Date   

Re: 067-0525-01 or equivalent needed.

Gif Sim
 

067-0525-02 is required in the tds784 calibration procedure
I did a search on the net but did not find anything
in the service manual it is called "Coupler, Dual-Input"
Does anyone in the group have some coupler photos or do they know how it is made (wiring diagram)?
thanks
simon


Re: Question, and shameless plug...

Bruce Lane
 

Honestly? I don't know. When I tried to power it, it acted like it was
coming on in that the LEDs and displays lit. However, I couldn't get a
trace out of it AND I started to smell burning component in less than a
minute. That's when I killed the power and relegated it to the 'Maybe
Later' pile.

Location-wise: Kent, WA. Southeast of Seattle.

On 11-Nov-20 17:00, Dave Daniel wrote:
Also, where are you located?

On Nov 11, 2020, at 19:59, Dave Daniel <kc0wjn@gmail.com> wrote:

I need a 7L14 parts mule. Would your 7L14 be suitable, or is it just in need of minor repair?

DaveD

On Nov 11, 2020, at 19:55, Bruce Lane <kyrrin@bluefeathertech.com> wrote:

Fellow Tekkies,

I've posted a couple of 7L series modules I have up on Ebay,
specifically a (working) 7L5 and a (non-functional) 7L14. Here's a link
if you're interested.

https://www.ebay.com/sch/i.html?_nkw=&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=98030-8803&_sargn=-1%26saslc%3D1&_salic=1&_fss=1&_fsradio=%26LH_SpecificSeller%3D1&_saslop=1&_sasl=bftbell&_sop=12&_dmd=1&_ipg=200&_fosrp=1
--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)


Re: Question, and shameless plug...

Dave Wise
 

Prototypes were referred to as "A phase" or "B phase", so your slashed 'o' is actually greek letter phi. You have B-phase prototype number four. B-phase units were built as if they were production, and if no problems cropped up, that's what went to production. I don't know whether the 7L14 development was troubled; your unit could be identical to production, or not.

Dave Wise
________________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Bruce Lane via groups.io <kyrrin=bluefeathertech.com@groups.io>
Sent: Wednesday, November 11, 2020 4:55 PM
To: TekScopes@groups.io
Subject: [TekScopes] Question, and shameless plug...

Fellow Tekkies,

I've posted a couple of 7L series modules I have up on Ebay,
specifically a (working) 7L5 and a (non-functional) 7L14. Here's a link
if you're interested.

https://www.ebay.com/sch/i.html?_nkw=&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=98030-8803&_sargn=-1%26saslc%3D1&_salic=1&_fss=1&_fsradio=%26LH_SpecificSeller%3D1&_saslop=1&_sasl=bftbell&_sop=12&_dmd=1&_ipg=200&_fosrp=1

With that out of the way -- I do have one question on the 7L14 unit. It
had the weirdest serial number label I've ever seen, in the form of an
uppercase B (Beaverton, I'm pretty sure) followed by what looks like a
lower-case 'o' with a vertical slash through it, and ending in a numeric
'4.'

My gut says this means it could have been a prototype. Yes? No? Other?

Thanks much!

--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)


Re: Question, and shameless plug...

Dave Daniel
 

Also, where are you located?

On Nov 11, 2020, at 19:59, Dave Daniel <kc0wjn@gmail.com> wrote:

I need a 7L14 parts mule. Would your 7L14 be suitable, or is it just in need of minor repair?

DaveD

On Nov 11, 2020, at 19:55, Bruce Lane <kyrrin@bluefeathertech.com> wrote:

Fellow Tekkies,

I've posted a couple of 7L series modules I have up on Ebay,
specifically a (working) 7L5 and a (non-functional) 7L14. Here's a link
if you're interested.

https://www.ebay.com/sch/i.html?_nkw=&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=98030-8803&_sargn=-1%26saslc%3D1&_salic=1&_fss=1&_fsradio=%26LH_SpecificSeller%3D1&_saslop=1&_sasl=bftbell&_sop=12&_dmd=1&_ipg=200&_fosrp=1

With that out of the way -- I do have one question on the 7L14 unit. It
had the weirdest serial number label I've ever seen, in the form of an
uppercase B (Beaverton, I'm pretty sure) followed by what looks like a
lower-case 'o' with a vertical slash through it, and ending in a numeric
'4.'

