Date   

Re: Tek 154-0235-00, where does it belong to?

Dave Wise
 

30 seconds of looking at the 154 Replaceable Parts Record, available for free download at w140.com .

154-0235-00 is for the 531A, 533, 533A, and 535A. (I believe it can also be used in the 531 and 535, perhaps with a small circuit modification.)
It’s P15 phosphor, which is not the usual type. It’s green with short persistence where the usual type is P2 or P31 which are medium persistence. Tek said P15 was for “Television pick-up of photographs by Flying Spot Scanning.”

HTH,
Dave Wise

From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Joe via groups.io
Sent: Wednesday, July 07, 2021 1:30 PM
To: TekScopes@groups.io
Subject: [TekScopes] Tek 154-0235-00, where does it belong to?

Hello,

I have been offered a crt Tek 154-0235-00, NOS boxed. Can anyone id to which scope it would fit?
Thanks for replies!

Regards, Joe


Tek 154-0235-00, where does it belong to?

Joe
 

Hello,

I have been offered a crt Tek 154-0235-00, NOS boxed. Can anyone id to which scope it would fit?
Thanks for replies!

Regards, Joe


Re: RSA 3408 A Real time spectrum analyser

 

RSA3408A, actually manufactured in this century, is almost a contemporary instrument (compared to much of what is discussed in this group). Considering that spectrum analyzers seem to retain their value much longer than scopes, I would expect that a reasonable asking price (for a working unit) to be in the same range as the original retail price.

That said, the most recent catalog that I could find was from 2000 and an 8GHz spectrum analyzer (the R3465) cost $32,995 (base model). If we just scale that up for inflation we get $51,580. So I'd guess that the expected price for a used (and working) SA of relatively recent vintage would be at least $5,000-$10,000.

Disclaimer: I'm not very familiar with spectrum analyzers, so I'm not confident that the R3465 is a good analog for the RSA3408A, which has a much lower frequency floor.


Re: My 475

Mark Vincent
 

Rey,

I had a Z problem that was one coax connector that needed to be moved up and down in its socket a few times. I had all other voltages correct, nothing on the screen. After that one coax was moved to make contact, it worked. I move connectors in and out while having 90% IPA on it to help clean the pin and socket. I have seen enough of these look clean yet were not making contact. Of course these are done one at a time so no mistake in where that wire/cable goes.

Checking the main power supply voltages is always the best place to start. Those should be adjusted, if necessary, to the specs. The high voltage can be checked by putting the back of your hand near the hv wire insulation. You will not get shocked this way. The presence of high voltage will make the hairs move. A crackle sound at turn-on is another way to know the voltage is there provided that sound is made. No danger of that sound.

Check the oscillator transistor for the high voltage. With the fuse being good, it could have opened internally. I know this is unlikely but it would confirm that transistor. Another way is to see if you have a-c voltage at the collector of the transistor. If so, you should have the high voltages and heater voltage. You should see about 50-60VAC p-p at the collector.

Jeff is right about tracing the signal until you lose it and possible dirty contact(s).

Mark


RSA 3408 A Real time spectrum analyser

Anil Nediyara
 

I have been offered a Tek RSA 3408A RTSA in reasonably good condition with a years calibration certificate (NABL accredited) I would like to know if any of our members could help me find a realistic price for thd same. I have been receiving astronomical figures from online used gear suppliers.

Thank you
Regards
Anil


Ran in to these on E-bay.

Zentronics42@...
 

I am not the seller but I know these are sought after for those that have the scope that needs them Price seems good.

https://www.ebay.com/itm/194221438414?hash=item2d387ff5ce:g:4C0AAOSwGtJg26IS

Zen


Re: 7603 P.S. cans, slow warm-up and focus control

Mark Vincent
 

Guys,

I already checked the crt using my 752 tube tester with the settings to a TV B/W crt. It comes up normally and tests fine. I tested other Tek. crts that come up faster. The readings were close in emission and time to come up. I know TV repair very well and miss working on them. Before I posted my question, I already checked things. The only original parts not changed yet are the input filter cans. The line on the screen does have intensity modulation moving from right to left with no signal. When the time base is set a line trigger, the modulation movement stops. That is what makes me suspect the original filter cans are going bad. The electrolytics at and beyond the regulators are new with many higher in capacitance. I already checked the high voltage and Z sections. Those voltages are right.

