Date   

Re: Newbie with a 466 that won't sweep

Harvey White
 

Deflection plate disconnected trumps bad amplifier.

Harvey

On 10/21/2021 10:56 PM, Tom Lee wrote:
I don't know if you have actually opened it up to take a look around, but if you haven't, you should check whether one of the deflection plate connections has come loose. I've encountered a handful of scopes with that problem.

--Cheers
Tom


Re: Newbie with a 466 that won't sweep

Tom Lee
 

I don't know if you have actually opened it up to take a look around, but if you haven't, you should check whether one of the deflection plate connections has come loose. I've encountered a handful of scopes with that problem.

--Cheers
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 10/20/2021 07:32, Richard Halkyard wrote:
Hi all,

I've recently become the proud owner of an early 466 (IC date codes
are all '74) that unfortunately is a bit poorly. I've done bits of
hobbyist electronics repair in the past, but I've never tackled
something quite so complicated as this before. I've been studying the
service manual and the Troubleshooting Your Oscilloscope document, but
I'd greatly appreciate any wisdom anyone would have to share.

My symptoms are:

* No horizontal sweep on any timebase setting
* X-Y mode operates as it should, but the trace is off-screen
horizontally (to the right), and can't be fully centered even with the
horizontal control all the way to the left
* Beam finder shows a bright dot on the screen, offset to the right,
but visible with the horizontal control centered
* Vertical deflection of both channels (with beam finder depressed)
looks correct in all ranges, and is more-or-less centered with the
vertical position controls at midpoint
* Depressing the Trigger View and Beam Finder buttons together shows
reasonable vertical deflection on all A trigger sources, and responds
to trigger level control.
* With a square wave input, the Triggered and/or Ready indicators
never light in any of the trigger modes (Auto, Norm, Single)
* The trigger gate outputs on the back panel are low all the time

The scope exhibited these symptoms when I first powered it on. I moved
it to my workbench and it started working for a few hours (although
with a significant horizontal offset to the trace), but after I
powered it off and put it away for the night, the problems came back
and I haven't seen a sweep since.

Power rail voltages are all within spec, although with about 20mV of
ripple, which I gather is a bit high. I haven't checked the HV and
don't have the equipment to do so safely.

Probing the pins of the sweep IC (U980) suggests that indeed, not much
is happening in sweep-land; the outputs of pins 10 (low) and 17 (2
volts) suggest that it might be stuck in holdoff, but I'm seeing DC on
the holdoff timing terminal. The IC is also noticeably hot to the
touch (although not scorching).

Additionally, the service manual suggests that the READY light
(controlled by U980 pin 11) should illuminate when the single-sweep
reset button is pressed (input on pins 2, 3), which seems to be a
fairly straightforward function of the U980's inputs and outputs.
Since this doesn't seem to happen, should I suspect U980 to be bad, or
is this likely to just be a symptom of it being stuck in holdoff for
another reason?

I realise that the sweep section isn't my only problem here, but my
rationale is that I'll have a much easier time debugging the
horizontal section if I have a working sweep, and while the power
supply ripple is out of spec, it's not drastically bad and shouldn't
be affecting the sweep section, right? If this is the wrong order in
which to tackle things, please feel free to set me straight.

Any and all help and wisdom would be appreciated, even the really
elementary stuff (I won't be offended!). I realise it's probably a bit
of an ambitious project for a newcomer, but I've always wanted a
vintage Tek scope on my workbench, and I'm quite determined to see
this through.

Thanks in advance,
Richard Halkyard




Re: Newbie with a 466 that won't sweep

Harvey White
 

The more things you have to debug at once, the more difficult it can be.  I'd go to XY mode and debug using that.  I'd hope you have a second oscilloscope, because otherwise things get difficult.

