Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Tek folks,
The seller as acknowledged my offer and I will be making arrangements to get the lot.
Most likely I will store them near Greenfield till they can be sorted and moved on to folks who want them.
I'll keep the list posted.
Roy Morgan
K1LKY Western Mass
607-765-8867
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-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Roy Morgan
Sent: Monday, September 07, 2020 8:20 PM
To: [email protected]
Subject: Re: [TekScopes] Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Tek folks,
I am working to put together a deal for these scopes (I am on western mass in striking distance of the NH seller)
Goal is to get the lot and pass along scopes to interested list members, covering just costs. )
I will make offer to buy the lot and keep the list posted.
Roy
Roy Morgan
K1LKY Western Mass
On Sep 7, 2020, at 10:36 AM, David Berlind <david@...> wrote:
?For sale in NH for $450. I am not affiliated with the seller.
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Re: 10 EASY WAYS TO TROUBLESHOOT WITH AN OSCILLOSCOPE
Looking at the author's site, it *appears* that he has good intentions, and enjoys learning about a wide variety of things, but lacks actual expertise/experience (at least in electronics).
He may not realize that a scope is NOT essentially an auto-ranging DMM, and that advising newbies to make AC line measurements is a Bad Idea.
Pete
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Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Tek folks,
I am working to put together a deal for these scopes (I am on western mass in striking distance of the NH seller)
Goal is to get the lot and pass along scopes to interested list members, covering just costs. )
I will make offer to buy the lot and keep the list posted.
Roy
Roy Morgan
K1LKY Western Mass
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On Sep 7, 2020, at 10:36 AM, David Berlind <david@...> wrote:
?For sale in NH for $450. I am not affiliated with the seller.
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
Hi Barry
Thanks for the prompt response. I'll let you know how I make out.
Harrison N1FAM
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
Michael. Thank you for your pictures and explanation. Your repair looks very professional and obviously was effective. Unfortunately I don't have access to a 3D printer for the enclosure. I am thinking maybe I can use a craft store plastic container or a small pill bottle. I am not familiar with the Tek X Ref catalog but will search for it on line. Building a replacement circuit will be new for me. I haven't done that in the past. I am good at parts replacement. So circuit building will be new for me. From your pictures it appears your new circuit is spliced into the red line going to the CRT. Thanks again for the information. I was thinking of shelving the 465M because I didn't have a replacement U550 but you motivated me to perhaps carry on. My functional scope is a Tek TDS460A. The 465M is strictly a bench and learning exercise/project. The scope was given to me as excess and not working. I do have a "parts" 455 but I was trying to save it so that if I got educated and repaired the 465M I might be able to bring the 455 back just for the exercise. The 455 U550 doesn't seem any better so I haven't considered swapping it out. It did look good at one point but no longer. It appears to be blowing the F736 fuse. Don't know if that is the result of my probing or if something just gave up once it was powered up for a bit. Before it was blowing the F736 fuse It didn't have a trace but did have a beam finder. The 455 also spent some time under water years ago so that certainly didn't help it. Enough on the 455. Thanks again for the information. Harrison N1FAM
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
Hi Harrison,
Yes, that all sounds correct.
From the symptoms your scope is exhibiting as compared to mine and others, the multiplier is likely arcing inside when it gets up to working voltage. As far as I know, this is fairly common failure in the 465M's multiplier.
Good luck with it.
Thanks,
Barry - N4BUQ
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----- Original Message ----- From: "Harrison" <buma7@...>
To: [email protected]
Sent: Monday, September 7, 2020 6:30:40 PM
Subject: Re: [TekScopes] Tek 4654M; No Trace, No +5V, No +95V; Help
Barry, Thank you for the picture and explanation. I believe it is pins 8, 9,
and 10 of T550 that relate to U550. It looks like pin 8 goes to the PCB.
