Trivia- can you identify these probes/probe accessories circa 1960 (or before)?
This past weekend I bought a 310A in a leather carrycase with several probes and probe accessories. Nice! The 310A will be a future project- haven't even tried to power it up yet. Included several types of probe tips I may never find a use for.
In the case were a few things I can't identify. If you can, please also tell if there is a proper way (or improper way) to use them, and maybe why they aren't (evidently) used/manufactured anymore.
Photo A: some type of scope input connector (not sure if you'd call it a probe):
Photo B: some kind of probe accessory/tip (the black screw-on connectors were packaged for/by IBM if that's any clue):
Photo C: evidently a Tek probe, but no markings other than "600V Max, 10 Meg, 14uuF, Atten 10X") around the base end. Cable is a Amphenol No. 621-685:
What's the teflon screw intended for? The access for compensation is on the other side.
Cheers,
Keith Ostertag
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Question regarding 465B "free running"
If I turn both channels off, I get a "free running" trace. This trace is not vertically centered. Is it supposed to be centered? If so, is there an adjustment for that and where is it?
Thanks,
Barry - N4BUQ
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Re: 2205 channel 1 problem
Here's what I got for voltages. Values in brackets are what is printed on the schematic.
Q102e: +4.84 [-4.7]
Q102b: +4.12 [not printed, but assumed about +4.3]
Q102c: -3.45 [-4.2]
Q103e: +4.53 [-4.7]
Q103b: common to Q102b +4.12
Q103c: -4.44 [-4.2]
Q104e: -3.85 [-4.9]
Q105e: -5.26 [-4.9]
U30pin2: +0.58 [0v]
Clearly something is messed up here.
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Thanks Curly- doubt I'll ever need to put one in there but interesting anyway!
Cheers
DaveB, NZ
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Show quoted text
----- Original Message ----- From: "curlytronics" <curlytronics@...> To: <TekScopes@...> Sent: Monday, July 02, 2012 12:34 PM Subject: [TekScopes] Re: Tek 602 Display Unit My 602 fan is a square boxer, roughly 3.5in x 3.5in x 1.5in. Curly --- In TekScopes@..., "Dave Brown" <tractorb@...> wrote:
How big is the fan?
No fan in mine, BTW.
DaveB, NZ
----- Original Message -----
From: "curlytronics" <curlytronics@...>
To: <TekScopes@...>
Sent: Sunday, July 01, 2012 11:01 AM
Subject: [TekScopes] Re: Tek 602 Display Unit
Hello Hakan,
It is definitely a professional installation. The fan assembly would have
to be manufactured from scratch and the chassis rear plate would have to be
manufactured from scratch. I did compare a known stock 602 chassis rear
plate to my 602 chassis rear plate. They are very different.
Curly
--- In TekScopes@..., "Hakan H" <hahi@> wrote:
--- In TekScopes@..., "curlytronics" <curlytronics@> wrote:
Two questions about the Tek 602 display unit--
Does anyone know what the *Mod 174K* is?
My 602 has a Tek factory installed fan. Has anyone ever seen one like
this and/or have the fan schematic?
Curly
-------------
602 mod 174K was a special CRT. As I interprete the info it came with
an internal graticule of a 8 x 10 cm border only and an external
8 x 10 graticule. Apparantly it was offered with four different
phosphor types were P31 was, or became, the same as opt2.
Can't find any info on the fan. Are you sure it was factory installed (by
Tek) ?
/H???kan
------------------------------------
Yahoo! Groups Links
------------------------------------ Yahoo! Groups Links
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Re: 7B92A with tunnel diodes vs. version without
On Sun, 1 Jul 2012 20:59:15 -0600, David DiGiacomo <daviddigiacomo@...> wrote: On Sun, Jul 1, 2012 at 5:29 PM, raymonddompfrank <r.domp.frank@...> wrote:
Recently, I acquired a 7B92A that in contrast with the unit that I had, turns out to have no (discrete?) tunnel diodes in the trigger circuits but instead, uses hybrids packaged like the ones in e.g. a 7904A's vertical amp. I have seen references to this newer version of the 7B92A but haven't been able to find any description of the reasons why and any possible consequences. I would guess (and could appreciate) lower cost, higher reliability?