Your symptoms suggest that the horizontal amplifier has problems.  If the dot (in XY mode) cannot go to the left (or right) of the screen, then it suggests that half of the amplifier is bad.  Fortunately, the amplifier is symmetrical, so the collectors of the + part should have the same voltage

The horizontal amplifier takes a single (almost a current into a base of a transistor) input.  That is part of a differential pair that copies the signal, and also produces an out of phase signal. Those two signals drive an amplifier that has cascaded transistors to produce a + signal and a - signal, each of which drive one deflection plate.

If, for instance, the collectors of the mirror stage don't match the collectors of the other stage (one stage each deflection plate), then start looking there.

Harvey

On 10/20/2021 10:32 AM, Richard Halkyard wrote:
Hi all,

I've recently become the proud owner of an early 466 (IC date codes
are all '74) that unfortunately is a bit poorly. I've done bits of
hobbyist electronics repair in the past, but I've never tackled
something quite so complicated as this before. I've been studying the
service manual and the Troubleshooting Your Oscilloscope document, but
I'd greatly appreciate any wisdom anyone would have to share.

My symptoms are:

* No horizontal sweep on any timebase setting
* X-Y mode operates as it should, but the trace is off-screen
horizontally (to the right), and can't be fully centered even with the
horizontal control all the way to the left
* Beam finder shows a bright dot on the screen, offset to the right,
but visible with the horizontal control centered
* Vertical deflection of both channels (with beam finder depressed)
looks correct in all ranges, and is more-or-less centered with the
vertical position controls at midpoint
* Depressing the Trigger View and Beam Finder buttons together shows
reasonable vertical deflection on all A trigger sources, and responds
to trigger level control.
* With a square wave input, the Triggered and/or Ready indicators
never light in any of the trigger modes (Auto, Norm, Single)
* The trigger gate outputs on the back panel are low all the time

The scope exhibited these symptoms when I first powered it on. I moved
it to my workbench and it started working for a few hours (although
with a significant horizontal offset to the trace), but after I
powered it off and put it away for the night, the problems came back
and I haven't seen a sweep since.

Power rail voltages are all within spec, although with about 20mV of
ripple, which I gather is a bit high. I haven't checked the HV and
don't have the equipment to do so safely.

Probing the pins of the sweep IC (U980) suggests that indeed, not much
is happening in sweep-land; the outputs of pins 10 (low) and 17 (2
volts) suggest that it might be stuck in holdoff, but I'm seeing DC on
the holdoff timing terminal. The IC is also noticeably hot to the
touch (although not scorching).

Additionally, the service manual suggests that the READY light
(controlled by U980 pin 11) should illuminate when the single-sweep
reset button is pressed (input on pins 2, 3), which seems to be a
fairly straightforward function of the U980's inputs and outputs.
Since this doesn't seem to happen, should I suspect U980 to be bad, or
is this likely to just be a symptom of it being stuck in holdoff for
another reason?

I realise that the sweep section isn't my only problem here, but my
rationale is that I'll have a much easier time debugging the
horizontal section if I have a working sweep, and while the power
supply ripple is out of spec, it's not drastically bad and shouldn't
be affecting the sweep section, right? If this is the wrong order in
which to tackle things, please feel free to set me straight.

Any and all help and wisdom would be appreciated, even the really
elementary stuff (I won't be offended!). I realise it's probably a bit
of an ambitious project for a newcomer, but I've always wanted a
vintage Tek scope on my workbench, and I'm quite determined to see
this through.

Thanks in advance,
Richard Halkyard





Re: tek 2215 trace position issues

Mark Vincent
 

Replace the four resistors you asked about with https://www.mouser.com/ProductDetail/Vishay-Dale/CCF60340RFKE36?qs=%2Fha2pyFaduhwK32S4jrtN7H6uGCoKCRsNsGmRuIvfhY%3D. Mount these resistors off the boards a few mm to allow air flow. The 51 ohm types can be https://www.mouser.com/c/passive-components/resistors/film-resistors/metal-film-resistors-through-hole/?q=1%25%20resistor&power%20rating=500%20mW%20%281%2F2%20W%29&resistance=51%20Ohms&instock=y. Ordering 100 of the Xicon will give you enough stock for a while.