Why the focus pot burned is that 150V across 50,000 ohms is ,45W dissipation with the control being ,5W. That is 90% of the capacity causing a temperature rise of 225C above ambient. I have had other pots in other scopes and plug-ins for 500 series being run this hard or over the power rating of the controls. I added resistors on each side to reduce the power dissipation. These controls are the horizontal and vertical position controls. I still have enough control range after the addition of resistors to reduce power. The Radiotron Designer's Handbook says resistors not be run in power over 1/2 its power dissipation plus ambient temperature in the calculation. Running a resistor at its power rating causes the resistor to raise 250 deg. C above ambient. By what the book says, ambient plus the dissipation should not be over 125 deg. C. I assume 40-50C ambient in operation leaving a rise of 75-85C. This is a third of the 250C so multiplying the power being dissipated by 3 1/3 gives the power rating of the resistor that should be used. Going to 4x larger gives headroom. If the power at 4x is, say 2.2W, then a 2W is used. An example of a underrated power resistor was in an RCA CTC36/7. The 600ohm 18W under the chassis under the high voltage cage was a known problem. It would burn the wire insulation, become open circuit, burn the red fiberglass terminal strip causing that strip to be replaced. A pair of 1200 ohm 25W in parallel is what I used. Now using a transistor or two with resistors and zeners will drop the voltage (series pass) in these types of places. I have done this in a Zenith 14DC15/16. It works fine. I will restuff the cans soon to complete the restoration. The 15NP22 crt was replaced with new and may have five hours on it now.

Zen, thanks for the note on the two connectors to not switch. I will make sure they are put back right before powering on after the work is done. I still think the cans going bad are the problem that soon will be confirmed when replaced. I want to see if anyone had seen cans going bad in this series causing this problem. Usually when the filters go bad, it is obvious.

Thanks for the replies and advice. I appreciate it.

Mark


Re: My 475

Rey
 

Correct no image on the crt or even using the beam find. But all the other switching(lights) on the face panel work. I'm trying to figure it out, and I love all the input and help from you guys. I been out of the electronics game forever, but I'm smarter than the average bear. The tektronix troubleshooting manual, stated about injecting a - 10-15V for about 10" using the EXT z input, thats my next step. By the way is a pretty cool manual, very clear and step by step still lots of scope lingo but I'll keep at it.


Re: Members in Australia

doyle.paul48
 

G'day John,
You can add me to the Aussie group.
I believe I have been an interested member to the group for at least the
last 20 years.
I cut my teeth on TV Waveform Monitors, and had extensive experience on
tube based displays for the last 5.5 years
I display my wares at all the key amature radio field days in Eastern
Australia pre covid.
Regards
CROTEK.
Sydney Australia.


Re: FTAGH: Free to a good home: 465/475 scopes

Jim Strohm
 

As far as shipping via UPS? ALWAYS insure for something far higher than
cost, declare it as FRAGILE ELECTRONIC EQUIPMENT, <whatever it is>, and
have the UPS counter (NOT a UPS storefront) verify the packing. Then if it
gets dropped, the recipient gets his money pack, UPS takes away the
destroyed unit, and you make a big profit.

I lost a historically significant Sun engine scope to UPS once and made
$400 after repaying the seller and eating the shipping. On another note,
my company had a remote site ship a hincky-acting desktop PC pack to us for
repair, and UPS craterd it. However, they took the minimum (free)
valuation of $100, and we received a destroyed $1800 PC. This was back
when white-box PCs were worth something.

And then there was the 4-foot-long slender cardboard box of miniblind
valances that arrived, tied in a pretzel. The common denominator was, as
my father-in-law noted when the valances arrived, was "So your company name
is pronounced 'OOOPS' right?"

Given a chance, UPS can and WILL destroy almost anything fragile, no matter
how well it's packed. It's why those G-force indicator labels were
invented.

73
Jim N6OTQ


Re: 7603 P.S. cans, slow warm-up and focus control

Zentronics42@...
 

One thing to note on the 7603, if you remove the power supply Take LOTS of photos and triple check the connectors before turning the scope on. There are 2 connectors in particular that need attention. I am not in the lab at the moment so I can get the numbers later tonight. but looking from the back of the scope they are left side and up top on the top most board. The is the distribution point for the LV supply and also the test point for the LV voltages. DO NOT get the 2 back to back connectors reversed. The scope will be destroyed. What happens is the 130 V rail gets fed in to most of the IC's in the wrong place frying all of them. If I remember correctly the connectors are tan and black.

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Jean-Paul
Sent: Wednesday, July 7, 2021 7:27 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7603 P.S. cans, slow warm-up and focus control

Mark: My 7603 is like all other TEK scopes I have, normal warmup time.

Your symptoms sound like old caps in LV and HV PS, also check the Z axis circuit.

WHY did the focus pot burn: A big clew !