My gut says this means it could have been a prototype. Yes? No? Other?

Thanks much!

--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)





Re: Question, and shameless plug...

Dave Daniel
 

I need a 7L14 parts mule. Would your 7L14 be suitable, or is it just in need of minor repair?

DaveD

On Nov 11, 2020, at 19:55, Bruce Lane <kyrrin@bluefeathertech.com> wrote:

Fellow Tekkies,

I've posted a couple of 7L series modules I have up on Ebay,
specifically a (working) 7L5 and a (non-functional) 7L14. Here's a link
if you're interested.

https://www.ebay.com/sch/i.html?_nkw=&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=98030-8803&_sargn=-1%26saslc%3D1&_salic=1&_fss=1&_fsradio=%26LH_SpecificSeller%3D1&_saslop=1&_sasl=bftbell&_sop=12&_dmd=1&_ipg=200&_fosrp=1

With that out of the way -- I do have one question on the 7L14 unit. It
had the weirdest serial number label I've ever seen, in the form of an
uppercase B (Beaverton, I'm pretty sure) followed by what looks like a
lower-case 'o' with a vertical slash through it, and ending in a numeric
'4.'

My gut says this means it could have been a prototype. Yes? No? Other?

Thanks much!

--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)





Question, and shameless plug...

Bruce Lane
 

Fellow Tekkies,

I've posted a couple of 7L series modules I have up on Ebay,
specifically a (working) 7L5 and a (non-functional) 7L14. Here's a link
if you're interested.

https://www.ebay.com/sch/i.html?_nkw=&_in_kw=1&_ex_kw=&_sacat=0&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=98030-8803&_sargn=-1%26saslc%3D1&_salic=1&_fss=1&_fsradio=%26LH_SpecificSeller%3D1&_saslop=1&_sasl=bftbell&_sop=12&_dmd=1&_ipg=200&_fosrp=1

With that out of the way -- I do have one question on the 7L14 unit. It
had the weirdest serial number label I've ever seen, in the form of an
uppercase B (Beaverton, I'm pretty sure) followed by what looks like a
lower-case 'o' with a vertical slash through it, and ending in a numeric
'4.'

My gut says this means it could have been a prototype. Yes? No? Other?

Thanks much!

--
---
Bruce Lane, ARS KC7GR
http://www.bluefeathertech.com
kyrrin (at) bluefeathertech dot com
"Quando Omni Flunkus Moritati" (Red Green)


Re: 067-0525-01 or equivalent needed.

Glenn Little
 

It appears a BNC T adapter, two equal lengths is 50 Ohm coax and another 50 Ohm coax would create a dual input cable to serve this need.

Glenn

On 11/11/2020 7:31 PM, Raymond Domp Frank wrote:
On Wed, Nov 11, 2020 at 10:53 PM, Tom Lee wrote:

My guess (and it’s only that) is that they designed it to be enough better
than any DUT that you wouldn’t ever worry about the fixturing. A good stress
test, e.g, would be CMRR measurements at the upper end of the 485’s freq
range. Such a measurement is sensitive to phase match.
You guessed right as regards the 485, Tom.

A quick scan of the 485 Service Manual brings up the following:

Where test equipment for checking and adjusting is specified, a "Dual Input Cable" is listed, with a 067-0525-00 as an "Example of Applicable Test Equipment".

In the "Performance Check" chapter, CMR is checked, both at 50 Ohm and at 1 MOhm.

First, a 50 kHz sine wave is applied to both channels (using the 067-0525-00). Vertical sensitivity is set to 20 mV/div on both channels and amplitude is set to 8 divisions vertical deflection. With CH2 set to INVERTED and vertical mode display set to ADD, CH2 VARIABLE GAIN is set to minimize the displayed resulting amplitude.

Next, 50 MHz is applied and the resulting amplitude is checked against a 0.8 div. maximum spec.

My rough (very rough/wrong?) calculation suggests that apart from the 485's behavior, a 300 ps phase difference between both inputs could cause this. That'd be the result of a length difference of 2.5" between both cables.

