scanned: Common Parts Design Catalog #3, Materials, April 1989
This scan was made possible by Pete Lancashire.
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Hello Mark,
Regarding Q1484, besides meter check, what is it actually / what's marked on it?
I ask because if this 464 has ever been attempted repair, and if this transistor has been replaced (I.e. by an industry standard stock part), it can very well not oscillate at all.
Mine had a defective transformer that would oscillate and work normally while cold, but would leak H.V. after warmed up so, I had to replace the transformer as one of the first repairs.
After I replaced the transformer and assembled every thing back together, I probably shorted something, when I applied power it didn't work and ultimately I found out that I burned Q1484 (never found the cause).
After I got a Q1484 burnt it started my quest to find a replacement and that was when I learnt this oscillator is very picky about the transistor and that Tek had 3 or 4 different part numbers for this same base transistor (which is a 2N3055 of the old manufacturing process, a MESA transistor), every part number hand picked to meet a specific parameter, for lower gain, or for lower ft.
In this group (you can still find the thread if you search for Tek464), David Hess taught me all that and suggested me to try a 2N3772, which didn't work for me, and then I tried an MJ15015, which did work, but neither me nor David could make sense of this, because the MJ 15015 is a new part, which has an ft much higher than the old MESA 2N3055, which where specifically selected for Tek, for the lowest ft (in the 800kHz range).
Made sense or not, the fact is that selecting a transistor that will work in this circuit is tricky and if yours have been replaced, this may very well the problem at your hand right now.
If, however, it's a Tek part with the correct part number, and if it doesn't seem to be damaged, then I think you may relax in this department and look further.
Another chapter of my quest, when the new transformer arrived and the transistor got burnt, of course that first thing that crossed my mind was that my supposedly N.O.S. transformer I got from Sphere could be bad... So before replacing the transistor I needed to find a way to test the transformer, at least for basic functionality.
I had success in testing the transformer somewhat well feeding its primary from a square wave generator (TTL level, with some resistance in series, like 330R or the like), then, while monitoring the voltage drop on the primary (with a scope), I swept the frequency until it peaked (which happened around 30kHz), and then I was able to measure the output of the feedback winding (Q1484 removed), and of the 600V (peak) winding.
Of course, the obtained voltage outputs were proportional to the actual peak to peak voltage that I was seeing at the primary, knowing that the peak to peak voltage on the primary, on a functional oscilloscope is about 30vpp.
Maybe you can apply the same technique to have a guess about the state of your transformer.
Please let us know,
Rgrds,
Fabio
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On Tue, Aug 21, 2018 at 11:13 AM, <kickingypsy9@...> wrote:
first thank you for your your help Fabio. i did everything you sugested.she's
stuck.i replaced c1487,no change.i checked q1484 out of circuit with my fet
analouge meter.checks good,no e to c leakage.i resoldered T1501,no change.when
i power unit on,pin 3 goes to + .5 v .i looked at it with my scope,it never
went negitive, just clean + .5 v dc. im on a mission to fix this unit.the
schematic does not give any resistence checkes on the windings of T1501.cant
find the replacement 120-0909-00 any where.any more sugestions on circuit
checks ? P.S. YOU DA MAN !
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first thank you for your your help Fabio. i did everything you sugested.she's stuck.i replaced c1487,no change.i checked q1484 out of circuit with my fet analouge meter.checks good,no e to c leakage.i resoldered T1501,no change.when i power unit on,pin 3 goes to + .5 v .i looked at it with my scope,it never went negitive, just clean + .5 v dc. im on a mission to fix this unit.the schematic does not give any resistence checkes on the windings of T1501.cant find the replacement 120-0909-00 any where.any more sugestions on circuit checks ? P.S. YOU DA MAN !
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Re: scanned: Common Parts Design Catalog #1 + Agilent/hp users group
Kurt & Pete,
Thank you so much. It takes a village to keep old Tektronix CRT stuff alive. Glad to warm myself by this village fire.
