Date   

Re: Very Inexpensive 7623A, but Problems

Eric
 

Take LOTS of pictures. The harmonica connectors have many different voltages on them as low as 5.5 to as high as 130. I quicky turned a 7603 in to a parts unit one when I switched 2 of them. Sent 130Vdc to all the wrong places. Ended up with too much damage to save it so now I at least have a spare CRT.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Jeff Dutky
Sent: Saturday, February 13, 2021 6:34 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Very Inexpensive 7623A, but Problems

I came across this video (https://youtu.be/H-9YdqiptDM?t=1013) and it shows something that looks very much like what I am seeing. The caption, just before it shows the radiating twisting traces says "This is how it looks with the defective capacitor inside..."

This fills me with hope.

-- Jeff Dutky


Re: EIP 101B Spectrum Analyzer Plug-In on E-bay

Alain Mionnet
 

Chris,

Thank you very much for your manual. The good time where all was included in it !
Could be helpfull if the hardware debug is needed.
Yesterday evening I have opened a photos album for EIP101A, for the moment only 1 picture.(front panel)
Then I didn't made an announcement ! see https://groups.io/g/TekScopes/album?id=260634
I have others not very professional. May be I will have better soon.
Note that frame box associated is 201B.

Note also that for a short time EIP had been buyed par DANA LABS Irvine.(Centered on digital voltmeters, measurement amplifiers, frequency counters under 520 MHz) Around 1973/74 ?, from DANA they have pick the case, but the handles have been re-inforced.

Alain

France


Re: Waking a slumbering 475

Michael A. Terrell
 

Jeff Dutky wrote:
Michael,

I had not tried Google Groups directly; I just assumed that that was something a general Google search would hit.

Searching in Google Groups directly does, indeed, turn up the original conversation. Here is the conversation that I, fool that I am, took at face value:

Jeffrey S. Dutky (May 9, 2003, 1:26:17 AM)
I have two old osiloscopes, a Tek 2213 and a Tek 475, that have been in
storage for the last five years under less than ideal conditions (in my
parent's basement, cool and humid).

Does anyone have any advice on what I can do to get these things ready
for use again? The only thing I can think of is to bake them at low
temperature in an attempt to expell any moisture that has collected in
the components, but I'm not sure what a safe temperature range would be.
I don't want to simply power them up without making some attempt to
determine if they'll go POP! or not, and maybe do something to prevent it.
Grump OM (May 9, 2003, 7:44:19 AM)
Take off the side panels and clean out dust with a 1 inch paint
brush and low pressure air. Look for chassis rust or corrosion that
would indicate moisture. Go over it with a hair dryer being careful
not to overheat components. Use a variac and bring up voltage slowly
to let electrolytic caps reform. Watch for smoke.

Grumpy
Two things stand out to me now: 1. the talk of "reforming" caps should have been a red flag, 2. Grumpy OM clearly thought I was talking about a tube scope ("take off the side panels").

Someone by the name of Jim Yanik did try to warn me about using the variac on the 2213, but he was not nearly explicit enough in his warning.

In the end I don't think that any damage was done to either the 475 or (surprisingly) the 2213 by "slow starting" them on the variac. It did let me see that the 475's LOW LINE indicator worked (that's in my notes, though I thought it was a power indicator at first), and it was basically inert until I got up to 70VAC, then the LOW LINE lamp and CRT came up. The 2213 did something a little more frightening, emitting a high pitched squeel at around 60VAC, but it came ready at 80VAC. I'm glad I didn't kill it by accident.
news:sci.elctronics was replaced by the various subgroups by the Time I went online in the late '90s, and not carried on the Usenet servers that I had access to. I only saw it when it was crossposted to another group, and had to delete it to reply.

You should have listened to Jim. He worked at the Orlando Tektronix until it closed. He knew many models inside and out, since he repaired them 40+ hours a week. He disappeared from Usenet a while back, and his phone number no longer worked so I suspect that he's passed away.

Rule of thumb, read the specified input voltage range and keep a Variac in that range. Also, some early 120/240 switchless supplies couldn't tolerate being in between the high end of 120 and the low end of the 240 volt ranges.