Pins 9 and 10 go to U550. I wanted to confirm that to disconnect the
multiplier from T550 it was just the end connection (the one closest to the
board edge) that you disconnected, That would be the U550 connection that
mates with T550 Pin 10. Is that correct? Once I unsolder that connection I
would replace the F558 fuse and power up the unit to see if the fuse doesn't
blow and the 95V bus is back. Harrison N1FAM
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Re: Tek 4654M; No Trace, No +5V, No +95V; Help
Barry, Thank you for the picture and explanation. I believe it is pins 8, 9, and 10 of T550 that relate to U550. It looks like pin 8 goes to the PCB. Pins 9 and 10 go to U550. I wanted to confirm that to disconnect the multiplier from T550 it was just the end connection (the one closest to the board edge) that you disconnected, That would be the U550 connection that mates with T550 Pin 10. Is that correct? Once I unsolder that connection I would replace the F558 fuse and power up the unit to see if the fuse doesn't blow and the 95V bus is back. Harrison N1FAM
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Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Oops. Sorry about that. Where was my head? Yes Siggi, you got it right.
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On September 7, 2020 11:33:45 AM "Siggi" <siggi@...> wrote: Looks like this is the ad:
?
On Mon, Sep 7, 2020 at 11:11 AM greenboxmaven via groups.io <ka2ivy=
[email protected]> wrote:
How can I see the posting or contact the seller?
Bruce, KA2IVY
On 9/7/20 10:36 AM, David Berlind wrote:
For sale in NH for $450. I am not affiliated with the seller. But at $45 per scope plus the scopemobiles, that seems like a pretty amazing deal.
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Help troubleshooting a 2710 SA
Hi,
I recently obtained a 2710 SA in non-working state and I am trying to repair it.
The problem is (well, there may be more than one problem, but this is the one I can observe at this stage) the display is showing only a dot in the lower-left corner.
If I increase the intensity, I *think* I can see something more: some faint dots somewhere on the leftmost vertical line of the screen.
So, my first suspicion would be that horizontal deflection and/or sweep is not working.
But, before I did anything else, I wanted to check the power rails and this is where I am at the moment: the voltages are around the values mentioned in the service manual, but ripple is significant (even the mV part of the DC readings on the meter is fluctuating).
I also checked the voltage on the main filter cap (i.e. C380F) and noticed huge ripple (over 50V pk-pk), even with all the boards removed from the chassis (the CRT was still powered, though).
As the next step in my investigation on the cause for this ripple, I was pondering powering the supply board on its own (i.e. not plugged into anything, apart from the mains), but I'm not sure if this is something ok to do (i.e. any risk something might get damaged, if there is no load).
Any suggestions on this, please?
Thanks!
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Re: 10 EASY WAYS TO TROUBLESHOOT WITH AN OSCILLOSCOPE
please research the author first before debating the article !
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Re: 10 EASY WAYS TO TROUBLESHOOT WITH AN OSCILLOSCOPE
Yes, the guide seems to be lacking common sense. The comment measuring the line voltage (and frequency) brought a smile. I remember back 40 years or so ago an instructor at a well known university was attempting to show class the waveforms on a triac circuit. I walked out after he connected the scope ground to the hot line and tripped a breaker. Unfortunately, I missed the greater fun, when (I heard later) he managed to get himself connected to the hot side of the line while holding a grounded microphone. The mic went flying....
The suggestion that a scope can be used as an autoranging DMM does not apply for most of the scopes folks have in this group. None of the half dozen scopes I have are autoranging, connecting any of them to line voltage without careful understanding of settings and probe limits would likely result in damage.
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Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Siggi,
I am near NH and would be glad to participate in a shared purchase.
I could use one (maybe two) scopes and a cart. No room for much more.
Roy Morgan
K1LKY Western Mass
Near Greenfield.
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On Sep 7, 2020, at 11:33 AM, Siggi <siggi@...> wrote:
?Looks like this is the ad:
?