I wonder whether the circuits in these hybrids still contain circuits with tunnel diodes or do they contain more traditional circuits and if so, are there any functional differences? i could imagine that the maximum signal that the unit will trigger on would be lower than the tunnel diode-equipped version. No, there are no tunnel diodes in the late version. I thought the
trigger circuits were monolithic ICs, but maybe not.
I have found the early version to be faster, but others disagree. I only have the later 7B92 plug-ins or I would do some tests. Both versions include the HF Sync mode. I like them because they trigger more cleanly than the 7B53A which is to be expected. I thought they used monolithic ICs instead of hybrids also but that could still be the case. Tektronix may have used that package for an IC simply because it was the highest frequency IC package available to them. It is too bad there are no details on it.
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Hi all,
I agree, the 547 is an absolute classic and I still use one of mine as the preferred bench scope even though I have plenty of higher performance scopes if I need them. I hope someone local agrees to take yours and use it as it was meant to be used. They will outlast me and I only hope I can find someone to cherish my two 547s one day.
Morris
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--- In TekScopes@..., "fred" <fredschneider@...> wrote:
Lets start a "save the 547" foundation ;-) but no kidding, the 547 is in my opinion the nicest scope ever. I have a very nice example here on a tek mobile. It s huge and I have not much space but I allways keep it, and alltough I have several scopes from 7704 to a modern 350MHz DSO i still use it regular. It would be a terrible waiste to part it.
Fred
--- In TekScopes@..., Ken Chalfant <kpchalfant@> wrote:
Hi Scott,
At first thought I did not wish to splatter my thoughts about your 547 all over the internet. However, as I wrote this email I changed my mind. My hope is that at the same time my thoughts would encourage you to hold off and sell the scope in tact, my thoughts might also inspire someone to give it a new home and put it to good use. I hope all of you, especially Scott, forgive my rambling thoughts.
The 547 is a special scope to me. When I landed my first full time technician job, just out of high school in 1971, the company for which I went to work purchased a new 547 the same month. I was one of the first to use that 547 and it was the most magnificent scope I had ever seen.
Of course, at that time I really hadn't been exposed to many different scopes - but enough to know this was something special. Ultimately, I moved on to a better job and later that company went out of business and I showed up and bought that 547. It was my main scope for the next twenty years. Later I upgraded to 7000 series scopes, but in many ways they were not better than the 547 - especially image sharpness.
Now I use DSO's and the two remaining 7000 scopes I own rest patiently in a warehouse.
It was in 2010 when I finally decided to find my 547 a new home. Except for replacing a tunnel diode in the trigger circuit that scope had never required service and was fully functional, with some noisy pots, when I pulled it out of my warehouse and shipped it to its new owner.
As a sidebar, the new owner asked me to send it by Greyhound bus-line. I packed it extremely well in a huge, heavy duty, cardboard box which I double lined with additional cardboard. It weighed out at 98 pounds and the shipping charge was around $100.00. I delivered it to the bus depot in Colorado Springs, Colorado on 11-JUN-2010. They indicated it would arrive at the Northampton, Massachusetts on or about 14-JUN-2010.
For the next three weeks they had no idea where it was. They were unable to track it in any way and both the new owner and I had nearly given up when it arrived in Northampton on 05-JUl-2010 in perfect condition.
Forgive the walk down memory lane, but my point is that the 547 is an extraordinary scope and if yours is complete and functional I strongly encourage to resist parting it out. Too much of that is happening to both Tektronix and HP equipment that will never be replaced or recovered.
If both seller and buyer are patient, and the packing is exceptionally robust the scope can be shipped across country for a modest amount.
I hope you decide to sell it intact to someone interested in using it as a bench scope in their shop - a service for which it is so elegantly intended.
There is no doubt that many 500 series scopes have been cannibalized for parts, and when something such as the CRT or main transformer fail that may well be the most appropriate choice to help keep other Tek scopes alive and in service.
I hope you find your 547 a safe and good home.
Please know I intend no offense - I just love 547's.
Warm regards,
Ken
On 30Jun, 2012, at 6:00 AM, Scott wrote:
I have a complete 547 scope here and I'm willing to either
1. Sell it ALL cheap
or 2.
Part it out to those who need parts and dont wanna spend their kid's tuition to ship it.
Let me know and HAVE A GREAT 4th!!
