开云体育

?

I got one too but without the supply, I made two bananaplugs on the wire ( by splitting it so the original connector is still there. I used it a few times on a max 1A bench supply set at 12V.

The guy who gave it to me told me it worked on 12V , he had one too with the original adapter, so I did, but I used it only a few times for some home made currentprobes.?

Since a few weeks I have a very nice P6016, it was not made for this amplifier but it works wonderfull and accurate.

So I was thinking about making a fixed psu for it that gets its power from the rail build in the tekmobile. But now I read 24V Volt ? are there more versions or was he wrong ? Do not like to kill it.? picture sitting at the side of my 547 and in use on the calibrator as a first test before adjusting gain and choosing the right probe)

Time to download the manual. Also need to open it because the amplitude changes as I wiggle the connector ( but it was never used and new when I got it)

Fred PA4TIM

Op 5 mrt. 2013 om 21:50 heeft "Craig Sawyers" <c.sawyers@...> het volgende geschreven:

?

> The polystyrene(?) casing of my 134 power supply is cracking up badly, and
I
> fear it won't last a lot longer.
>
> The 230V version of the supply delivers 25.4V to the input of the
(nominal)
> 14V regulator inside the 134 when fed from a UK mains supply (which is
> normally a lot closer to 250V than its nominal 230V would suggest).
>
> If you are looking for an alternative PSU, the Olympus PS-100 photo
printer
> uses a 25V power brick (PS-100 AC1) rated at 1.9A which should be well
more
> than adequate.

Good hint Dave - the grey plastic case of mine is going the way of all dust
too. I just happen to be using it while evaluating noise from a switched
mode supply.

Craig

Mine disappeared while on a trouble call many years ago and I just replaced it
with a 12v 1A wall wart that had a OCV of nearly 20 volts.
It looked fine on the current loop of my 465B so I've used it that way ever since.
This is with a 131 and a P6016 so this may be not be the same thing.

I checked the CH2 output on the back panel and found no waveform with a sinewave coupled to the CH2 input on the front-panel.

However I did note that there were strobes present whenever I toggled CH2 mode or CH2 input coupling switches.

Sounds like the problem could be somewhere in front of the U200?

Regards

Nigel

I found the power brick on eBay ..

Regards,
David Partridge

The polystyrene(?) casing of my 134 power supply is cracking up badly, and

I

fear it won't last a lot longer.

The 230V version of the supply delivers 25.4V to the input of the

(nominal)

14V regulator inside the 134 when fed from a UK mains supply (which is
normally a lot closer to 250V than its nominal 230V would suggest).

If you are looking for an alternative PSU, the Olympus PS-100 photo

printer

uses a 25V power brick (PS-100 AC1) rated at 1.9A which should be well

more

than adequate.

Good hint Dave - the grey plastic case of mine is going the way of all dust
too. I just happen to be using it while evaluating noise from a switched
mode supply.

Craig

The polystyrene(?) casing of my 134 power supply is cracking up badly, and I fear it won't last a lot longer.

The 230V version of the supply delivers 25.4V to the input of the (nominal) 14V regulator inside the 134 when fed from a UK mains supply (which is normally a lot closer to 250V than its nominal 230V would suggest).

If you are looking for an alternative PSU, the Olympus PS-100 photo printer uses a 25V power brick (PS-100 AC1) rated at 1.9A which should be well more than adequate.

HtH
Dave

开云体育

Thanks everyone for the advice.

Where are you located ? I have some .001 mfd @ 6 KV discs.

73, Dick, W1KSZ

The 7A29 and the 7104 use feedbeside circuitry.

John Addis and Bruce Hofer, both at Tektronix, received US patent #4132958
for the feedbeside correction circuit that corrects for the thermal
distortion.
Val Garuts of Tektronix received European patent #EP0324273 for his Wideband
linearized emitter feedback amplifier design utilizing feedbeside
correction.

Dennis

Is there a replacement cap available for the Sprague 430P527 1200pf 4kv? I cannot seem to find one.

Hi Scott,

The manual for the 212 (similar as far as the battery power supply goes)
says
"The batteries act as a large filter capacitor for
the input rectifier in the AC line mode of operation."

If the batteries are dead they don't have the ability to act as a filter
capacitor - their internal resistance will have gone way up, and they won't
be absorbing (and smoothing) the current from the rectifier when the voltage
rises above the battery voltage.

I have run my 214 with dead batteries, no problem. Presumably the dead
batteries were not doing anything for the reasons stated above. On the other
hand I am going to wait to hear from anyone else before I try running mine
without batteries. I'm not entirely convinced by my own arguments that
trying this will not harm my precious little gem of a scope.

Dennis

The P6042 manual says insertion impedance is 0.1R at 5MHz.

The current in the one wire enclosed by the probe will be much lower than the current in the other wires, depending on frequency.
You will also see significant waveform distortion since high frequency components will be diverted more than the low frequency ones. Try it if you do not believe me.

Insertion impedance is often a problem for me, for example if I have parallel capacitors in a SMPS I always measure the total current instead of the current going through individual capacitors, since that would be diminished by the probe impedance. Heisenberg at work, you'll influence the circuit you measure....

The solution is obvious of course, just get enough current probes to put one on each of the parallel wires! ;-)

Please do try to crop old text that is not relevant to your post, especially "daily digest" text.

ST

Thanks to all!

--- In TekScopes@..., David DiGiacomo <daviddigiacomo@...> wrote:

On Tue, Mar 5, 2013 at 7:05 AM, Goran <goran.krusell@...> wrote:

Hi,
in the Tek 465 and many other analog scopes they use resistors to reduce the effect of thermal distortion. For example see Q32 and R37 in the 465 pre-amplifier.