The test is repeated with input impedance set to 1 MOhm with 50 Ohm terminations on the inputs.

The 067-0525-00 is also used for checking Added Mode Gain by applying equal amplitude signals to CH1 and CH1. Any good quality signal splitting cable would do the job, as it would for the 7A22

Raymond



--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: Troubleshooting an old Tek 475

Roy Thistle
 

On Sat, Nov 7, 2020 at 07:56 PM, Paul Amaranth wrote:


There's a couple of really nice designs on the eevblog.
also don't forget there is a whole group dedicated to ESR meters at...
https://groups.io/g/ESR-Meters-North
... of course, there hasn't been any posts for almost 6 months.


Re: 067-0525-01 or equivalent needed.

 

On Wed, Nov 11, 2020 at 10:53 PM, Tom Lee wrote:


My guess (and it’s only that) is that they designed it to be enough better
than any DUT that you wouldn’t ever worry about the fixturing. A good stress
test, e.g, would be CMRR measurements at the upper end of the 485’s freq
range. Such a measurement is sensitive to phase match.
You guessed right as regards the 485, Tom.

A quick scan of the 485 Service Manual brings up the following:

Where test equipment for checking and adjusting is specified, a "Dual Input Cable" is listed, with a 067-0525-00 as an "Example of Applicable Test Equipment".

In the "Performance Check" chapter, CMR is checked, both at 50 Ohm and at 1 MOhm.

First, a 50 kHz sine wave is applied to both channels (using the 067-0525-00). Vertical sensitivity is set to 20 mV/div on both channels and amplitude is set to 8 divisions vertical deflection. With CH2 set to INVERTED and vertical mode display set to ADD, CH2 VARIABLE GAIN is set to minimize the displayed resulting amplitude.

Next, 50 MHz is applied and the resulting amplitude is checked against a 0.8 div. maximum spec.

My rough (very rough/wrong?) calculation suggests that apart from the 485's behavior, a 300 ps phase difference between both inputs could cause this. That'd be the result of a length difference of 2.5" between both cables.

The test is repeated with input impedance set to 1 MOhm with 50 Ohm terminations on the inputs.

The 067-0525-00 is also used for checking Added Mode Gain by applying equal amplitude signals to CH1 and CH1. Any good quality signal splitting cable would do the job, as it would for the 7A22

Raymond


Re: 2252 boards

Reddy
 

Arlington, Virginia. What are you interested in?

Reddy


Re: 067-0525-01 or equivalent needed.

Tom Lee
 

My guess (and it’s only that) is that they designed it to be enough better than any DUT that you wouldn’t ever worry about the fixturing. A good stress test, e.g, would be CMRR measurements at the upper end of the 485’s freq range. Such a measurement is sensitive to phase match.

Tom

Sent from my iThing, so please forgive brevity and typos

On Nov 11, 2020, at 13:27, Eric <ericsp@gmail.com> wrote:

OK I can understand that. But if the parameters are able to be so loose then why is this calibration fixture specified for so many different types of modules and scopes. 465 non B, 465B, 485, 7a26, 7A18, 7a22, to name a few. Is it a case of Tek made it so might as well use it? As far as I know this is just RG58 coax just with a tight tolerance on the length.





Re: 067-0525-01 or equivalent needed.

Glenn Little
 

Why not build one?

Glenn

On 11/11/2020 3:01 PM, Eric wrote:
I need this calibration fixture or something like it to calibrate a 7A22 and some 400 series scopes. This fixture is a BNC Y cable the important part is the Y side of the cable is matched length to within 0.1 inch. This is to remove cable aberrations and phase difference to the inputs. I don’t necessarily need the 067-0525 if I can order a matched length Y cable from somewhere.



--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@arrl.net AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: 067-0525-01 or equivalent needed.

Eric
 

OK I can understand that. But if the parameters are able to be so loose then why is this calibration fixture specified for so many different types of modules and scopes. 465 non B, 465B, 485, 7a26, 7A18, 7a22, to name a few. Is it a case of Tek made it so might as well use it? As far as I know this is just RG58 coax just with a tight tolerance on the length.