Replace the RIFAs off the mains input! These will be a clear amber colour. These are an X2 type. Get the ones with the highest voltage you can, 300VAC or higher. These RIFAs WILL fail. You will know it when they do!

Mark


Re: Idle Question About the 485

Brad Thompson
 

Dave Daniel wrote on 10/21/2021 6:02 PM:

Mark, that is excellent advice. Unfortunately, it doesn’t work when it comes to Tektronix oscilloscopes.

DaveD

On Oct 21, 2021, at 17:56, Mark Vincent <orangeglowaudio@gmail.com> wrote:

Jeff,

You want the scope, not need it.
<snip>

Hello--

...From Bob Dylan's "Stuck Inside  Of Mobile With The Memphis  Blues Again":

...And I say, "Aw, come on now
You know you know about my debutante"
And she says, "Your debutante just knows what you need <https://genius.com/10171338/Bob-dylan-stuck-inside-of-mobile-with-the-memphis-blues-again/Your-debutante-just-knows-what-you-need-but-i-know-what-you-want>
But I know what you want" <https://genius.com/10171338/Bob-dylan-stuck-inside-of-mobile-with-the-memphis-blues-again/Your-debutante-just-knows-what-you-need-but-i-know-what-you-want>

73--

Brad  AA1IP


Re: Newbie with a 466 that won't sweep

Mark Vincent
 

Richard,

Try cleaning the switches including the time base contacts. Dirty switches can cause a lot of problems. Cleaning IC and transistor sockets may also or should be done.

The power supply should have new electrolytics in it that are high temperature, low ESR and long life types. Increasing the capacitance is fine. See if VR1726 is open (very likely). If so, use BZX85B9V1. The output filters from the series pass can be raised in value. The 3.6mfd on the 65V supply should be 10mfd or larger 100V (Nichicon UHE type). Using something like 27mfd 100V at the 65V filter is fine, this is an example that will work. Nichicon ULD is what I used in the lower voltage areas. A 47mfd 25V on the other 5-15V supplies works fine. C1455, 10mfd, check/replace if electrolytic with a new one. The rest of the tantalums can be checked for shorts or high ESR and replaced if bad. Good ones, leave them in. There are resistors that should be raised in wattage throughout the scope. R1445 and R1547 are likely high (out of tolerance). The 1.5A bridge rectifiers should be replaced with 4A types. Using a higher voltage rating than the original 200V is fine. The current increase is the main concern.

I have this model and have overhauled it. Do the cleaning first then test. Adjusting the Mag Reg. pot may need to be centered to get the trace centered. I did add heatsinks to the horiz. outputs.

Mark


tek 2215 trace position issues

nanovnauser@...
 

hi all i have a sick tek 2215 scope,the issue is the trace is too low on the screen( both channels affected ),i can only position the trace about halfway up the screen using the position controlls,i have checked the r378 r379 r389 and r 388,they are as follows 378=314 ohms 379= 309 ohms 389= 321 ohms and 388= 316 ohms,the two resistors on the deflection plate wires are 57 ohms not 51 as per manual,any ideas of whats wrong,im sort of stuck,also q387 and q386 test ok.,thanks in advance .


Newbie with a 466 that won't sweep

Richard Halkyard
 

Hi all,

I've recently become the proud owner of an early 466 (IC date codes
are all '74) that unfortunately is a bit poorly. I've done bits of
hobbyist electronics repair in the past, but I've never tackled
something quite so complicated as this before. I've been studying the
service manual and the Troubleshooting Your Oscilloscope document, but
I'd greatly appreciate any wisdom anyone would have to share.