Assume for a moment that R37 is 0 ohm. With no input signal you will have a steady state condition. If you now connect an input signal the operating condition for Q32 will change, its power consumption will change, its chip temperature will change and so will the base emitter voltage drop do. This will create a collector current which is normal signal current plus some temperature induced distortion current.

It can be shown that this effect can be reduced if R37 is given a value such that the R37 power consumption equals the Q32 power consumption in steady state with no input signal. It is reasonable. I buy this.

Now to my question. We got audio amplifier buffs who are prepared to go to any length possible to reach the absolute perfect sound. I have never seen an audio amplifier design where compensation for thermal distortion has been an issue. Has it to do with gain, feedback or bandwidth? Why so, does anyone know?

Douglas Self addresses this in his excellent book, "Audio Power Design
Handbook":

Nonexistent or Negligible Distortions
Having set down what might be called the Eleven Great Distortions, we
must pause to put to flight
a few paper tigers …

...

A third mechanism of very doubtful validity is thermal distortion,
allegedly induced by parameter
changes in semiconductor devices whose instantaneous power dissipation
varies over a cycle. This
would surely manifest itself as a distortion rise at very low
frequencies, but it simply does not
happen. There are several distortion mechanisms that can give a THD
rise at LF, but when these
are eliminated the typical distortion trace remains flat down to at
least 10 Hz. The worst thermal
effects would be expected in Class-B output stages where dissipation
varies wildly over a cycle;
however, drivers and output devices have relatively large junctions
with high thermal inertia. Low
frequencies are of course also where the NFB factor is at its maximum.
This contentious issue is
dealt with at greater length in Chapter 6.

Vertical channel switches in some 7000 series scopes need LF frequency compensation due to internal heating. Quote from the 7854 manual, page 2-37...

"The function of the feedbeside stage is to compensate for low frequency imperfections in the frequency response of the channel switch stage, U75. Self heating of the transistor base emitter junctions in some transistors within U75 causes the low frequency gain to appear larger than the midband gain"

In total there are about six adjustments for each vertical channel to cover the frequency range up to 100kHz. The channel swith LF gain certainly won't change on a cycle by cycle basis.

Chris

John,
Correct, make each wire 5-6 inches long, or longer.


ST,
Yes, the probe reflects an impedance back into the circuit, but that will always happen, so I don't think my suggestion is invalid.
My solution also works for cases where the wire under test is too big for the probe jaws.
Playing with the bucking current won't solve that problem.


HankC, Boston
WA1HOS



________________________________
From: "TekScopes@..." <TekScopes@...>
To: TekScopes@...
Sent: Tuesday, March 5, 2013 7:30 AM
Subject: [TekScopes] Digest Number 7397


All about classic Tektronix CRT o'scopes

All about classic Tektronix CRT o'scopes Group
15 New Messages
Digest #7397

1a
Re: Measure -2450? by "Bob Albert" bob91343
1b
Re: Measure -2450? by "David DiGiacomo" david_digiacomo
1c
Re: Measure -2450? by "Ed Breya" edbreya
1d
Re: Measure -2450? by "Richard Solomon" w1ksz
2a
Re: My new 310A by "maelli01" maelli01
3a
Re: Current rating of P6042 by "HankC" hankc918
3b
Re: Current rating of P6042 by "John Griessen" jgriessen
3c
Re: Current rating of P6042 by "Stefan Trethan" stefan_trethan
4a
Re: 466 Trigger on <1Hz Square Wave? by "Cliff White" kf5iyl
5a
Re: 549 with compresssed trace on right third of screen by "mattko87" mattko87
6a
Re: Tektronix 2465 Ch2 dead by "EnBePe" EnBePe
6b
Tek 214 running without batteries by "Scott Harris" scottrharris
6c
Re: Tektronix 2465 Ch2 dead by "David" david_william_hess
6d
Re: Tek 214 running without batteries by "KeepIt SimpleStupid" KeepItSimpleStupid
7
Does the the PSU of the R7103 without a CRT? by "g_kupka" g_kupka
Messages
1a
Re: Measure -2450?
Mon Mar?4,?2013 11:37?am (PST) . Posted by:
"Bob Albert" bob91343
Take another look.? The Simpson goes to 5000 V and the Triplett to 6000 V.

Bob

--- On Mon, 3/4/13, David DiGiacomo daviddigiacomo@ gmail.com> wrote:

From: David DiGiacomo daviddigiacomo@ gmail.com>
Subject: Re: [TekScopes] Measure -2450?
To: TekScopes@yahoogrou ps.com
Date: Monday, March 4, 2013, 10:27 AM

?

On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert bob91343@yahoo. com> wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it

doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the

values to calculate the result. Most meters go to 1000 V so you need to

divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is

rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use

them to measure 2450V without an external divider? Are you just

counting on the VOM loading to drag the voltage down to something in

range?


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1b
Re: Measure -2450?
Mon Mar?4,?2013 12:38?pm (PST) . Posted by:
"David DiGiacomo" david_digiacomo
Aha, I have a Simpson 260 Series 6, which only goes to 1000V.
Series 1 through 5 had the 5000V ranges.

On Mon, Mar 4, 2013 at 12:37 PM, Bob Albert bob91343@yahoo. com> wrote:

Take another look. The Simpson goes to 5000 V and the Triplett to 6000 V.

Bob


--- On Mon, 3/4/13, David DiGiacomo daviddigiacomo@ gmail.com> wrote:


From: David DiGiacomo daviddigiacomo@ gmail.com>

Subject: Re: [TekScopes] Measure -2450?
To: TekScopes@yahoogrou ps.com
Date: Monday, March 4, 2013, 10:27 AM




On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert bob91343@yahoo. com> wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it
doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the
values to calculate the result. Most meters go to 1000 V so you need to
divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is
rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use
them to measure 2450V without an external divider? Are you just
counting on the VOM loading to drag the voltage down to something in
range?

