Did you do the grid bias adjustment in the service manual?
?
?
Tom
?
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----- Original Message -----
Sent: Saturday, October 27, 2012 4:25
PM
Subject: [TekScopes] 2215 trace
intensity
?
The maximum intensity of the trace on my 2215 is very low. It makes
impossible to use the delayed time base.
I have checked the power supplies,
2KV and 8 KV are OK.
Does somebody have some idea for this
issue?
|
Re: Question about JIS fasteners
Thanks for the detailed investigation.
I'm not really any further than before. Some of my screws do not fit a
new phillips driver well, others fit perfectly.
Not all of those which don't fit well have the dot. They also don't
fit any other driver (pozi, other phillips sizes).
A phillips 1 with the tip shortened does fit better than a phillips 2
on some of them.
The description of a smaller web (smaller radius) seems plausible
looking at how the misfitting screws interfere with the driver.
I have one cheap bit that is ground with virtually no radius and it
goes in further, but is not perfect, either because the angles are not
right or simply because it is a cheap bad bit.
There definitely is a standard for camera screws, JCIS 8-70, which is
different from phillips and seems to be used mostly for smaller
screws. I was unable so far to find the standard itself or reliable
drawings.
<>
In case you are wondering, no I'm not obsessed, not much anyway.
ST
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On Sat, Oct 27, 2012 at 9:24 PM, Tom Jobe <tomjobe@...> wrote: I heard back from another retired Honda person on this question about the
JIS vs. ISO vs. Phillips question.
Apparently the Honda screws with the single dot on them are the ones that
have the newer ISO thread combination, and the older screws with the JIS
thread combination have no dot on them. This is reported here:
As far as any of us know the shape of the "+" recess in the head of the
screws did not change when they made the change to ISO threads beginning in
1967.
The friend who is the most knowledgeable of the three of us, thinks that all
of the Honda screws have the JIS variation of the Phillips shape in the
screw heads.
This friend worked on a problem situation years ago where removing some
Honda screws was very difficult out in the field, and the best solution they
found was this Snap-on driver bit. These Phillips "ACR" driver bits
completely solved the problem they were having.
The picture on this web page shows you the "teeth" they put on these Snap-on
"ACR" driver bits, and this link is for the #1 size driver bit.
Thinking back on things that happened using the Honda screws, I remember
having to grind the sharp point off of Phillips screw drivers to get them to
fit better in the Honda screws, which helps support the idea that the screws
are in fact JIS, and not a true Phillips shaped recess.
I have a new set of Kowa brand "T" handle screw drivers and sockets. They
are the ones often used in Japanese motorcycle maintenance, and I assume
that they are whatever is used in Japan (JIS or Phillips?). When you compare
the Kowa screwdriver tips with nice Snap-on screwdriver tips there is not
much difference. I will take a closer look and get some measurements and
pictures of them.
tom jobe...
PS A little later, a close look at the Kowa screwdrivers and some nice old
Snap-on Phillips screwdrivers shows no functional difference. The Kowa tools
being new seem to "grab" the Honda screws a little better, but only because
the old Snap-on tools are worn a bit smoother from use.
I'm still amazed at how well the new Pozidriv screwdriver works in the old
Tektronix Posidriv screws!
----- Original Message -----
From: "Tom Jobe" <tomjobe@...>
To: "TekScopes" <TekScopes@...>
Sent: Friday, October 26, 2012 4:01 PM
Subject: Fw: Question about JIS fasteners
Below is the first reply I got from a knowledgeable Honda friend.
The link he included explains the thread pitch issues between the older
JIS and the newer ISO thread standards.
He doesn't believe there is a difference where the screw driver goes into
the screw, between JIS and ISO.
tom jobe...
As far as the Honda thing goes, this is what i believe
I haven't really looked at phillips head screws lately.
For sure, during the late 60's and thru the 70's, this was the rule-
JIS and ISO used different thread standards.
The JIS screw heads were unmarked.
The ISO heads had a punch mark.