Suggest to get a HV probe or VOM DVM adapter, and go thru all voltages in the HV/CRT ckt.

The HV transformers are suspect on some old TEK scopes due to cracking or deteriorating insulation.

Bon Chance

Jon


Re: Members in Australia

Dean Davidson
 

On 6/07/2021 12:51, penguin2004au wrote:
Greetings all:
Just curious to see how many members are Down Under, if only because I might
have to downsize my collection soon.
John,
I am in Armidale NSW.
Now... Where are you???

Dean
VK2DJD


Re: FTAGH: Free to a good home: 465/475 scopes

Jeff Davis
 

Hi all,

It appears that I’ll have no trouble finding homes for all of these scopes. Accordingly, I’m going to revert to my “local pickup only” policy. If we have already discussed shipping, then of course I’ll honor my commitment but it’s local pickup from here on out.

Regarding the below, if I’m shipping a scope to you, it’s your call whether to use Fedex or UPS. I can take the scopes to either place.

Thanks for understanding!

73,
Jeff / N0DY

On Jul 6, 2021, at 10:23 PM, Gordon Smith <gfsmith@cox.net> wrote:

Hi Jeff,
I must most strongly advise you to NOT ship this scope (or any other item that can be broken) via UPS. Having them pack it is fine, but please do not ship via UPS. I and many others have had nothing but bad experiences with them for breakable items. As was recommended to me once, if you are shipping something with UPS please pack assuming that your item will be dropped 12 ft onto a hard concrete floor. And I am not joking. If you really want the scope to make it through the mail, please please ship via Fedex or USPS. That is just my experience, YMMV.

73, Gordon KJ6IKT

On Tue, Jul 6, 2021 at 03:36 PM, Jeff Davis wrote:
Sure, I can do that, no problem. If it makes no difference to you, the UPS
store is somewhat more convenient for me.

Jeff
On Jul 6, 2021, at 3:29 PM, greenboxmaven via groups.io
<ka2ivy=verizon.net@groups.io> wrote:

Would you be willing to take one or two of the scopes to a Fedex store,
they can pack and ship them with no further effort on your part and I can do
all of the payment from my end. Thanks,

Bruce Gentry, KA2IVY




Re: 7603 P.S. cans, slow warm-up and focus control

Jean-Paul
 

Mark: My 7603 is like all other TEK scopes I have, normal warmup time.

Your symptoms sound like old caps in LV and HV PS, also check the Z axis circuit.

WHY did the focus pot burn: A big clew !

Suggest to get a HV probe or VOM DVM adapter, and go thru all voltages in the HV/CRT ckt.

The HV transformers are suspect on some old TEK scopes due to cracking or deteriorating insulation.

Bon Chance

Jon


#file-notice Tektronix PRISM GPX3001 w/ 32GDP logic analyzer #file-notice

lostinfailure
 

Hi everyone!

This is my first post here, I am an embedded systems engineer and I do quite a bit of electronics.

I had the opportunity to get a GPX3001 logic analyzer with one 32GPX module for a good price. It came with a lot of accessories. It has the following options:
- Harddisk plus Keyboard (1Z)
- Real-Time Performance Analysis 32PA (1A)
- Upgrade to 32k Memory/Channel 32GPD (1S)
- RS-232 Communication Pack (1C)
- GPIB Communication Pack (2C)

It came with 4 P6490 probes, 80 data leads total.

I also got 2 binders full of documentation in physical form (which I scanned):
- instructions-1200c01-rs_232c_comm_pack-070-6675-02.pdf
- instructions-1200c02-gpib_comm_pack-070-7415-01.pdf
- instructions-goscript-postscript_language_interpreter_software-061-4032-01.pdf
- release_notes-prism_30c02-general_purpose_interface_bus-061-3857-01.pdf
- release_notes-prism_32gpx-acquisition_module-061-3893-03.pdf
- release_notes-prism_32pa-performance_analysis-061-3916-00.pdf
- release_notes-prism-system_software-070-8009-11.pdf
- user_manual-prism_3001-system-070-6672-04.pdf
- user_manual-prism_30c02-general_purpose_interface_bus-070-8008-00.pdf
- user_manual-prism_32gpx-acquisition_module-070-8465-00.pdf
- user_manual-prism_32pa-performance_analysis_software-070-8494-00.pdf

Since I found very little information on that beast, I took the time to scan everything and run the OCR on the resulting PDFs. I also dumped all the floppies. I put everything on archive.org here:
https://archive.org/details/tektronix_gpx3001

I have some advertisement and guides that I haven't scanned yet. I may add them to the archive when I find some time.