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1c
Re: Measure -2450?
Mon Mar?4,?2013 1:28?pm (PST) . Posted by:
"Ed Breya" edbreya
I think that some of the old-line classic equipment has evolved into whimpier versions due to cost pressure, fewer HV applications, and mainly product safety requirements and standards.

Ed

--- In TekScopes@yahoogrou ps.com, David DiGiacomo wrote:

Aha, I have a Simpson 260 Series 6, which only goes to 1000V.
Series 1 through 5 had the 5000V ranges.


On Mon, Mar 4, 2013 at 12:37 PM, Bob Albert wrote:

Take another look. The Simpson goes to 5000 V and the Triplett to 6000 V.

Bob


--- On Mon, 3/4/13, David DiGiacomo wrote:


From: David DiGiacomo

Subject: Re: [TekScopes] Measure -2450?
To: TekScopes@yahoogrou ps.com
Date: Monday, March 4, 2013, 10:27 AM




On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert bob91343@... > wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it
doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the
values to calculate the result. Most meters go to 1000 V so you need to
divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is
rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use
them to measure 2450V without an external divider? Are you just
counting on the VOM loading to drag the voltage down to something in
range?

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1d
Re: Measure -2450?
Mon Mar?4,?2013 1:29?pm (PST) . Posted by:
"Richard Solomon" w1ksz
And the lawyers ....

73, Dick, W1KSZ

On Mon, Mar 4, 2013 at 2:28 PM, Ed Breya edbreya@yahoo. com> wrote:

**


I think that some of the old-line classic equipment has evolved into
whimpier versions due to cost pressure, fewer HV applications, and mainly
product safety requirements and standards.

Ed

--- In TekScopes@yahoogrou ps.com, David DiGiacomo wrote:

Aha, I have a Simpson 260 Series 6, which only goes to 1000V.
Series 1 through 5 had the 5000V ranges.


On Mon, Mar 4, 2013 at 12:37 PM, Bob Albert wrote:

Take another look. The Simpson goes to 5000 V and the Triplett to 6000

V.

Bob


--- On Mon, 3/4/13, David DiGiacomo wrote:


From: David DiGiacomo

Subject: Re: [TekScopes] Measure -2450?
To: TekScopes@yahoogrou ps.com
Date: Monday, March 4, 2013, 10:27 AM




On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert bob91343@... > wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it
doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and

measure the

values to calculate the result. Most meters go to 1000 V so you need

to

divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is
rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use
them to measure 2450V without an external divider? Are you just
counting on the VOM loading to drag the voltage down to something in
range?

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2a
Re: My new 310A
Mon Mar?4,?2013 12:19?pm (PST) . Posted by:
"maelli01" maelli01
--- In TekScopes@yahoogrou ps.com, "Steve" wrote:

--- In TekScopes@yahoogrou ps.com, Roland Manser wrote:

Bought a 310A for little money, in perfect condition, optically and
electrically (what a sharp trace!), lucky me.

2 Questions:

It has serial number 013491, rectifier is with silicon diodes.
Anybody has an idea on which year this little oven was built?

Currently the transformer is wired for the "middle" tap. When I measure
my line voltage, it is 230V, with very little variation. Would it make
sense to wire the scope for 240V, to reduce voltage and heat stress?


Roland

This scope model was in production for well over a decade. As mentioned several times in this forum, there is no direct way to determine production date from serial number. These records were never centralized or maintained within Tek. The best way to determine when yours might have been built is to look at the date codes on the electrolytic caps. It is safe to assume that Tek did not carry the inventory long for a higher runner like this, so the scope was probably made within four months or so of the date code.

I have found the filter caps in the 310A to be well over the size needed for maintaining regulation on low line conditions. That probably explains that why the four that I have owned all functioned perfectly with the original caps, being nearly 50 years old. If your nominal line voltage is in the high range, I would try switching to the higher tap. If you have a variac, you could test this first before you make the mod by setting it to the low end of the current range, then measuring the ripple valley of the filter caps to see home much headroom the regulators have. This measurement is easier if you have a differential comparator plug in such as a type W or 7A13.

Steve

Thanks for the hints!
Unmodified, the +300V (found out this is the most critical one) starts showing line frequency dents below 200V on the AC line.
When the line voltage in Switzerland drops to 200V, this will be in the newspaper tomorrow...

So I modified it to 240V line.
Now it needs at least 212V on the line for proper regulation.
And I have a cooler running, energy conscious 310A ;-)
0.75A before, 0.69A after, @230V line

b.t.w -150V supply is at -149.6V, +300V at 297.9V, +100V at 101V, the last owner must have done the calibration right.
Peak to peak ripple on the 300V supply is 35mV.

The large aluminum-housing cap (Sprague) 150uF 250V has 6021 printed on it, could this be 1960, week 21?
A 53 years old electrolytic cap...

Roland


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3a
Re: Current rating of P6042
Mon Mar?4,?2013 2:38?pm (PST) . Posted by:
"HankC" hankc918
Ed,

If you exceed the current rating, the worst that will happen is that the probe may saturate.
The probe will not be damaged; you'll probably have to degauss it though.

You can avoid this by dividing the current that is fed through the probe jaws.
Take a piece of insulated wire (4-6 inches long) & cut it into 5 pieces. Solder them together at both ends.

Feed one length through the probe jaws. The other 4 wires bypass the jaws.

You now have a 5:1 divider.

IIRC, the P6046 must be terminated in 50 ohms at the scope end.