Kindest regards,
George
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On Aug 20, 2018, at 8:00 AM, walter shawlee <walter2@...> wrote:
many thanks for the IC catalog scan. excellent!
the hp/agilent users group has also moved to this server.
you can now find them at:
/g/HP-Agilent-Keysight-equipment
all the best,
walter
--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:-
We're all in one boat, no matter how it looks to you. (WS2)
All you need is love. (John Lennon)
But, that doesn't mean other things don't come in handy. (WS2)
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I am offering these to the members first before Ebay. I am parting out three 475's so have three good CRT's for offer have tested them all come on have a trace and trace moves with vert. and horizontal position controls.
These were damaged or incomplete scopes missing vertical side and other parts also bunch of broken knobs.
Also have the HV stuff if needed plus CRT tunnel stuff. Have two A9 main boards look in good condition and main transformers some case stuff, delay coil etc.
Asking $65.00 for each plus shipping, ask about other stuff on price. These are real clean look very nice.
Jim O
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Re: Machinable Potting Material ???
Paul,
Devcon makes two metal filled epoxies which would probably not make great potting material because of conductivity. They are outstanding repair materials however. The original one is Devcon A. It is steel filled epoxy putty and is very similar to JB Weld. The two Devcon F compounds are aluminum filled epoxy. The original Devcon F is just like Devcon A except for the aluminum content. However, Devcon F-2 is POURABLE! It would probably work well for what you intend. I was told years ago that these materials were 80% metal although I do not know how they do it. I had a cracked injection mold years ago which we needed to get some parts out of before it went out for repair. High temp Devcon saved our butts!
Jack Reynolds
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Re: scanned: Common Parts Design Catalog #1 + Agilent/hp users group
many thanks for the IC catalog scan.? excellent! the hp/agilent users group has also moved to this server. you can now find them at: /g/HP-Agilent-Keysight-equipmentall the best, walter -- Walter Shawlee 2 Sphere Research Corp. 3394 Sunnyside Rd. West Kelowna, BC, V1Z 2V4 CANADA Phone: +1 (250-769-1834 -:- We're all in one boat, no matter how it looks to you. (WS2) All you need is love. (John Lennon) But, that doesn't mean other things don't come in handy. (WS2)
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Re: scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
Very valueable, must be a lot of work those hundreds of pages. And al text-searchable.
Thanx for both of you, Ren¨¦
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Re: scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
Glad to help. More coming.
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Re: scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
Ditto. These are great!
-- john, KE5FX
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Raymond Domp Frank
Sent: Sunday, August 19, 2018 3:59 PM
To: [email protected]
Subject: Re: [TekScopes] scanned: Common Parts Design Catalog #4, Electro-
Mechanical, Jan 1989
Thanks a lot, Pete and Kurt!
Raymond
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Re: scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
Thanks a lot, Pete and Kurt!
Raymond
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Re: scanned: Common Parts Design Catalog #1, Integrated Circuits, Jan 1987
Thanks a lot, Pete and Kurt!
Raymond
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Re: scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
Great reference and a very nice scan. Thanks!
Bob.
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-----Original Message----- From: Kurt Rosenfeld Sent: Sunday, August 19, 2018 12:23 PM To: [email protected]Subject: [TekScopes] scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989 This scan was made possible by Pete Lancashire.
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scanned: Common Parts Design Catalog #1, Integrated Circuits, Jan 1987
This scan was made possible by Pete Lancashire.
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Re: tektronix 214 option 94/ Li-Ion fork
Hi Miguel,
What modifications did you make to the charger circuit to adjust it for the
different charging requirements (current limits, voltage cutoff point, etc)
of Li batteries compared to NiCd batteries.
Can you do a test with the scope on (two traces on the screen) with a fully
charged set of batteries and see how long it lasts.
Dennis Tillman W7PF
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-----Original Message-----
From: Miguel Work
Sent: Saturday, August 18, 2018 11:00 AM
Subject: Re: [TekScopes] tektronix 214 option 94/ Li-Ion fork
Hi!
My tektronix 214,221 and 222 is now working with lithium batteries.