I never read about the "+" being different from one another. (where the
tool fits)
The JIS were supposed to have stopped being spec'ed on Honda machines
around the late 60's or, early 70's, so i didn't hardly worry about this
situation because the earliest bike i worked on (for real, not just a
flat
tire deal) was a 1969 and i'm pretty sure it was ISO by then.
I thought i would check this with the world
Take a look at this site
------------------------------------
Yahoo! Groups Links
|
The maximum intensity of the trace on my 2215 is very low. It makes impossible to use the delayed time base.
I have checked the power supplies, 2KV and 8 KV are OK.
Does somebody have some idea for this issue?
|
Re: Question about JIS fasteners
I heard back from another retired Honda person on this question about the JIS vs. ISO vs. Phillips question.
Apparently the Honda screws with the single dot on them are the ones that have the newer ISO thread combination, and the older screws with the JIS thread combination have no dot on them. This is reported here:
As far as any of us know the shape of the "+" recess in the head of the screws did not change when they made the change to ISO threads beginning in 1967.
The friend who is the most knowledgeable of the three of us, thinks that all of the Honda screws have the JIS variation of the Phillips shape in the screw heads.
This friend worked on a problem situation years ago where removing some Honda screws was very difficult out in the field, and the best solution they found was this Snap-on driver bit. These Phillips "ACR" driver bits completely solved the problem they were having.
The picture on this web page shows you the "teeth" they put on these Snap-on "ACR" driver bits, and this link is for the #1 size driver bit.
Thinking back on things that happened using the Honda screws, I remember having to grind the sharp point off of Phillips screw drivers to get them to fit better in the Honda screws, which helps support the idea that the screws are in fact JIS, and not a true Phillips shaped recess.
I have a new set of Kowa brand "T" handle screw drivers and sockets. They are the ones often used in Japanese motorcycle maintenance, and I assume that they are whatever is used in Japan (JIS or Phillips?). When you compare the Kowa screwdriver tips with nice Snap-on screwdriver tips there is not much difference. I will take a closer look and get some measurements and pictures of them.
tom jobe...
PS A little later, a close look at the Kowa screwdrivers and some nice old Snap-on Phillips screwdrivers shows no functional difference. The Kowa tools being new seem to "grab" the Honda screws a little better, but only because the old Snap-on tools are worn a bit smoother from use.
I'm still amazed at how well the new Pozidriv screwdriver works in the old Tektronix Posidriv screws!
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----- Original Message ----- From: "Tom Jobe" <tomjobe@...> To: "TekScopes" <TekScopes@...> Sent: Friday, October 26, 2012 4:01 PM Subject: Fw: Question about JIS fasteners Below is the first reply I got from a knowledgeable Honda friend.
The link he included explains the thread pitch issues between the older JIS and the newer ISO thread standards.
He doesn't believe there is a difference where the screw driver goes into the screw, between JIS and ISO.
tom jobe...
As far as the Honda thing goes, this is what i believe
I haven't really looked at phillips head screws lately.
For sure, during the late 60's and thru the 70's, this was the rule-
JIS and ISO used different thread standards.
The JIS screw heads were unmarked.
The ISO heads had a punch mark.
I never read about the "+" being different from one another. (where the
tool fits)
The JIS were supposed to have stopped being spec'ed on Honda machines
around the late 60's or, early 70's, so i didn't hardly worry about this
situation because the earliest bike i worked on (for real, not just a flat
tire deal) was a 1969 and i'm pretty sure it was ISO by then.
I thought i would check this with the world
Take a look at this site
|
Hi David,
It's difficult to say which LV regulator is responsible, assuming that it's not a combination of effects. You might be right about those -50V and -15V regulators. Specifically the -15V regulator output is the most sensitive for a "pencil touch" at the bases of the comparator transistor pair.
Today I checked a supply that worked well previously without sense lines. The same oscillation appears. So I think it's the geometry of my new spider web in combination with bad high frequency characteristics of the 10 W and 5 W resistors.
For the moment I leave this issue for what it is since I'm attacking problems too much on a FILO basis.