HankC, Boston

WA1HOS

____________ _________ _________ __
From: "TekScopes@yahoogrou ps.com" TekScopes@yahoogrou ps.com>
To: TekScopes@yahoogrou ps.com
Sent: Monday, March 4, 2013 2:00 PM
Subject: [TekScopes] Digest Number 7396


All about classic Tektronix CRT o'scopes

All about classic Tektronix CRT o'scopes Group
15 New Messages
Digest #7396

1a
152-0177-01 tunnel diode for 485. by "Phil Barton" p.barton99
1b
Re: 152-0177-01 tunnel diode for 485. by "Gala Dragos" gala_dragos
1c
Re: 152-0177-01 tunnel diode for 485. by "jerry massengale" hojo3008
2a
Polish 7000 clone on eBleed by widgethunter
2b
Re: Polish 7000 clone on eBleed by "David DiGiacomo" david_digiacomo
3a
Re: Measure -2450? by "anson_williams@ rocketmail. comanson_williams@ rocketmail. com
3b
Re: Measure -2450? by "Rob" doswoodman@ymail. com
3c
Re: Measure -2450? by "Bob Albert" bob91343
3d
Re: Measure -2450? by "David DiGiacomo" david_digiacomo
3e
Re: Measure -2450? by "johncharlesgo rd" johncharlesgord
4a
Re: My new 310A by "Steve" ditter2
5a
Current rating of P6042 by "Alex" snapdiode
5b
Re: Current rating of P6042 by "Brad Thompson" booktronics
5c
Re: Current rating of P6042 by "Ed Breya" edbreya
5d
Re: Current rating of P6042 by "David DiGiacomo" david_digiacomo
Messages
1a
152-0177-01 tunnel diode for 485.
Mon Mar?4,?2013 7:03?am (PST) . Posted by:
"Phil Barton" p.barton99
Looking for Tek 152-0177-01 tunnel diode (10mA and 4pf) for my 485.

Also used in Tek products S53, 067-0587-01, 067-0580-00, 3T5, 3T6, 5S14N,
7D14, 7T11, 7T11A.

Gold DO-17 top hat style. Including postage to the UK.

Phil.

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1b
Re: 152-0177-01 tunnel diode for 485.
Mon Mar?4,?2013 9:31?am (PST) . Posted by:
"Gala Dragos" gala_dragos
Try the 152-0386-0x diode as well, it has 10mA.
--- On Mon, 3/4/13, Phil Barton phil.barton1@ virgin.net> wrote:

From: Phil Barton phil.barton1@ virgin.net>
Subject: [TekScopes] 152-0177-01 tunnel diode for 485.
To: TekScopes@yahoogrou ps.com
Date: Monday, March 4, 2013, 5:02 PM

?

Looking for Tek 152-0177-01 tunnel diode (10mA and 4pf) for my 485.Also used in Tek products S53, 067-0587-01, 067-0580-00, 3T5, 3T6, 5S14N, 7D14, 7T11, 7T11A.Gold DO-17 top hat style. Including postage to the UK.Phil.

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1c
Re: 152-0177-01 tunnel diode for 485.
Mon Mar?4,?2013 9:52?am (PST) . Posted by:
"jerry massengale" hojo3008
Phil,

I have a diode I believe to be a 152-0177-02 which has a bit tighter tolerance. The marking reads 140? It is used but unsoldered. They are precious. $10 plus postage from Texas.

Jerry Massengale

-----Original Message-----
From: Phil Barton phil.barton1@ virgin.net>
To: TekScopes TekScopes@yahoogrou ps.com>
Sent: Mon, Mar 4, 2013 9:03 am
Subject: [TekScopes] 152-0177-01 tunnel diode for 485.

Looking for Tek 152-0177-01 tunnel diode (10mA and 4pf) for my 485.
Also used in Tek products S53, 067-0587-01, 067-0580-00, 3T5, 3T6, 5S14N, 7D14, 7T11, 7T11A.
Gold DO-17 top hat style. Including postage to the UK.
Phil.

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2a
Polish 7000 clone on eBleed
Mon Mar?4,?2013 7:11?am (PST) . Posted by:
widgethunter
ugly and wayyy overpriced - but interesting!
english lettering... .
Bernd

_. com/itm/OFFER- WIN-OSCILLOSCOPE -EMG-TYPE- TR-4658-works- like-
TEKTRONIX-7000- 250MHz-/32108389 2891?pt=BI_ Oscilloscopes&ha sh=item4ac217649 b_

(. com/itm/OFFER- WIN-OSCILLOSCOPE -EMG-TYPE- TR-4658-works- like-TEKTRONIX- 7000-250MHz- /321083892891? pt=BI_Oscillosco pes&hash= item4ac217649b
)
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2b
Re: Polish 7000 clone on eBleed
Mon Mar?4,?2013 9:56?am (PST) . Posted by:
"David DiGiacomo" david_digiacomo
On Mon, Mar 4, 2013 at 8:11 AM, tubesnthings@ aol.com> wrote:

ugly and wayyy overpriced - but interesting!
english lettering... .
Bernd

. com/itm/OFFER- WIN-OSCILLOSCOPE -EMG-TYPE- TR-4658-works- like-TEKTRONIX- 7000-250MHz- /321083892891? pt=BI_Oscillosco pes&hash= item4ac217649b

I think we have discussed these before... they were not Polish... they
were made by EMG in Hungary:

eum.org/r/ elektronik_ oszcilloscope_ tr_4658_155. html

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3a
Re: Measure -2450?
Mon Mar?4,?2013 7:51?am (PST) . Posted by:
"anson_williams@ rocketmail. com" anson_williams@ rocketmail. com
Sorry yes its voltage. Its for testing the high voltage regulator in a 475. I cannot afford another meter or a $100 probe. The voltage divider idea may work.