Re: Very Inexpensive 7623A, but Problems

 

I came across this video (https://youtu.be/H-9YdqiptDM?t=1013) and it shows something that looks very much like what I am seeing. The caption, just before it shows the radiating twisting traces says "This is how it looks with the defective capacitor inside..."

This fills me with hope.

-- Jeff Dutky


Re: Very Inexpensive 7623A, but Problems

 

Jean-Paul,

I've had a little fun swapping the plug-ins around, but it hasn't made much difference in the display (it's made some difference, but I'm still not getting anything like real horizontal or vertical deflection). The twisted radiating lines are a constant feature, no matter which slots which plug-ins are in, or even if there are no plug-ins installed. Those lines only respond to the readout intensity control, the main intensity control seems to have not effect at all.

David,

Thanks for chiming in; every reassurance that I don't have a busted CRT raises my spirits. I was really excited to have an analog storage scope to play with, and I had been holding off because I was scared that either a lot of scopes I saw on the auction site seemed to have malfunctioning CRTs (or the people taking the pictures had no idea how to set the intensity properly), or that a good CRT would arrive demolished in transport (that happened to one scope, already).

I'm going to do a full visual inspection of the mainframe, and then check all the power rails, but not tonight. I need all my wits about me for an operation like that.

-- Jeff Dutky


Re: Very Inexpensive 7623A, but Problems

 

The readout looks correct, so I think the CRT is probably OK.

D.

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Jeff Dutky
Sent: 13 February 2021 06:14
To: TekScopes@groups.io
Subject: [TekScopes] Very Inexpensive 7623A, but Problems


am I looking at a CRT replacement?


Re: Hey this isn't even on Tekwiki!

 

If goods not as described eBay rules say Seller pays return postage

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of John Williams
Sent: 12 February 2021 21:30
To: TekScopes@groups.io
Subject: Re: [TekScopes] Hey this isn't even on Tekwiki!

all the seller has to say to the buyer is “Return the item for a full refund.” When the postage to return it is more than the refund, then the seller wins.


Re: Very Inexpensive 7623A, but Problems

Jean-Paul
 

Jeff definitely check PSU and HVPS/CRT voltages first, also check for loose or disconnected CRT deflection leads.

You can run these with Vert modules in the Hor socket, for testing.

With no plugin in the H position you will get a vertical line and visa versa.

With no plugins at all just a single spot, centered and undeflected (keep intensity low)

Kind Regards,

Jon


Re: Very Inexpensive 7623A, but Problems

 

Tom,

Extra fun indeed.

Yes, the readouts do appear to reflect the control settings. Parts of the readouts come and go in unpredictable ways, however, and this intermittence is affected by vigorously wiggling the main knobs on the plugins, but not apparently by tapping or knocking on the case, which I take to imply that the malfunction is not due to something loose in the CRT, but may be confined to the plugins. (EDIT: it's NOT confined to the plugins, the radiating twisted traces are still there with all plug-ins removed)

Stephen,

Yes, the timebase has been sorely abused and the main knob is bent out at about a 15 degree angle. I am able to take the timebase into and out of mixed mode, but I fear that there is some internal damage from the force that bent the knob. It looks like the outer shaft that is engaged by the large knob, has sheered off, and the outer knob is jammed in a position that prevents me from removing the cal knob.

I have ordered an entire new timebase plug-in, but it will be a week or so before it arrives. I'm just assuming that the timebase is borked, and a replacement was pretty inexpensive.

I tried powering the mainframe without the plug-ins, and I still have the twisted radiating lines. Only the readout intensity knob has any effect on the display. I tried working the storage controls but couldn't get anything recognizable to happen.

I guess I should begin at the beginning: take off the sides of the case, do a full visual inspection, and then check the power supply levels. That's probably the best I can do until the new horizontal plug-in arrives.

-- Jeff Dutky


Re: Spectrum analyzer Tektronix 7L13 on mainframe Tektronix 7603

Attilio
 

Thanks Ed,
I did not think about it. I'll read the instructions in the 7L13 manual.