My symptoms are:

* No horizontal sweep on any timebase setting
* X-Y mode operates as it should, but the trace is off-screen
horizontally (to the right), and can't be fully centered even with the
horizontal control all the way to the left
* Beam finder shows a bright dot on the screen, offset to the right,
but visible with the horizontal control centered
* Vertical deflection of both channels (with beam finder depressed)
looks correct in all ranges, and is more-or-less centered with the
vertical position controls at midpoint
* Depressing the Trigger View and Beam Finder buttons together shows
reasonable vertical deflection on all A trigger sources, and responds
to trigger level control.
* With a square wave input, the Triggered and/or Ready indicators
never light in any of the trigger modes (Auto, Norm, Single)
* The trigger gate outputs on the back panel are low all the time

The scope exhibited these symptoms when I first powered it on. I moved
it to my workbench and it started working for a few hours (although
with a significant horizontal offset to the trace), but after I
powered it off and put it away for the night, the problems came back
and I haven't seen a sweep since.

Power rail voltages are all within spec, although with about 20mV of
ripple, which I gather is a bit high. I haven't checked the HV and
don't have the equipment to do so safely.

Probing the pins of the sweep IC (U980) suggests that indeed, not much
is happening in sweep-land; the outputs of pins 10 (low) and 17 (2
volts) suggest that it might be stuck in holdoff, but I'm seeing DC on
the holdoff timing terminal. The IC is also noticeably hot to the
touch (although not scorching).

Additionally, the service manual suggests that the READY light
(controlled by U980 pin 11) should illuminate when the single-sweep
reset button is pressed (input on pins 2, 3), which seems to be a
fairly straightforward function of the U980's inputs and outputs.
Since this doesn't seem to happen, should I suspect U980 to be bad, or
is this likely to just be a symptom of it being stuck in holdoff for
another reason?

I realise that the sweep section isn't my only problem here, but my
rationale is that I'll have a much easier time debugging the
horizontal section if I have a working sweep, and while the power
supply ripple is out of spec, it's not drastically bad and shouldn't
be affecting the sweep section, right? If this is the wrong order in
which to tackle things, please feel free to set me straight.

Any and all help and wisdom would be appreciated, even the really
elementary stuff (I won't be offended!). I realise it's probably a bit
of an ambitious project for a newcomer, but I've always wanted a
vintage Tek scope on my workbench, and I'm quite determined to see
this through.

Thanks in advance,
Richard Halkyard


Re: Idle Question About the 485

Paul
 

Yeah, but when you reach 81 years old, like me, it's all wants from now on
out <grin>.

Paul

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Mark
Vincent
Sent: Thursday, October 21, 2021 2:57 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Idle Question About the 485

Jeff,

You want the scope, not need it. That is enough to hold onto the money. I
have done this and was glad I did. I soon needed the money for something
that was a necessity/emergency. Had I spent the money initially, I would
have been screwed when I needed it. There is a huge difference between want
and need, although many do not believe this.

Mark



--
This email has been checked for viruses by AVG.
https://www.avg.com


Re: Idle Question About the 485

Dave Peterson
 

I had to go back and look at my sent folder.

Either Jeff is pulling my leg, or someone misquoted me. I was apologizing for crashing (as in party crashing) the thread with a query about the Dual BNC connector that I _should_ be spending my money on. Not declaring the thread in a state of distress.

I was ogling this auction: https://www.ebay.com/itm/393629455921?mkpid=2&emsid=e90001.m43.l1123&mkcid=8&bu=45266711467&osub=da6190742e21c88966a5bd602a151423%257ETE80101_T_AGM&segname=TE80101_T_AGM&crd=20211021100500&ch=osgood&trkId=0AD3955E-9CB5EF4BE09-017C9CFA43F0-00000000005C52FB&mesgId=3016&plmtId=700001&recoId=393629455921&recoPos=1&sojTags=osub%3Dosub%2Csegname%3Dsegname%2Ccrd%3Dcrd%2Cch%3Dch%2CtrkId%3DtrkId%2CmesgId%3DmesgId%2CplmtId%3DplmtId%2CrecoId%3DrecoId%2CrecoPos%3DrecoPos%2Cchnl%3Dmkcid&autorefresh=true&nma=true&si=fGK89AySDjsw3kBXQ1g%252BasakP1Y%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

For that money I can buy a lot of what I need. But it does include a couple/few things I want.