--- In TekScopes@yahoogrou ps.com, Bob Albert wrote:

Can you be more specific??? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the values to calculate the result.?? Most meters go to 1000 V so you need to divide by maybe 3 or 5.

Bob

















??









Is there a way to take this reading without a 3k meter?

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3b
Re: Measure -2450?
Mon Mar?4,?2013 10:09?am (PST) . Posted by:
"Rob" doswoodman@ymail. com

I don't really see why an 80K-40 wouldn't be useful in the same

application
that the 80K-15 was made for<<< <<

Obviously it's because the yellow one came in the box with the air cleaner..
hence the name *smile *.

The red ones are called "High Voltage Probe for anything but Air Cleaner
Prober Probes." ..

Hopefully taken in the spirit intended.

Rob

From: TekScopes@yahoogrou ps.com [mailto:TekScopes@ yahoogrou ps.com] On Behalf
Of J. L. Trantham
Sent: Monday, March 04, 2013 7:20 AM
To: TekScopes@yahoogrou ps.com
Subject: RE: [TekScopes] Measure -2450?

It's the same size as the 80K-40, yellow instead of red, has the same 1 GOhm
input impedance when used with a 10 MOhm input meter, but rated only for 15
KV instead of 40 KV.

I don't really see why an 80K-40 wouldn't be useful in the same application
that the 80K-15 was made for. Or perhaps the 80K-40 came later with higher
rated insulation to 40 KV?

Joe

-----Original Message-----
From: TekScopes@yahoogrou ps.com
[mailto:TekScopes@ yahoogrou ps.com ] On
Behalf
Of Mark Wendt
Sent: Monday, March 04, 2013 4:25 AM
To: TekScopes@yahoogrou ps.com
Subject: Re: [TekScopes] Measure -2450?

On 03/04/2013 01:13 AM, David wrote:

Fluke 80K-6 high voltage probes are inexpensive used and good to 6
kilovolts. They are designed to be used with a 10 megohm input
resistance multimeter which is standard. They only have 75 megohms of
input resistance though which may be a problem measuring many of the
CRT voltages like the grid or focus but will work fine for measuring
the cathode voltage which is regulated.

I knew probes could be used for a lot of things, but this is a new one on
me:

. com/itm/FLUKE- 80K-15-Electroni c-Air-Cleaner- Probe-/31041859
5539>

Mark

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Re: Measure -2450?
Mon Mar?4,?2013 10:22?am (PST) . Posted by:
"Bob Albert" bob91343
Maybe you can't afford another meter, but the old Simpson or Triplett units go for low prices at swap meets.? Occasionally an old timer will give you one.? They are very useful and even in this modern day there will be situations where they do a better job.

The main limitation is accuracy, and on low voltage ranges, the burden.? Excellent for continuity, diode test, etc. which will be much faster with one of those.? I can check a row of 20 diodes with a VOM in maybe 8 or 10 seconds; try that on your DVM.

Bob

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Re: Measure -2450?
Mon Mar?4,?2013 10:27?am (PST) . Posted by:
"David DiGiacomo" david_digiacomo
On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert bob91343@yahoo. com> wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it
doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the
values to calculate the result. Most meters go to 1000 V so you need to
divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is
rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use
them to measure 2450V without an external divider? Are you just
counting on the VOM loading to drag the voltage down to something in
range?

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Re: Measure -2450?
Mon Mar?4,?2013 10:59?am (PST) . Posted by:
"johncharlesgo rd" johncharlesgord
Some of the earlier Triplett 630 models went to 5kV or 6kV. The more recent 630NA and 630NS are only to 1200V.

--John Gord

--- In TekScopes@yahoogrou ps.com, David DiGiacomo wrote:

On Sun, Mar 3, 2013 at 9:55 PM, Bob Albert wrote:

Can you be more specific? Are you measuring voltage?

If so, an ordinary Simpson 260 or Triplett 630 will do, as long as it
doesn't need to be very accurate.

If you need precision you can cobble up a voltage divider and measure the
values to calculate the result. Most meters go to 1000 V so you need to
divide by maybe 3 or 5.

Bob, what are you saying here? As far as I know, the Simpson 260 is
rated to 1000VDC and the Triplett 630 to 1200VDC. How would you use
them to measure 2450V without an external divider? Are you just
counting on the VOM loading to drag the voltage down to something in
range?

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Re: My new 310A
Mon Mar?4,?2013 8:23?am (PST) . Posted by:
"Steve" ditter2
--- In TekScopes@yahoogrou ps.com, Roland Manser wrote:

Bought a 310A for little money, in perfect condition, optically and
electrically (what a sharp trace!), lucky me.

2 Questions:

It has serial number 013491, rectifier is with silicon diodes.
Anybody has an idea on which year this little oven was built?

Currently the transformer is wired for the "middle" tap. When I measure
my line voltage, it is 230V, with very little variation. Would it make
sense to wire the scope for 240V, to reduce voltage and heat stress?


Roland

This scope model was in production for well over a decade. As mentioned several times in this forum, there is no direct way to determine production date from serial number. These records were never centralized or maintained within Tek. The best way to determine when yours might have been built is to look at the date codes on the electrolytic caps. It is safe to assume that Tek did not carry the inventory long for a higher runner like this, so the scope was probably made within four months or so of the date code.

I have found the filter caps in the 310A to be well over the size needed for maintaining regulation on low line conditions. That probably explains that why the four that I have owned all functioned perfectly with the original caps, being nearly 50 years old. If your nominal line voltage is in the high range, I would try switching to the higher tap. If you have a variac, you could test this first before you make the mod by setting it to the low end of the current range, then measuring the ripple valley of the filter caps to see home much headroom the regulators have. This measurement is easier if you have a differential comparator plug in such as a type W or 7A13.