--Cheers
Attilio


Re: Very Inexpensive 7623A, but Problems

Stephen Bell
 

The CRT can't be all that bad given that the readout is displaying recognizable albeit blurry characters.

Can you improve the focus of the characters? Try turning the brightness down a little to see if that improves the focus.

The traces of the calibrator waveform would seem to indicate a problem with the timebase module. The time/div knob looks bent and it could be stuck in the mixed timebase mode which might give the display you are seeing.Try pushing the time/div knob into disengage mixed mode sweep.

Do you have another timebase plug-in you could substitute to verify whether the timebase module is faulty?


File /EIP 101A_201A Ops_Svc OCR.pdf uploaded #file-notice

TekScopes@groups.io Notification <noreply@...>
 

The following files have been uploaded to the Files area of the TekScopes@groups.io group.

By: ChrisBeee <chrisbeee@...>

Description:
searchable Operating and Service manual for EIP 101A Spectrum Analyzer and EIP 201A Power Supply


Re: EIP 101B Spectrum Analyzer Plug-In on E-bay

ChrisBeee
 

Hi Daniel, hi Dennis,
it looks like I have a treasure in my library: an EIP 101A/201A Ops/Svc manual for my 101A s/n34. I have scanned and uploaded it to the Files section. Later in the day, I will take some beauty shots of my unit and upload both to TekWiki also.
Chris


Re: Stan Griffiths estate sale

Tam Hanna
 

Hello,

this is exactly what I want to avoid, I am already flooded with crap email.


I was hoping one of you has the email address...


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: Waking a slumbering 475

 

Michael,

I had not tried Google Groups directly; I just assumed that that was something a general Google search would hit.

Searching in Google Groups directly does, indeed, turn up the original conversation. Here is the conversation that I, fool that I am, took at face value:

Jeffrey S. Dutky (May 9, 2003, 1:26:17 AM)

I have two old osiloscopes, a Tek 2213 and a Tek 475, that have been in
storage for the last five years under less than ideal conditions (in my
parent's basement, cool and humid).

Does anyone have any advice on what I can do to get these things ready
for use again? The only thing I can think of is to bake them at low
temperature in an attempt to expell any moisture that has collected in
the components, but I'm not sure what a safe temperature range would be.
I don't want to simply power them up without making some attempt to
determine if they'll go POP! or not, and maybe do something to prevent it.
Grump OM (May 9, 2003, 7:44:19 AM)

Take off the side panels and clean out dust with a 1 inch paint
brush and low pressure air. Look for chassis rust or corrosion that
would indicate moisture. Go over it with a hair dryer being careful
not to overheat components. Use a variac and bring up voltage slowly
to let electrolytic caps reform. Watch for smoke.

Grumpy
Two things stand out to me now: 1. the talk of "reforming" caps should have been a red flag, 2. Grumpy OM clearly thought I was talking about a tube scope ("take off the side panels").

Someone by the name of Jim Yanik did try to warn me about using the variac on the 2213, but he was not nearly explicit enough in his warning.

In the end I don't think that any damage was done to either the 475 or (surprisingly) the 2213 by "slow starting" them on the variac. It did let me see that the 475's LOW LINE indicator worked (that's in my notes, though I thought it was a power indicator at first), and it was basically inert until I got up to 70VAC, then the LOW LINE lamp and CRT came up. The 2213 did something a little more frightening, emitting a high pitched squeel at around 60VAC, but it came ready at 80VAC. I'm glad I didn't kill it by accident.

-- Jeff Dutky


Re: Very Inexpensive 7623A, but Problems

Tom Lee
 

Ok, so you have several possible points of failure, then. That makes troubleshooting extra fun.

Out of curiosity, does the readout properly reflect the states of the corresponding plug-ins' settings?

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

On 2/12/2021 22:50, Jeff Dutky wrote:
The plug-ins came with the unit, and they all have some damage, especially the horizontal plug-in, whose TIME/DIV knob is badly bent (is that visible in the picture?). So, no, the plugins are NOT "known good".

This scope comprises the entirety of my 7000-series collection.

Also, I was wrong about the traces not responding to controls: I can get those wiggly radial traces to shimmy a little bit by adjusting the horizontal position knob.