On Thursday, October 21, 2021, 05:55:36 PM PDT, Jeff Dutky <jeff.dutky@gmail.com> wrote:

Dave Peterson wrote:

sorry this thread is crashing
As the OP I don’t think that the thread is crashing at all, the question about the 485 trigger view feature was only half of the original question. Avoiding bidding on auctions was at least as important.

I feel bad when I see a nice item with a low starting bid and nobody bidding. I always imagine that it’s an individual just trying to sell the item, may it had sentimental value, or maybe they need the money so badly that they’re parting with it, and I just feel bad. Of course sometimes I bid because the starting bid is ridiculously low, and I’d be a fool to pass it up for that price. Other times it’s because the item is something that imagine might go to the dump and be picked over by tube thieves if it doesn’t sell.

None of that obtains here. I’ve got so empathy for surplus businesses, and the price is not low enough to be impossible to refuse. I’m still willing to have a bull session over the particulars of our shared addiction.

— Jeff Dutky


Re: Idle Question About the 485

 

Dave Peterson wrote:

sorry this thread is crashing
As the OP I don’t think that the thread is crashing at all, the question about the 485 trigger view feature was only half of the original question. Avoiding bidding on auctions was at least as important.

I feel bad when I see a nice item with a low starting bid and nobody bidding. I always imagine that it’s an individual just trying to sell the item, may it had sentimental value, or maybe they need the money so badly that they’re parting with it, and I just feel bad. Of course sometimes I bid because the starting bid is ridiculously low, and I’d be a fool to pass it up for that price. Other times it’s because the item is something that imagine might go to the dump and be picked over by tube thieves if it doesn’t sell.

None of that obtains here. I’ve got so empathy for surplus businesses, and the price is not low enough to be impossible to refuse. I’m still willing to have a bull session over the particulars of our shared addiction.

— Jeff Dutky


Re: FS: 7000 series (parts) plugins 7A18 (X2) 7B53A and 067-0657 Calibration Fixture

Mark Vincent
 

I see a 7D14 in a photo. If that is for sale, let me know the price.

Mark


Re: “Collecting” Tektronix ‘scopes

stevenhorii
 

Dave,

I can actually use the J20/7J20 set. I do some calibration work on medical
monitors (I am a radiologist) more for research as we have QA folks who do
it for all the installed workstation monitors. I am interested in more
parameters than what they need for QA though.

Contact me off list if you still have the pair and would be interested in
selling or swapping it.

Steve Horii
sonodocsch@gmail.com

On Thu, Oct 21, 2021 at 18:57 Dave Daniel <kc0wjn@gmail.com> wrote:

Starting a new thread on this here.

Yes, it is insidious. I’m not sure why, except that the excellence of the
‘scopes is attractive, and after the first repair of one of these using the
Tektronix service manual (which amount to courses in analog engineering),
one seems to become enamored with the wide variety of Tektronix ‘scopes.

As I wrote earlier, my first acquistions were a 7904A and a 485. Actually,
I had purchased a 465 many years earlier. I later became convinced that it
had been stolen from Documation, the company for which I worked and which
was acquired by StorageTek.

Later, I acquired a second 485 as a spare. Then I found a non-working 7104
for about $200. It still needs work. At that point I started looking for
specific ‘scopes. A 7934 was my next find; I bought it for about $150; it
was sold “for parts only”. It turned out the the PO had put a 2A fuse in it
when a 4A fuse was required. It’s worked flawlessly ever since.

An SC-502 was acquired after I bought a TM-5006. I bought a second
inexpensive and non-working SC-502 as a parts mule soon after.

The other targeted ‘scopes were a 310A, a 547 (a la Jim Williams) and a
2465BDV, which I acquired at reasonable prices through much patience.

The 310A that I found came with a leather carrying case specific to IBM.
The 2465BDV was another good deal found through severe patience.