Steve

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Current rating of P6042
Mon Mar?4,?2013 8:48?am (PST) . Posted by:
"Alex" snapdiode
I think we all know intuitively what happens if a voltage rating is exceeded on a probe or just in general: Bzzt and maybe poof!

But what happens if you exceed the current rating of a P6042? It's rated at 20A up to 1MHz, I'm working on a project with a 40A rectifier.

Will there be permanent damage to the probe? (If I can even get 40A through a wire small enough to fit the probe).

I'll probably end up using a shunt but it might still be possible to get a malfunction current way higher than 40A at the start of this project.

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Re: Current rating of P6042
Mon Mar?4,?2013 9:09?am (PST) . Posted by:
"Brad Thompson" booktronics
On 3/4/2013 11:48 AM, Alex wrote:

I think we all know intuitively what happens if a voltage rating is
exceeded on a probe or just in general: Bzzt and maybe poof!

But what happens if you exceed the current rating of a P6042? It's rated
at 20A up to 1MHz, I'm working on a project with a 40A rectifier.

Will there be permanent damage to the probe? (If I can even get 40A
through a wire small enough to fit the probe).

I'll probably end up using a shunt but it might still be possible to get
a malfunction current way higher than 40A at the start of this project.

Hello--

It's possible that running a current probe over its rating would
result in semipermanent magnetism of the core. You'd then need to
demagnetize the core by running gradually-decreasin g AC
through it (thinking of a filament transformer w/a resistive load
fed from a Variac). I've never encountered the problem,
so I'm hoping that someone else will comment.

You can fake a current shunt by connecting several wires of
equal length in parallel. Clamp onto one wire and measure
the current. Then multiply the measurement by the number
of wires in the bundle.

73--

Brad AA1IP

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Re: Current rating of P6042
Mon Mar?4,?2013 9:28?am (PST) . Posted by:
"Ed Breya" edbreya
If your 40A is at line frequency or SMPS frequencies like 20-100 kHz, it should be no problem - the linearity and accuracy will suffer, but there shouldn' t be much power dissipation when occasionally exceeding the specs.

Of course, there must be some current/frequency level that will cause damage due to overheating the secondary windings or the core, making things melt. The frequency will be most important since it causes the power induction. Picture the situation at DC - no matter how much current you shove through the link, the core will saturate, so no more signal will be induced into the secondary windings. Only the power dissipation in the link itself can generate enough heat to melt things around it. The Hall elements on DC probes are also protected by core saturation.

As frequency goes up, the problem becomes heat from the power dissipation in the windings and from core loss. When the frequency gets high enough, the core doesn't matter any more - everything will heat up from the RF current. Also, single pulses that are extremely large can damage things - but that's true with anything.

Ed

--- In TekScopes@yahoogrou ps.com, "Alex" wrote:

I think we all know intuitively what happens if a voltage rating is exceeded on a probe or just in general: Bzzt and maybe poof!

But what happens if you exceed the current rating of a P6042? It's rated at 20A up to 1MHz, I'm working on a project with a 40A rectifier.

Will there be permanent damage to the probe? (If I can even get 40A through a wire small enough to fit the probe).

I'll probably end up using a shunt but it might still be possible to get a malfunction current way higher than 40A at the start of this project.

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Re: Current rating of P6042
Mon Mar?4,?2013 10:23?am (PST) . Posted by:
"David DiGiacomo" david_digiacomo
I'm not sure if this affects the OP, but it's worth considering that
Tek AC/DC current probes like the P6042 don't do the DC measurement in
the obvious open-loop way. Instead, the sense winding is driven with
DC current to hold the net DC flux at zero. If you peg the DC amp
with a large startup current, the core will get magnetized and then
you won't get accurate measurements until you degauss it.

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Re: Current rating of P6042
Mon Mar?4,?2013 4:26?pm (PST) . Posted by:
"John Griessen" jgriessen
On 03/04/2013 04:31 PM, HankC wrote:

Take a piece of insulated wire (4-6 inches long) & cut it into 5 pieces. Solder them together at both ends.
Feed one length through the probe jaws. The other 4 wires bypass the jaws.
You now have a 5:1 divider.

I imagine you meant 5 pcs 6 inches long.

The longer the better really, so the slightly random solder blobs at the ends don't affect the
length of any one wire much in relation to the total length of the path
through that one wire.


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Re: Current rating of P6042
Tue Mar?5,?2013 2:00?am (PST) . Posted by:
"Stefan Trethan" stefan_trethan
Actually, I don't think this idea will work at all well!
The current probes insert quite some impedance into the wire they are
clipped on, so current distribution will no longer be equal.

What you can do is extend the DC bucking range by threading a second
wire through the core and biasing it with a DC current.
There is a Tek appnote somewhere.

ST

On Tue, Mar 5, 2013 at 1:26 AM, John Griessen john@ecosensory. com> wrote:

On 03/04/2013 04:31 PM, HankC wrote:

Take a piece of insulated wire (4-6 inches long) & cut it into 5 pieces. Solder them together at both ends.
Feed one length through the probe jaws. The other 4 wires bypass the jaws.
You now have a 5:1 divider.

I imagine you meant 5 pcs 6 inches long.

The longer the better really, so the slightly random solder blobs at the ends don't affect the
length of any one wire much in relation to the total length of the path
through that one wire.

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4a
Re: 466 Trigger on <1Hz Square Wave?
Mon Mar?4,?2013 4:30?pm (PST) . Posted by:
"Cliff White" kf5iyl
I'm not sure what I did differently, but it's now working! Thanks guys!