On Mon, Sep 7, 2020 at 11:11 AM greenboxmaven via groups.io <ka2ivy=
[email protected]> wrote:
How can I see the posting or contact the seller?
Bruce, KA2IVY
On 9/7/20 10:36 AM, David Berlind wrote:
For sale in NH for $450. I am not affiliated with the seller. But at $45 per scope plus the scopemobiles, that seems like a pretty amazing deal.
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Re: 10 EASY WAYS TO TROUBLESHOOT WITH AN OSCILLOSCOPE
Well this article assumes you know something about connecting a scope to a
live AC circuit. A differential probe is a great starting point. Also
using a battery powered scope and a making certain no path to ground
exists.
This message sent to you from my mobile device via speech-to-text
technology.
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TM500 Mainframe common problems for each model?
Hi,
I have a number of TM500 mainframes here I'm working through restoring alongside my collection of modules and I've seem mention of each mainframe having certain quirks and things to look out for and replace etc.
Can anyone with experience with these units list off the common faults you've seen and improvements you've made for the different mainframes?
I currently have 3x TM501, a TM503, a TM503B and a TM5006.
Thanks!
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Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
Looks like this is the ad: ? On Mon, Sep 7, 2020 at 11:11 AM greenboxmaven via groups.io <ka2ivy= [email protected]> wrote: How can I see the posting or contact the seller?
Bruce, KA2IVY
On 9/7/20 10:36 AM, David Berlind wrote:
For sale in NH for $450. I am not affiliated with the seller. But at $45 per scope plus the scopemobiles, that seems like a pretty amazing deal.
|
Re: Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
How can I see the posting or contact the seller?
Bruce, KA2IVY
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On 9/7/20 10:36 AM, David Berlind wrote: For sale in NH for $450. I am not affiliated with the seller. But at $45 per scope plus the scopemobiles, that seems like a pretty amazing deal.
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Lot of 10 scopes (400s & 2400s) with 5 scopemobiles
For sale in NH for $450. I am not affiliated with the seller. But at $45 per scope plus the scopemobiles, that seems like a pretty amazing deal.
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Re: EZGPIB and TDS744a screen dump ...
Dave,
Would you be willing to share the details if your solution?
George
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On Sep 6, 2020, at 11:51 PM, David Slipper <softfoot@...> wrote:
I gave up on EZGPIB and wrote something in FreeBasic that does the job nicely.
Dave
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The 4041 Utility ROMpack R04 manual on bitsavers has a couple of interesting rom calls:
- Loadroms is a Soft ROMpack loader that could load ROMs from a file on tape or disk into memory (pg 1-1)
- PROM File System allows ASCII or ITEM files to be read from PROMs as device name PROM0 which is read-only but supports all the BASIC commands other than SAVE (also on pg 1-1)
Two problems with the PROM file system - the Tektronix ROM Carriers are 'almost unobtainable' although I have found two different sources the price is over $50 for a single plastic cover with two EPROMs in the Molex carriers. Second problem is the PRMBLD and RMXFER are two BASIC programs that came with the 4041 "Accessory Kit" for programming 4041 PROMs. I can't find those programs :(
I think it would be relatively easy to make a 4041 ROM Drawer compatible circuit board that would emulate the ROM Drawer with larger EPROMs.
We just need the PRMBLD and RMXFER programs to create the 'tape' file for a PROM0.
The manual indicates on page 7-1 if the PROM0 contains an AUTOLD file, this file will automatically become the default SYSDEV device and the AUTOLD will be loaded automatically at power-up!
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10 EASY WAYS TO TROUBLESHOOT WITH AN OSCILLOSCOPE
These 10 simple exercises ¡ª beginning with the simplest and moving to the more difficult ¡ª will help sharpen your skills in the field.
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saipan59 (Pete)
Bob Headrick
Randy.AB9GO
Jared Cabot
Glydeck