There was a guy in Denver that had a 547 on Craigslist for $20; I
immediately went down there to buy it only to discover that it didn’t work.
The owner gave it to me; it came with a Scopemobile.

There was a surplus electronics store in Boulder, CO that went out of
business. Shortly after that happened, I stopped by on a Saturday to find a
7623A on the picnic table with a “free” sign on it, so I took it.

A couple of years I found a J20/7J20 spectrometer on ebay, which I bought.
It came with a 3 slot mainframe (7314?) for which I have no use and would
give away to anyone who wanted to come and pick it up.

A few months ago a friend gave me a 475, which I plan to repair and give
to the luthier who maintains mg Gibson guitars.

————————————————————-
DaveD, that is so true!

I'm entertaining myself watching another item by the same seller that is
about to expire. It pushes a lot of "want" buttons, but for the cost I can
easily buy several items that I could really use. I'm fascinated by my own
irrational urge to bid. This auction thing is diabolical.

Speaking of need: anyone have a line on a 067-0525-01 or 02?

I have a current work around with fairly well matched 3' cables. But I'd
really rather have the right thing.

Sorry for the thread crashing.
Dave


On Thursday, October 21, 2021, 03:04:27 PM PDT, Dave Daniel <
kc0wjn@gmail.com> wrote:

Mark, that is excellent advice. Unfortunately, it doesn’t work when it
comes to Tektronix oscilloscopes.

DaveD






Re: “Collecting” Tektronix ‘scopes

stevenhorii
 

On Thu, Oct 21, 2021 at 18:57 Dave Daniel <kc0wjn@gmail.com> wrote:

Starting a new thread on this here.

Yes, it is insidious. I’m not sure why, except that the excellence of the
‘scopes is attractive, and after the first repair of one of these using the
Tektronix service manual (which amount to courses in analog engineering),
one seems to become enamored with the wide variety of Tektronix ‘scopes.

As I wrote earlier, my first acquistions were a 7904A and a 485. Actually,
I had purchased a 465 many years earlier. I later became convinced that it
had been stolen from Documation, the company for which I worked and which
was acquired by StorageTek.

Later, I acquired a second 485 as a spare. Then I found a non-working 7104
for about $200. It still needs work. At that point I started looking for
specific ‘scopes. A 7934 was my next find; I bought it for about $150; it
was sold “for parts only”. It turned out the the PO had put a 2A fuse in it
when a 4A fuse was required. It’s worked flawlessly ever since.

An SC-502 was acquired after I bought a TM-5006. I bought a second
inexpensive and non-working SC-502 as a parts mule soon after.

The other targeted ‘scopes were a 310A, a 547 (a la Jim Williams) and a
2465BDV, which I acquired at reasonable prices through much patience.

The 310A that I found came with a leather carrying case specific to IBM.
The 2465BDV was another good deal found through severe patience.

There was a guy in Denver that had a 547 on Craigslist for $20; I
immediately went down there to buy it only to discover that it didn’t work.
The owner gave it to me; it came with a Scopemobile.

There was a surplus electronics store in Boulder, CO that went out of
business. Shortly after that happened, I stopped by on a Saturday to find a
7623A on the picnic table with a “free” sign on it, so I took it.

A couple of years I found a J20/7J20 spectrometer on ebay, which I bought.
It came with a 3 slot mainframe (7314?) for which I have no use and would
give away to anyone who wanted to come and pick it up.

A few months ago a friend gave me a 475, which I plan to repair and give
to the luthier who maintains mg Gibson guitars.

————————————————————-
DaveD, that is so true!

I'm entertaining myself watching another item by the same seller that is
about to expire. It pushes a lot of "want" buttons, but for the cost I can
easily buy several items that I could really use. I'm fascinated by my own
irrational urge to bid. This auction thing is diabolical.

Speaking of need: anyone have a line on a 067-0525-01 or 02?

I have a current work around with fairly well matched 3' cables. But I'd
really rather have the right thing.