-Cliff

On 03/02/2013 02:02 PM, Denis wrote:

Cliff,
It sounds like your trigger point is close to the baseline and
triggering on noise.
Here is a round about way to set the trigger point, assuming that
your 5V p-p signal will fill most of the screen:
Set Storage to Normal (Non-Storage)
Set Horiz sweep to "A"
Set Sweep to "Auto" mode
Set Time/Div to "1mS"
Set Trigger Coupling to "DC"
Setup Ch1 to show trace at mid screen with input "Gnd"
Rotate Pos control and watch A Swp Trig'd light flash at the sweep
trigger point
Adjust the A Sweep Trigger "Level" control so the trigger point occurs
about half way up your waveform
Now reset Ch1 to show your signal swinging below and above the mid line
Set Sweep to "Norm Trig"
Walk the Time/Div to longer sweeps so you can observe the leading edge
of your signal
You may have to change Trigger Polarity (and readjust the trigger
level) to observe the portion of the signal of interest
Set the Time/Div as required
Denis K

*From:* Cliff White cn.white@sunbelt- plb.com>
*To:* TekScopes@yahoogrou ps.com
*Sent:* Saturday, March 2, 2013 11:04 AM
*Subject:* Re: [TekScopes] 466 Trigger on <1Hz Square Wave?
I have it set to normal mode, I've tried both AC, DC, and HF reject
couplings, and the channel itself is coupled DC. But it still seems to
only want to trigger on the little bit of ripple on the wave, and not
actually the signal itself.

On 03/02/2013 12:12 AM, David wrote:

You can absolutely trigger on low frequency signals including slow
ramps. Be sure to set TRIG MODE (below the time/div control on the
right side) to NORM instead of AUTO to prevent the sweep from free
running when the triggers occur slower than about 20 Hz.

You may need to use DC input coupling and DC trigger coupling.

On Fri, 01 Mar 2013 22:12:46 -0600, Cliff White
mailto:cn.white@sunbelt- plb.com wrote:

I have a case where I need to use my 466 to view a /very/ slow (less
than one Hertz) 5 volt p-p square wave. Is it possible and/or easy to
make it trigger on such a signal? By using the storage mode I can make
it easily viewable, and stay on the screen until the next sweep, I just
can't seem to make it reliably trigger. Ideas?

-Cliff

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Re: 549 with compresssed trace on right third of screen
Mon Mar?4,?2013 9:44?pm (PST) . Posted by:
"mattko87" mattko87
Hi Max

Interessing, because i living in germany and have many nederslands- Tektronix and few Guernsey in collection. Guernsey is very similar with Portland. Sprangue 160P, and Goodwill capicator, while nederslands- tek has only EROmet and EROfol II. I havn?t seeing american capicator (but ceramic, yes) in NL-Tektronix.

Best regards

--- In TekScopes@yahoogrou ps.com, "Max Mazza" wrote:

I had a similar problem recently with Aerovox caps in my 564: one of these was defective, causing malfunction when erasing the storage screen.
After some checks, the only culprit was a 0.1uF 600V Aerovox capacitor. I don't have any ESR meter, but examining the erasure pulse with another scope, I immediately realized that the capacitor was lossy. I think ESR was fine, buth the dielectric absorption not.

On the component list, the caps was specified as metallized polyester.
I've temporarily replaced the defective one with two capacitor 0.1uF 630V ceramic FACON in parallel to compensate for major losses in ceramic type, waiting to have the right polyester type.

Oddly enough, since Matt states that only 549 Portland scopes used Areovox caps, my 564 is from Heerenveen, Netherlands.

Max


--- In TekScopes@yahoogrou ps.com, "mattko87" ; wrote:

Sorry, my fault.

0,5?F , (C335), that is right.

Heerenveen 549 has EROmet capicator, germany capicator.
But, Portland 549 has bad black areovox, replaced him and 549 run fine.

Best regards
Matt

--- In TekScopes@yahoogrou ps.com, "mattko87" ; wrote:

Hi

pleas replaced 0,33?F Areovox capicator in Horz. amplifier.
This capicator ist bad.

I has repaired many 549, one from Nethersland (Heerenveen) has not this Problem, but Portland-549 has this problem awalys.

Best regards
matt

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6a
Re: Tektronix 2465 Ch2 dead
Tue Mar?5,?2013 1:26?am (PST) . Posted by:
"EnBePe" EnBePe
This is interesting. I've got a 2445 which has CH2 missing; in this case the horizontal CH2 trace is completely missing, not just the waveform display..... is this the same issue or something different?

Nigel

--- In TekScopes@yahoogrou ps.com, David wrote:

The outputs from the U140 and U150 shift registers control more than
the attenuator relays. The outputs can change after the relays are
activated by the strobe signal from U130G without affecting the
relays. (I am going by the 2465B schematic which I have a nice copy
of.)

If you have an analog or digital storage oscilloscope, you could
trigger it on the relay strobe signal while watching the different
outputs of U140 and U150 to see if they match.

I would check the coil resistance of each relay and make sure they are
all good but I suspect you will find that the problem is inside of the
attenuator assembly.

On Sat, 02 Mar 2013 20:42:28 -0000, "J_O" wrote:

Hi Guys !
I need a little help to fix my scope.
Ch1 is working fine, diagnostics is OK.
No signal comes out Ch2 attenuators - testpoint 11
If I set the input attenuators to 1V/Div and compare U140 and U150 pinouts I see differences. Should they be the same for swiching the same relays?
On front panel all swiches indicate the same, I hear clicks at the same time if rotating V/Div knob.

Your help is much apreciated
Joe

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Tek 214 running without batteries
Tue Mar?5,?2013 1:54?am (PST) . Posted by:
"Scott Harris" scottrharris
I tried to run my Tek 214 with the batteries removed. Is it likely that I damaged anything?