The plug-ins, aside from the knob damage, appeared good to a cursory inspection (I gave the scope a once over before I plugged her in. I'm fool hardy, but I'm not completely reckless).

I would be very happy if the problem were just the plug-ins.

I'm waiting on the replacement fuse and capacitor (though, I guess they're not strictly necessary).

I tried connecting a probe and seeing if I could get any kind of trace from the calibration signals, but got nothing. Then I put the probe back on the scope it came from, and checked the 7623A's calibration signals and they look kind of wonky: the 2236 couldn't get a stable trace on them (I'll put pictures in the album).

Clearly this is a sick little scope. What fun!

-- Jeff Dutky




Re: Very Inexpensive 7623A, but Problems

 

The plug-ins came with the unit, and they all have some damage, especially the horizontal plug-in, whose TIME/DIV knob is badly bent (is that visible in the picture?). So, no, the plugins are NOT "known good".

This scope comprises the entirety of my 7000-series collection.

Also, I was wrong about the traces not responding to controls: I can get those wiggly radial traces to shimmy a little bit by adjusting the horizontal position knob.

The plug-ins, aside from the knob damage, appeared good to a cursory inspection (I gave the scope a once over before I plugged her in. I'm fool hardy, but I'm not completely reckless).

I would be very happy if the problem were just the plug-ins.

I'm waiting on the replacement fuse and capacitor (though, I guess they're not strictly necessary).

I tried connecting a probe and seeing if I could get any kind of trace from the calibration signals, but got nothing. Then I put the probe back on the scope it came from, and checked the 7623A's calibration signals and they look kind of wonky: the 2236 couldn't get a stable trace on them (I'll put pictures in the album).

Clearly this is a sick little scope. What fun!

-- Jeff Dutky


Re: Waking a slumbering 475

Michael A. Terrell
 

Jeff Dutky wrote:
Sadly I can not find an archive of the sci.electronics newsgroup from 2003,
Have you tried Google Groups? They have the entire original usenet archive as their starting point.


Re: Very Inexpensive 7623A, but Problems

Tom Lee
 

The readout seems basically ok, so the CRT is being deflected properly both horizontally and vertically. Were the plug-ins part of the unit, or are they known good ones from your collection?

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 2/12/2021 22:13, Jeff Dutky wrote:
I bought a very inexpensive 7623A on the auction site and it just arrived. The aluminum cover on the back was dented in, and there was some damage to the low voltage regulator board (the fuse was shattered and one ceramic capacitor was cracked). I replaced the fuse with the lowest amperage fuse I had (0.5A, but what was required was 0.15A, I've got the correct fuses, and replacement capacitor on order from Mouser), just so I could see if it would power up.

It does power up, but the image that appears on the screen is badly distorted, and does not seem to respond to horizontal of vertical position controls. I have put a picture in the following album: https://groups.io/g/TekScopes/album?id=260677

Any opinions on how boned I am? Is this fixable, or am I looking at a CRT replacement?

-- Jeff Dutky




Re: Very Inexpensive 7623A, but Problems

Bob Albert
 

Off the top of my head I would guess the CRT is toast.  I worked on a Leader scope with a somewhat similarly distorted display and there also I felt something awful had happened to the deflection plates.  Perhaps the unit has been dropped.
Bob

On Friday, February 12, 2021, 10:14:17 PM PST, Jeff Dutky <jeff.dutky@gmail.com> wrote:

I bought a very inexpensive 7623A on the auction site and it just arrived. The aluminum cover on the back was dented in, and there was some damage to the low voltage regulator board (the fuse was shattered and one ceramic capacitor was cracked). I replaced the fuse with the lowest amperage fuse I had (0.5A, but what was required was 0.15A, I've got the correct fuses, and replacement capacitor on order from Mouser), just so I could see if it would power up.

It does power up, but the image that appears on the screen is badly distorted, and does not seem to respond to horizontal of vertical position controls. I have put a picture in the following album: https://groups.io/g/TekScopes/album?id=260677

Any opinions on how boned I am? Is this fixable, or am I looking at a CRT replacement?

-- Jeff Dutky

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