Sorry for the thread crashing.
Dave


On Thursday, October 21, 2021, 03:04:27 PM PDT, Dave Daniel <
kc0wjn@gmail.com> wrote:

Mark, that is excellent advice. Unfortunately, it doesn’t work when it
comes to Tektronix oscilloscopes.

DaveD






Re: FS: 7000 series (parts) plugins 7A18 (X2) 7B53A and 067-0657 Calibration Fixture

Leon Robinson
 

I am looking for the connector in the 7A11 that the probe plugs
into,or the connector and the plastic housing that is partially
shown in the photo.
Leon Robinson    K5JLR

Political Correctness is a Political Disease.

Politicians and Diapers should be changed
often and for the same reasons.

On Thursday, October 21, 2021, 6:22:13 PM CDT, Oz-in-DFW <lists@ozindfw.net> wrote:

There are two 7A18s in differing condition, pics here::

https://ozindfw.net/7A18a/ $10
https://ozindfw.net/7A18b/ $15

The 7B53A is really rough, $5 and pics are here:

https://ozindfw.net/7B53A/

067-0657 Calibration Fixture is pristine, $15 pics here:

https://ozindfw.net/CalFixt/

History indicates that a single plugin will cost on the order of $20 to ship inside the US.  I ship at cost.  I'll get an estimate for a shipment boxed and ready to go.  I don't charge for shipping material unless I have to buy something, and that's pretty rare. The incremental cost of additional plugins is usually small.

While I'm happy to ship outside the US, the cost is usually not very attractive. 

--
Oz (in DFW, Texas USA) N1OZ


Re: FS: 7000 series (parts) plugins 7A18 (X2) 7B53A and 067-0657 Calibration Fixture

Zentronics42@...
 

Oz,
I would be interested in the 067-0657 if it is not spoken for yet.

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Oz-in-DFW
Sent: Thursday, October 21, 2021 7:22 PM
To: TekScopes@groups.io
Subject: [TekScopes] FS: 7000 series (parts) plugins 7A18 (X2) 7B53A and 067-0657 Calibration Fixture

There are two 7A18s in differing condition, pics here::

https://ozindfw.net/7A18a/ $10
https://ozindfw.net/7A18b/ $15

The 7B53A is really rough, $5 and pics are here:

https://ozindfw.net/7B53A/

067-0657 Calibration Fixture is pristine, $15 pics here:

https://ozindfw.net/CalFixt/

History indicates that a single plugin will cost on the order of $20 to ship inside the US. I ship at cost. I'll get an estimate for a shipment boxed and ready to go. I don't charge for shipping material unless I have to buy something, and that's pretty rare. The incremental cost of additional plugins is usually small.

While I'm happy to ship outside the US, the cost is usually not very attractive.

--
Oz (in DFW, Texas USA) N1OZ


FS: 7000 series (parts) plugins 7A18 (X2) 7B53A and 067-0657 Calibration Fixture

Oz-in-DFW
 

There are two 7A18s in differing condition, pics here::

https://ozindfw.net/7A18a/ $10
https://ozindfw.net/7A18b/ $15

The 7B53A is really rough, $5 and pics are here:

https://ozindfw.net/7B53A/

067-0657 Calibration Fixture is pristine, $15 pics here:

https://ozindfw.net/CalFixt/

History indicates that a single plugin will cost on the order of $20 to ship inside the US. I ship at cost. I'll get an estimate for a shipment boxed and ready to go. I don't charge for shipping material unless I have to buy something, and that's pretty rare. The incremental cost of additional plugins is usually small.

While I'm happy to ship outside the US, the cost is usually not very attractive.

--
Oz (in DFW, Texas USA) N1OZ


“Collecting” Tektronix ‘scopes

Dave Daniel
 

Starting a new thread on this here.

Yes, it is insidious. I’m not sure why, except that the excellence of the ‘scopes is attractive, and after the first repair of one of these using the Tektronix service manual (which amount to courses in analog engineering), one seems to become enamored with the wide variety of Tektronix ‘scopes.