/g/TekScopes/photo/66992/1?p=Name,,,20,1,0,0
/g/TekScopes/photo/66992/2?p=Name,,,20,1,0,0
Regards
Miguel
-----Mensaje original-----
De: Kevin> Oconnor
Enviado el: s¨¢bado, 18 de agosto de 2018 4:02
Asunto: Re: [TekScopes] tektronix 214 option 94/ Li-Ion fork
I wouldn't pick to much on Li-Ion chemistry. There are a lot of deployed
chemistries and construction methods. Some have problems some don't,
just like NiCd & NiMH. I've seen plenty of NiCD rotting in their
electronics. Neither Ni has much shelf life, yet I have seen some Li
devices wake up after a year on the shelf.
Realistically, all these chemistries have quirky charging and
discharging requirements. But if I am designing new hardware for the
masses, it is highly unlikely I would be successful selecting NiCd
chemistry. Yes, Li-Ion needs a different charging means, but there chips
and PCBs for that. Yes, they can balloon and catch fire sometimes. That
is a manufacturing QC issue.
Given the choice between a coin NiCd and a postage stamp Li-Ion for a
little rechargeable gizmo device, I'd pick the Li battery every time.
The coin Ni-Cd is soooo Palm-Pilot era!!!!!
Kjo -- Dennis Tillman W7PF TekScopes Moderator
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Re: tektronix 214 option 94
On Sun, 19 Aug 2018 13:38:55 -0700, you wrote:
Scope probes are not detachable for any 211, 212, 213, or 214 scope.
Not in normal use, no. Unfortunately, there's a lot of them where someone just took the probes anyway, they do plug in, but it's internal. Ask me how I found this out... Harvey Dennis Tillman W7PF
-----Original Message-----
From: > Colin Herbert
Sent: Saturday, August 18, 2018 12:02 PM
Subject: Re: [TekScopes] tektronix 214 option 94
This scope is currently on eBay. If it is of any significance, the
probes are permanently wired in, according to the description.
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Miguel Work
Sent: 16 August 2018 10:25
To: [email protected]
Subject: [TekScopes] tektronix 214 option 94
Which is optino 94 for a Tektronix 214?
/g/TekScopes/photo/66992/0?p=Name,,,20,1,0,0
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Re: tektronix 214 option 94
Scope probes are not detachable for any 211, 212, 213, or 214 scope.
Dennis Tillman W7PF
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-----Original Message-----
From: > Colin Herbert
Sent: Saturday, August 18, 2018 12:02 PM
Subject: Re: [TekScopes] tektronix 214 option 94
This scope is currently on eBay. If it is of any significance, the
probes are permanently wired in, according to the description.
Colin.
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of
Miguel Work
Sent: 16 August 2018 10:25
To: [email protected]
Subject: [TekScopes] tektronix 214 option 94
Which is optino 94 for a Tektronix 214?
/g/TekScopes/photo/66992/0?p=Name,,,20,1,0,0 -- Dennis Tillman W7PF TekScopes Moderator
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Re: 7L13, more exact frequency readout
Hi again Now I have done quite a few measurements with my 7L13. I just used a know frequency source to tune it into the frequency I am searching for and then I do the measurement. This works well enough for my zero span measurements with resolution of 300kHz. I did buy a frequency meter for up to 5.8GHz and tried to correlate the frequency of the YIG oscillator with the voltage between pin 6 of U2110 and ground with a more precise voltage measurement than the frequency readout contains. Regarding phase locking of LO1. According to the manual, the span is done in the following way: = 5MHz/div: Main coil of the YIG 2MHz/div to 100kHz/div: FM-coil <=50kHz/div: The phase lock loop of LO2, and then the LO1 can be phase locked. I found out that the plugin need through calibration since the center frequency moves quite a lot with changing span. But the nice thing is that I think I have solved the EMC problem the setup was supposed to help solving and my 7L13 is very helpful in my EMC precompliance toolset. Regards Gudjon
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scanned: Common Parts Design Catalog #4, Electro-Mechanical, Jan 1989
This scan was made possible by Pete Lancashire.
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Fabio Trevisan
Glydeck
Raymond Domp Frank