Scott in Vermont ( or, as I lovingly call it , Vietmont)
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Re: 7B92A with tunnel diodes vs. version without
On Sun, Jul 1, 2012 at 5:29 PM, raymonddompfrank <r.domp.frank@...> wrote: Recently, I acquired a 7B92A that in contrast with the unit that I had, turns out to have no (discrete?) tunnel diodes in the trigger circuits but instead, uses hybrids packaged like the ones in e.g. a 7904A's vertical amp. I have seen references to this newer version of the 7B92A but haven't been able to find any description of the reasons why and any possible consequences. I would guess (and could appreciate) lower cost, higher reliability?
I wonder whether the circuits in these hybrids still contain circuits with tunnel diodes or do they contain more traditional circuits and if so, are there any functional differences? i could imagine that the maximum signal that the unit will trigger on would be lower than the tunnel diode-equipped version. No, there are no tunnel diodes in the late version. I thought the trigger circuits were monolithic ICs, but maybe not. I have found the early version to be faster, but others disagree.
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Re: Help with R7903 needed, some success...
On Mon, 02 Jul 2012 01:09:13 -0000, "keithostertag" <keitho@...> wrote: More photos of traces, if you could look over and help explain I would appreciate it.
I finally got the PS out of tic mode, though I have to "warm it up" first by powering it on with a heavy load on +5L for a few minutes, turn it off, then reconnect P1417 immediately and power back up. So now I can test the PS in somewhat normal mode (no CRT yet.)
As recommended, I began to look at the power supply calibration procedure. But I got stopped at the first step- TP1625 to ground measures less than 11 volts. According to the SM it should be 55V plus-or-minus 25V (should that be .25V?). Adjusting R1231 all the way CW only gives about 11.3V. What is the voltage at the anode of VR1297 and what is the -17 volt supply feeding it? If that reference is off then the +130 volt supply will be off and TP1625 will be off indicating that the -3KVolt supply may be out of regulation. If the +130 volt supply is in regulation, then I would start looking for a problem on the high voltage side or more bad electrolytics. After looking around for quite sometime I found that I am only getting a little more than 10VAC p-p off one side of T1235. Shouldn't I be getting more than twice that? Or am I misinterpreting that? 10VACpp seem about right. The 20 volt zener diode VR1279 is just there to protect the IC. The output of T1235 is a current so the peak to peak voltage is made up of the 7.5 volt shunt regulator at pin 6 of U1275, 1.8 volts from CR1288 to CR1290, the low voltage drop across current sense resistor R1287, and 1.2 volts from bridge rectifier CR1280 to CR1283. That all adds up to about 10.5 volts peak to peak. I am getting about 300V p-p at TP1238, TP1231 and TP1234. is that too low?
We already discussed the two large power supply caps C1216 and C1217- they have checked out OK AFAIK.
I won't be using my isolation transformer again until I can replace it with a better one, so I may be limited in what I can safely do.
Here are some photos:
One side of T1235 (note timebase):
TP1238 (bottom of C1229, one side of VR1239):
TP1231 (same as TP1234):
So the main question is to find out why TP1625 is so low, and this is my attempt to trace the problem back to its origin.
I'm confused about how to calculate the expected voltages- if TP1238 is 300VAC p-p, and T1235 turns ratio is 1:55, should the output of T1235 be 300/55 = ~ 5.5 VAC p-p? But then how could we get near 55V at TP1625? T1235 is used as a current transformer. The circuit making up the shunt regulator on the 55 turn output looks like a short to the 1 turn primary. The secondary is limited to about 10 Vpp so the primary will be 10/55 or about 180 mVpp. BTW- using my DMM, U1275 pin 6 is about 7.06V (should be 7.5) and pin 7 is -1.92 (should be -2). Voltage across the 20V zener VR1279 is only about 9.75V. The zener is just there to protect the IC.
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Re: 7B92A with tunnel diodes vs. version without
The early 7B92A had amplifiers in the signal path before the tunnel diodes. Amplifiers help keep the tunnel diodes safe, but they tend to reduce trigger bandwidth. Contrast this with the 5T1A of a decade earlier, where the trigger signal is passively coupled to the "trigger recognition" tunnel diodes. The 5T1A is electrically fragile because of this design.
Also, the fastest triggering is really "HF sync" mode, not true bistable-multivibrator mode. HF sync mode exists in several Tek products using passive coupling of the trigger input to the tunnel diode (e.g., 7T11, 5T3, 519).