Re: 067-0525-01 or equivalent needed.

Tom Lee
 

I was in the middle of composing a reply when Raymond's post popped up. He's absolutely right. There is absolutely no need to be so fussy about matching physical/electrical lengths to the degree you are talking about.

So-- "what he said". :)

--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 11/11/2020 12:01, Eric wrote:
I need this calibration fixture or something like it to calibrate a 7A22 and some 400 series scopes. This fixture is a BNC Y cable the important part is the Y side of the cable is matched length to within 0.1 inch. This is to remove cable aberrations and phase difference to the inputs. I don’t necessarily need the 067-0525 if I can order a matched length Y cable from somewhere.




Re: Tek/Sony 308 ROMs

Peter H
 

Yep, that's what I wrote earlier - "chip selects that were apparently also mask programmable".
The 2316 in U430 is code at address 0x0000 whereas the other 2316 chip is the character generator and as such is always enabled.


Re: 067-0525-01 or equivalent needed.

-
 

The HP (Vector) Network Analyzers such as the HP 8754 use cables that are
matched in both electrical phase and amplitude, perhaps you can find a set
or even just a pair of these cables and use them. I think that the HP 8754
uses a set of four "matched cables" per HP but I think that only three of
the cables actually need to be matched.

On Wed, Nov 11, 2020 at 3:01 PM Eric <ericsp@gmail.com> wrote:

I need this calibration fixture or something like it to calibrate a 7A22
and some 400 series scopes. This fixture is a BNC Y cable the important
part is the Y side of the cable is matched length to within 0.1 inch. This
is to remove cable aberrations and phase difference to the inputs. I don’t
necessarily need the 067-0525 if I can order a matched length Y cable from
somewhere.






Re: 067-0525-01 or equivalent needed.

 

On Wed, Nov 11, 2020 at 09:01 PM, Eric wrote:


I need this calibration fixture or something like it to calibrate a 7A22 and
some 400 series scopes. This fixture is a BNC Y cable the important part is
the Y side of the cable is matched length to within 0.1 inch. This is to
remove cable aberrations and phase difference to the inputs. I don’t
necessarily need the 067-0525 if I can order a matched length Y cable from
somewhere.
There is no model in the 4xx 'scope series, much less a 7A22, that would require length matching to a maximum of 0.1". The 7A22 is a LF amplifier with a maximum bandwidth of 1 MHz, the fastest 4xx-series 'scope (485) has a bandwidth of 350 MHz.
Signal velocity in common 50 Ohm coax (0.67 c) or is about 12 ps per 0.1", quite invisible to any of these instruments.
For a 7A22 a good quality splitter with two lengths of good quality 50 Ohm coax with ordinary tolerance will suffice. A 485 will not show anything below 100 ps phase difference at best.

Raymond


067-0525-01 or equivalent needed.

Eric
 

I need this calibration fixture or something like it to calibrate a 7A22 and some 400 series scopes. This fixture is a BNC Y cable the important part is the Y side of the cable is matched length to within 0.1 inch. This is to remove cable aberrations and phase difference to the inputs. I don’t necessarily need the 067-0525 if I can order a matched length Y cable from somewhere.


Re: Another A5 board repair attemp - help needed

Rogerio O
 

Thank you Siggi,
I have been busy today, but I will have time to work on the scope tomorrow morning and I hope I can fix it after studying this new thread.
Roger


Re: PG506 calibration unit question

Tom Lee
 

Great job, Bill! That beast is one of the more jam-packed PIs of the series. I know what a PITA it can be to work on, so way to hang in there!

--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 11/11/2020 10:35, Bill E wrote:
Whew. After replacing the ps caps, voltages ok but various functions didn't. Function, that is. Put in the mica washer, all better. Yep, it was there for a reason, that reason obviously to correct a layout error on the board. But wait, the var amplitude wouldn't var. A tedious bit of schematic reading, test probing, the problem tuned out to be one contact in the switch associated with the var button, stuck closed. Even more tedious disassembly, managed to get that working. Now, finally, everything works. Even the calibration is pretty good. Isn't all this stuff fun?

Bill



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