As I wrote earlier, my first acquistions were a 7904A and a 485. Actually, I had purchased a 465 many years earlier. I later became convinced that it had been stolen from Documation, the company for which I worked and which was acquired by StorageTek.

Later, I acquired a second 485 as a spare. Then I found a non-working 7104 for about $200. It still needs work. At that point I started looking for specific ‘scopes. A 7934 was my next find; I bought it for about $150; it was sold “for parts only”. It turned out the the PO had put a 2A fuse in it when a 4A fuse was required. It’s worked flawlessly ever since.

An SC-502 was acquired after I bought a TM-5006. I bought a second inexpensive and non-working SC-502 as a parts mule soon after.

The other targeted ‘scopes were a 310A, a 547 (a la Jim Williams) and a 2465BDV, which I acquired at reasonable prices through much patience.

The 310A that I found came with a leather carrying case specific to IBM. The 2465BDV was another good deal found through severe patience.

There was a guy in Denver that had a 547 on Craigslist for $20; I immediately went down there to buy it only to discover that it didn’t work. The owner gave it to me; it came with a Scopemobile.

There was a surplus electronics store in Boulder, CO that went out of business. Shortly after that happened, I stopped by on a Saturday to find a 7623A on the picnic table with a “free” sign on it, so I took it.

A couple of years I found a J20/7J20 spectrometer on ebay, which I bought. It came with a 3 slot mainframe (7314?) for which I have no use and would give away to anyone who wanted to come and pick it up.

A few months ago a friend gave me a 475, which I plan to repair and give to the luthier who maintains mg Gibson guitars.

————————————————————-
DaveD, that is so true!

I'm entertaining myself watching another item by the same seller that is about to expire. It pushes a lot of "want" buttons, but for the cost I can easily buy several items that I could really use. I'm fascinated by my own irrational urge to bid. This auction thing is diabolical.

Speaking of need: anyone have a line on a 067-0525-01 or 02?

I have a current work around with fairly well matched 3' cables. But I'd really rather have the right thing.

Sorry for the thread crashing.
Dave

On Thursday, October 21, 2021, 03:04:27 PM PDT, Dave Daniel <kc0wjn@gmail.com> wrote:

Mark, that is excellent advice. Unfortunately, it doesn’t work when it comes to Tektronix oscilloscopes.

DaveD


Re: TEK 475: Dead on Start Up.

Mlynch001
 

I believe that you would be better off changing to a modern and higher voltage rated tantalum cap rather than substituting in a potentially inferior performing aluminum electrolytic cap. This will keep the circuits closer to the original design, but the higher voltage rated caps should give more margin of safety. My 2 cents and how I repair the scopes that come across the bench.

--
Michael Lynch
Dardanelle, AR


Re: Idle Question About the 485

Dave Peterson
 

DaveD, that is so true!

I'm entertaining myself watching another item by the same seller that is about to expire. It pushes a lot of "want" buttons, but for the cost I can easily buy several items that I could really use. I'm fascinated by my own irrational urge to bid. This auction thing is diabolical.

Speaking of need: anyone have a line on a 067-0525-01 or 02?

I have a current work around with fairly well matched 3' cables. But I'd really rather have the right thing.

Sorry for the thread crashing.
Dave

On Thursday, October 21, 2021, 03:04:27 PM PDT, Dave Daniel <kc0wjn@gmail.com> wrote:

Mark, that is excellent advice. Unfortunately, it doesn’t work when it comes to Tektronix oscilloscopes.

DaveD

On Oct 21, 2021, at 17:56, Mark Vincent <orangeglowaudio@gmail.com> wrote:

Jeff,

You want the scope, not need it. That is enough to hold onto the money. I have done this and was glad I did. I soon needed the money for something that was a necessity/emergency. Had I spent the money initially, I would have been screwed when I needed it. There is a huge difference between want and need, although many do not believe this.

Mark




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