-Kurt
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--- In TekScopes@..., "raymonddompfrank" <r.domp.frank@...> wrote:
Of course, where I wrote "...the maximum signal that...", I meant to write "...the maximum *frequency* that..."
Sorry for the inaccuracy.
Raymond
--- In TekScopes@..., "raymonddompfrank" <r.domp.frank@> wrote:
Recently, I acquired a 7B92A that in contrast with the unit that I had, turns out to have no (discrete?) tunnel diodes in the trigger circuits but instead, uses hybrids packaged like the ones in e.g. a 7904A's vertical amp. I have seen references to this newer version of the 7B92A but haven't been able to find any description of the reasons why and any possible consequences. I would guess (and could appreciate) lower cost, higher reliability?
I wonder whether the circuits in these hybrids still contain circuits with tunnel diodes or do they contain more traditional circuits and if so, are there any functional differences? i could imagine that the maximum signal that the unit will trigger on would be lower than the tunnel diode-equipped version.
I would much appreciate if any of you experts could shed some light on this.
Raymond
|
Re: Help with R7903 needed, some success...
More photos of traces, if you could look over and help explain I would appreciate it.
I finally got the PS out of tic mode, though I have to "warm it up" first by powering it on with a heavy load on +5L for a few minutes, turn it off, then reconnect P1417 immediately and power back up. So now I can test the PS in somewhat normal mode (no CRT yet.)
As recommended, I began to look at the power supply calibration procedure. But I got stopped at the first step- TP1625 to ground measures less than 11 volts. According to the SM it should be 55V plus-or-minus 25V (should that be .25V?). Adjusting R1231 all the way CW only gives about 11.3V.
After looking around for quite sometime I found that I am only getting a little more than 10VAC p-p off one side of T1235. Shouldn't I be getting more than twice that? Or am I misinterpreting that?
I am getting about 300V p-p at TP1238, TP1231 and TP1234. is that too low?
We already discussed the two large power supply caps C1216 and C1217- they have checked out OK AFAIK.
I won't be using my isolation transformer again until I can replace it with a better one, so I may be limited in what I can safely do.
Here are some photos:
One side of T1235 (note timebase):
TP1238 (bottom of C1229, one side of VR1239):
TP1231 (same as TP1234):
So the main question is to find out why TP1625 is so low, and this is my attempt to trace the problem back to its origin.
I'm confused about how to calculate the expected voltages- if TP1238 is 300VAC p-p, and T1235 turns ratio is 1:55, should the output of T1235 be 300/55 = ~ 5.5 VAC p-p? But then how could we get near 55V at TP1625?
BTW- using my DMM, U1275 pin 6 is about 7.06V (should be 7.5) and pin 7 is -1.92 (should be -2). Voltage across the 20V zener VR1279 is only about 9.75V.
Thanks for any insights you can give,
Keith Otstertag
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My 602 fan is a square boxer, roughly 3.5in x 3.5in x 1.5in.
Curly
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Show quoted text
--- In TekScopes@..., "Dave Brown" <tractorb@...> wrote:
How big is the fan?
No fan in mine, BTW.
DaveB, NZ
----- Original Message -----
From: "curlytronics" <curlytronics@...>
To: <TekScopes@...>
Sent: Sunday, July 01, 2012 11:01 AM
Subject: [TekScopes] Re: Tek 602 Display Unit
Hello Hakan,
It is definitely a professional installation. The fan assembly would have
to be manufactured from scratch and the chassis rear plate would have to be
manufactured from scratch. I did compare a known stock 602 chassis rear
plate to my 602 chassis rear plate. They are very different.
Curly
--- In TekScopes@..., "Hakan H" <hahi@> wrote:
--- In TekScopes@..., "curlytronics" <curlytronics@> wrote:
Two questions about the Tek 602 display unit--
Does anyone know what the *Mod 174K* is?
My 602 has a Tek factory installed fan. Has anyone ever seen one like
this and/or have the fan schematic?
Curly
-------------
602 mod 174K was a special CRT. As I interprete the info it came with
an internal graticule of a 8 x 10 cm border only and an external
8 x 10 graticule. Apparantly it was offered with four different
phosphor types were P31 was, or became, the same as opt2.