I searched the archives _after_ I removed the batteries and turned the scope on and found that the batteries are required to be in the circuit for the scope to work.

Both packs are shot, so I've ordered replacement cells to rebuild them. The scope worked fine the last time I tried to use it, but after being stored for a while, the cells won't take a charge.

Once I get the new cells, I'll rebuild the packs, cross my fingers, and see if I can get it to working again.

Thanks,
-Scott

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Re: Tektronix 2465 Ch2 dead
Tue Mar?5,?2013 4:21?am (PST) . Posted by:
"David" david_william_hess
The trace might be positioned off of the CRT because of a severe
vertical offset. I would check the inputs at the channel switch.

On Tue, 05 Mar 2013 09:26:27 -0000, "EnBePe"
nigel-pritchard@ o2.co.uk> wrote:

This is interesting. I've got a 2445 which has CH2 missing; in this case the horizontal CH2 trace is completely missing, not just the waveform display..... is this the same issue or something different?

Nigel

--- In TekScopes@yahoogrou ps.com, David wrote:

The outputs from the U140 and U150 shift registers control more than
the attenuator relays. The outputs can change after the relays are
activated by the strobe signal from U130G without affecting the
relays. (I am going by the 2465B schematic which I have a nice copy
of.)

If you have an analog or digital storage oscilloscope, you could
trigger it on the relay strobe signal while watching the different
outputs of U140 and U150 to see if they match.

I would check the coil resistance of each relay and make sure they are
all good but I suspect you will find that the problem is inside of the
attenuator assembly.

On Sat, 02 Mar 2013 20:42:28 -0000, "J_O" wrote:

Hi Guys !
I need a little help to fix my scope.
Ch1 is working fine, diagnostics is OK.
No signal comes out Ch2 attenuators - testpoint 11
If I set the input attenuators to 1V/Div and compare U140 and U150 pinouts I see differences. Should they be the same for swiching the same relays?
On front panel all swiches indicate the same, I hear clicks at the same time if rotating V/Div knob.

Your help is much apreciated
Joe

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6d
Re: Tek 214 running without batteries
Tue Mar?5,?2013 4:30?am (PST) . Posted by:
"KeepIt SimpleStupid" KeepItSimpleStupid
Scott:

The 212 isn't damaged when you run w/o batteries, so I doubt the 214 is.? It looks like it takes the same battery set.? I got the packs already made up (no connectors) from www.bulbtronics. com for $14.02/pack USD back in 2010.

--- On Tue, 3/5/13, Scott Harris scottrharris@ gmail.com> wrote:

From: Scott Harris scottrharris@ gmail.com>
Subject: [TekScopes] Tek 214 running without batteries
To: TekScopes@yahoogrou ps.com
Date: Tuesday, March 5, 2013, 4:55 AM

?

I tried to run my Tek 214 with the batteries removed. Is it likely that I damaged anything?


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Does the the PSU of the R7103 without a CRT?
Tue Mar?5,?2013 4:14?am (PST) . Posted by:
"g_kupka" g_kupka
I have a R7103 mainframe without CRT.
Now I can get a CRT for the R7103. But before I buy the CRT I will check whether mainframe is ok. And there my question:
Will the PSU run without a CRT?
Gerhard


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On Tue, Mar 5, 2013 at 7:05 AM, Goran <goran.krusell@...> wrote:

Hi,
in the Tek 465 and many other analog scopes they use resistors to reduce the effect of thermal distortion. For example see Q32 and R37 in the 465 pre-amplifier.

Assume for a moment that R37 is 0 ohm. With no input signal you will have a steady state condition. If you now connect an input signal the operating condition for Q32 will change, its power consumption will change, its chip temperature will change and so will the base emitter voltage drop do. This will create a collector current which is normal signal current plus some temperature induced distortion current.

It can be shown that this effect can be reduced if R37 is given a value such that the R37 power consumption equals the Q32 power consumption in steady state with no input signal. It is reasonable. I buy this.

Now to my question. We got audio amplifier buffs who are prepared to go to any length possible to reach the absolute perfect sound. I have never seen an audio amplifier design where compensation for thermal distortion has been an issue. Has it to do with gain, feedback or bandwidth? Why so, does anyone know?

Douglas Self addresses this in his excellent book, "Audio Power Design
Handbook":

Nonexistent or Negligible Distortions
Having set down what might be called the Eleven Great Distortions, we
must pause to put to flight
a few paper tigers …

...

A third mechanism of very doubtful validity is thermal distortion,
allegedly induced by parameter
changes in semiconductor devices whose instantaneous power dissipation
varies over a cycle. This
would surely manifest itself as a distortion rise at very low
frequencies, but it simply does not
happen. There are several distortion mechanisms that can give a THD
rise at LF, but when these
are eliminated the typical distortion trace remains flat down to at
least 10 Hz. The worst thermal
effects would be expected in Class-B output stages where dissipation
varies wildly over a cycle;
however, drivers and output devices have relatively large junctions
with high thermal inertia. Low
frequencies are of course also where the NFB factor is at its maximum.
This contentious issue is
dealt with at greater length in Chapter 6.

开云体育

I think you would need to insulate the high voltage lead that normally plugs into the ultor on the tube side. I think it has about 24 kV on it, that will jump across a considerable gap. It will need something more than just a bit of insulation tape wrapped around it. Perhaps some plastic tubing over the end, then put the end in a glass jar and keep it away from the chassis, circuitry, etc. This is close to the final voltage in a CRT color TV set. There is also a couple of kV at the tube socket so keep that clear of anything too.

Don Black.

On 06-Mar-13 1:57 AM, jerry massengale wrote:

Sorry, the title was wrong.
The right title is:

Does the PSU of the R7103 run without a CRT?

Gerhard