index.htm


However, a small quick start manual is available at the Keysight:
https://www.keysight.com/en/pd-21967-pn-71612C/error-performance-analyzer?pm=PL&nid=-536900202.536882650&cc=US&lc=eng

Also, someone on the EEVblog may have some info on it:
https://www.eevblog.com/forum/testgear/agilent-70843-12gbits-error-performance-analyzer/

An HP blurb about it:
https://d3fdwrtpsinh7j.cloudfront.net/Docs/datasheet/hp_71612b.pdf

Cables:
The DB-37 pin HP MSIB cables can simply be made with crimp-on flat ribbon cable connectors:
http://www.rbarrios.com/projects/HP-MSIB/


Let me know,
rick


Schematic/PCB KiCAD 5 is finally out and available

 

Gentlemen,

Schematic/PCB software 5.0 from KiCAD, the massively powerful,
long awaited, auto-routing and multi-OS integrated package, with better libraries and 3D models
is now on their site for download. Also available in many languages, see the localization support.

and yes, *free*, funded by CERN. this is a great public milestone,
and very useful for guys like me that are not on Windows,
as it runs on Ubuntu and many other LInux platforms (Debian, Mint, Suse and more) as well as Apple
and Windows. This software is why several wildly over-priced commercial packages
have had huge discounts recently, the days of the abusively over-priced $5K PCB CAD seat are
running out. Eagle guys can import designs directly. It now also links to Ngspice.

see:

*http://kicad-pcb.org/blog/2018/07/KiCad-5--a-new-generation/*
for all the details. This is a great moment for designers that
have not had a good tool that runs outside of windows, or one they could
afford for personal use.

all the best,
walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
We're all in one boat, no matter how it looks to you. (WS2)
All you need is love. (John Lennon)
But, that doesn't mean other things don't come in handy. (WS2)


Re: Tek bits

David Berlind
 

Is there a complete inventory list?

On July 23, 2018 7:52:01 AM "Andre de guerin via Groups.Io" <testing_h=yahoo.com@groups.io> wrote:

Hi, in my shed I have a lot of Tek bits including very hard-to-find long pots.have a few flybacks but not sure what state they are in.
Anyone have a use and want to pay postage only?
_A


Re: Tektronix DM5010 NiCa 2.4V battery replacement

Ke-Fong Lin
 

Hi everyone,

Ok, I've created a photo album ("DM5010 NiCad battery replacement info") with the battery schematic part and spec of the CMOS RAM.

According to the DM5010 manual, the battery is to be replaced every 2 years.
Procedure is to let the DM5010 running 24h for the battery to fully charge, and then do the calibration.

The CMOS RAM (U1220) that is battery backed, is a HMI-6562-9 (Harris).
According to the specification, the data retention supply current is 10uA max.
For a 110mAH, that would be (110 / .01) = 11000 hours (458 days) for full discharge?
At least, the battery should handle a month or two, I guess?
Correct me if I'm wrong.

Also, according to the schematic, we have a current limit of around 24mA (R1135 limiter resistor at 100R for around 2.3-2.4V) for the trickle charger.
But the trickle charge would be quite high as R1131 is only 100R. Let's say BT1121 is 2.4V and CR1133 cathode is 5V, that would be around 24mA.
Even for the original battery spec'ed at 150mA, trickle charge should be C/10 = 15mA.

My planned replacement battery is spec'ed at 4mA for trickle charge, should I replace R1131 by a 680R resistor? This would give around 3.5mA max.

Thank you for your comments.

Best regards,


Re: Tek bits

Craig Sawyers <c.sawyers@...>
 

Hi, in my shed I have a lot of Tek bits including very hard-to-find long pots.have a few flybacks
but not
sure what state they are in.
Anyone have a use and want to pay postage only?
_A
Where on planet earth are you?

Craig


Tek bits

Andre de guerin
 

Hi, in my shed I have a lot of Tek bits including very hard-to-find long pots.have a few flybacks but not sure what state they are in.
Anyone have a use and want to pay postage only?
_A