Can't find any info on the fan. Are you sure it was factory installed (by
Tek) ?
/H?kan
------------------------------------
Yahoo! Groups Links
|
Re: 7B92A with tunnel diodes vs. version without
Of course, where I wrote "...the maximum signal that...", I meant to write "...the maximum *frequency* that..."
Sorry for the inaccuracy.
Raymond
toggle quoted message
Show quoted text
--- In TekScopes@..., "raymonddompfrank" <r.domp.frank@...> wrote:
Recently, I acquired a 7B92A that in contrast with the unit that I had, turns out to have no (discrete?) tunnel diodes in the trigger circuits but instead, uses hybrids packaged like the ones in e.g. a 7904A's vertical amp. I have seen references to this newer version of the 7B92A but haven't been able to find any description of the reasons why and any possible consequences. I would guess (and could appreciate) lower cost, higher reliability?
I wonder whether the circuits in these hybrids still contain circuits with tunnel diodes or do they contain more traditional circuits and if so, are there any functional differences? i could imagine that the maximum signal that the unit will trigger on would be lower than the tunnel diode-equipped version.
I would much appreciate if any of you experts could shed some light on this.
Raymond
|
Re: 7704A Readout Capability
Hi,
Try running the readout intensity control throughout its range to make sure it is not sitting on a bad spot. Press your beam finder and see it dots appear above and below the reduced trace. Both plugins support readout. If you have not done so, get a manual and get familiar with your fine machine.
Jerry Massengale
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-----Original Message-----
From: dabyram
To: TekScopes
Sent: Sun, Jul 1, 2012 5:00 pm
Subject: [TekScopes] 7704A Readout Capability
?
I recently acquired a Tek 7704A with 7A26 and 7B53A plugins. The 'scope seems to operate fine except I have no readout functions on the CRT. I am not sure if these plugins have the capability or if there is a problem with the readout circuitry in the mainframe.
Any thoughts would be appreciated.
Tom
|
7B92A with tunnel diodes vs. version without
Recently, I acquired a 7B92A that in contrast with the unit that I had, turns out to have no (discrete?) tunnel diodes in the trigger circuits but instead, uses hybrids packaged like the ones in e.g. a 7904A's vertical amp. I have seen references to this newer version of the 7B92A but haven't been able to find any description of the reasons why and any possible consequences. I would guess (and could appreciate) lower cost, higher reliability?
I wonder whether the circuits in these hybrids still contain circuits with tunnel diodes or do they contain more traditional circuits and if so, are there any functional differences? i could imagine that the maximum signal that the unit will trigger on would be lower than the tunnel diode-equipped version.
I would much appreciate if any of you experts could shed some light on this.
Raymond
|
Re: 7704A Readout Capability
7000 series Plug-ins that lack readout capability have an N suffix. You could check if the 7704A has option 1 which removes the readout, look at the third of four potentiometers from the top which should be the readout intensity control, or look to see if the readout PC board is even inside. On Sun, 01 Jul 2012 22:00:24 -0000, "dabyram" <tom.byram@...> wrote: I recently acquired a Tek 7704A with 7A26 and 7B53A plugins. The 'scope seems to operate fine except I have no readout functions on the CRT. I am not sure if these plugins have the capability or if there is a problem with the readout circuitry in the mainframe.
Any thoughts would be appreciated.
Tom
|
I recently acquired a Tek 7704A with 7A26 and 7B53A plugins. The 'scope seems to operate fine except I have no readout functions on the CRT. I am not sure if these plugins have the capability or if there is a problem with the readout circuitry in the mainframe.
Any thoughts would be appreciated.
Tom
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I have uploaded the Tektronix schematics for the CFG280 and the manual for the CMC250 to BAMA. The CFG280 schematics are all 11 X 17" size and both are in pdf format. Thanks to Stan Griffiths for loaning me the documents so we all can share this resource.
Reed Dickinson
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Error code list for Tektronics TDS scopes
I was wondering if anyone knew where a list of error codes was for the TDS6xxx series oscilloscopes.
Specifically, I have a TDS6604 with an error code of 531 on the calibration test, which appears to be a memory storage error from the materials I could fine.
Thanks all! :D
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535A with 10 Plug-ins in Denver
I have no affiliation with the seller.
-Kurt
|
Feel free to check out a site I run:
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David Hess