I also opened the device and found that the IDE hard drive interface board is very simple: one DIP IC and a handful of resistors. I haven't dismantled everything but on a first look I think that it could be easily recreated.

With that out of the way, I have a problem with it. The 32GPX application SW refuses to load. I tried multiple ways:
- Boot system from hard drive, insert 32GPX SW floppy and use the Load Application feature from the SAVE/RESTORE menu: "Load application operation failed."
- Install the 32GPX SW from the floppy disk to the hard drive. The installation succeeds but when I reboot, software isn't found. Manually loading from the HDD fails also.
- Disconnect the hard drive and boot. Load System SW from floppy at boot, succeeds. When prompted for Application SW, put in the 32GPX floppy. Loading starts and after a while says that no software could be found:
"Software has not been loaded for: GPX1".

I tried recreating a new 32GPX SW floppy disk, thinking the signal degraded after 25 years:
- I found an old 3.5" 1.5MB
- I taped the left-corner hole
- I formatted it to 720KB inside the PRISM GPX3001
- I used an old Linux computer to perform a low-level copy of the original floppy using dd

The duplicated floppy gives the exact same behavior as the original. Other programs from other floppies load fine.

I ran both the system and the GPX32 diagnostic tools and have no error (except from an RS232 loopback test failing which I assume is safe to ignore).

From these experiments, I know this is not a hard drive problem/filesystem corruption. I also believe that the floppy disk is likely intact since it is in very good condition and I had no error while dumping the disks.

This leads me to believe there is something wrong on the hardware level, or I have the wrong software. Unfortunately, the 32GPX SW was not installed on the hard drive. I don't understand why since, according to the documentation, this should have come pre-installed from the factory.

It appears that a user from this group had the same issue and was able to work around it a while back (12 years ago!!): https://groups.io/g/TekScopes/message/42138 . I hope that someone here remembers what it was? I think that this user is still active here.

PS: I have just noticed, after having written all of this, that some GPX3001 binaries are available on http://www.ko4bb.com. There are even ROM dumps! I will have a look at these tomorrow. I may try to disassemble the ROM files to see where the error might come from.

Thank you for reading me and I hope someone will find the archive useful.

All the best


Re: My 475

 

Rey,

Sorry to belabor this point, but I am legitimately confused: are you saying that there is absolutely no image on the CRT?

If that is the case, I would begin to suspect the HV supply. You will need an HV probe to check that as it runs at 2500 V.

I wonder, however, if there is a failure mode of the Z-axis amplifier that could completely blank the display. I only say this because I've had a 475 with trouble in the Z-axis amp, not because anything specific about your case suggests it. Also, the Z-axis amp would be easier to diagnose than the HV supply, but that's also a terrible reason to go down that road.

Finally, you could apply a signal to the vertical inputs and trace the signal through the attenuators and vertical pre amps to the channel switch. The fact that you have lost both signals at the same time suggests that the failure is after the channel switch. It could be as simple as dirty contacts on the channel switch IC's pins, or the channel switch IC might be dead. I'll take a look through the schematics to see what else might interrupt the signal between the channel switch at the CRT.

-- Jeff Dutky


Re: Members in Australia

romeo987
 

John,
Tek (and other “vintage” stuff) fan here in Adelaide. Would be interested to know what you have.
Roman


Re: Members in Australia

Simon Owen
 

Sydney, 2131. And helplessly addicted.

On Tue, 6 Jul 2021, 12:51 pm penguin2004au, <clansman2011@gmail.com> wrote:

Greetings all:
Just curious to see how many members are Down Under,
if only because I might
have to downsize my collection soon.
Regards: John.






Re: 7603 P.S. cans, slow warm-up and focus control

emissionlabs
 

This is just from the days when I did TV repair. I don't know if it applies to TEK CRT.

Provided all voltages CRT are good (including heater voltage) perhaps the cathode has reduced emission. Initially that gives little problems. There are ways to find this out quickly, leaving everything in place.


Re: Members in Australia

David Hopkins
 

I'm also here in Australia.
Up in Queensland.

David

On 2021-07-07 2:58 pm, VK1GVC wrote:
John et al, I'm in Aus, in Canberra.

And what's with this Melbourne/Vic thing?  All geographically identifiable replies below seem to be from your part of the world!

Regards,

Graham

On 6/07/2021 12:51 pm, penguin2004au wrote:
Greetings all:
                      Just curious to see how many members are Down Under, if only because I might
                 have to downsize my collection soon.
Regards: John.







--
Definitely not sent from an I-Phone

David G Hopkins (VK4ZF)

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