Albert
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--- In TekScopes@..., David <davidwhess@...> wrote:
The capacitors should be more important than the sense lines. They
provide part of each regulator's frequency and phase compensation.
I would be suspicious if not hooking up the sense lines has an effect.
They are all shunted to the main lines via low value resistors from 47
to 470 ohms. Could one or more of those resistors be partially open?
Or maybe the pole-zero compensation in one of the regulators (resistor
and capacitor in series like R3278/C3278 and R3289/C3289 in the -15
volt regulator) is bad.
The -15 and -50 volt regulators are more liable to oscillate because
their NPN output power stages have gain. They have extra frequency
compensation of their output stages to help control that.
|
Re: Tek 494P spectrum analyzer
It's right under the "REFERENCE LEVEL" label.
See photo:
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On Sat, Oct 27, 2012 at 3:57 AM, Asadullah <mirasad31415@...> wrote: And to add to my misery, the Om describes a procedure which is initiated by pressing <SHIFT> <CAL>
I have searched high and low but can not find the <CAL> button.
This is driving up the wall and over the top.
Please some body help.
|
Re: 565 with 3a9 plugins on eBay- Kirkland WA
Oh man I don't need another scope, yet I'm driving up to Seattle tomorrow to pick up one. It's not one of these :-(
Bill Higdon
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--- In TekScopes@..., "bob98033" <bob98033@...> wrote:
I am the seller of the scope. This 565 along with two others to be listed later this week are from a lot purchased from University of Washington auction. Two years ago I purchased a similiar lot of four 565's from the University but these three are in much better condition and are marked on the front "keeper 2010". I suspect these will be the last 565's I will get because in the lot extra plugins and SPARE PARTS wre included. The list of spare parts include CRT's, timebase assemblies,high voltage transforer,etc basically everything you need to bring back a "dud" 565. After I checked,repair and verify calibration of the other two 565's I will put all the spare parts up for sale in lot, the extra plugins in another lot.
bob
P.S. Anyone need 600 MHZ Tektronix pulse generator? I have one listed on ebay...It was part of the same lot along with a bunch of other Tektronix stuff to be sorted through.
|
Can you get a dot on screen in X-Y mode ? This mode is a little tricky to set up; do you have the manual ? HankC, Boston
|
Hi,
Does someone have a junk 7704A that powers up okay? One with a bad CRT would work. I cannot pay much more than shipping to Central Texas, 76501(Temple area). Please respond off list.
Jerry Massengale
|
Re: Tek 494P spectrum analyzer
And to add to my misery, the Om describes a procedure which is initiated by pressing <SHIFT> <CAL>
I have searched high and low but can not find the <CAL> button.
This is driving up the wall and over the top.
Please some body help.
|
Re: Help with a Tek 575 Curve tracer
The curve tracer seems to work, but the out and back I-V curves do not lie on top of each other and the whole family of I-V curves seems to "wobble" a bit on the screen.
Does this sound familiar? Any ideas? That sounds about right. It depends on the collector base capacitance, but you can end up with "looping" where this capacitance has a significant effect, particularly with medium to high power transistors. In fact Tek recommended a method for estimating this capacitance; you add external capacitance and when the loop doubles, the external value about equals the collector base capacitance. The wobble is mainly visual - if you reduce the number of base steps, you will see that the wobble disappears every other step. Also switch to the higher step generator rate to reduce trace flicker. Craig
|
Re: Help with a Tek 575 Curve tracer - Volts/Step adjustment
One other issue is that when I try and set the VOLTS/STEP ADJ according to the procedure on page 5-4 of the manual, I can only get 2 traces per major division with the pot turned all the way clockwise. I.e. it appears that the volts/step is half of what it should be. The vertical traces line up with the major divisions AND the halfway point between the divisions.
Scoping the base pin confirms that I'm getting 5 mV/step on the base instead of 10 mV. In addition, the base steps start below zero no matter how I adjust step zero on the front panel. This is odd because I thought I had just completed step 11 where the step zero is adjusted.
Any ideas on what to check next?
Thanks,
-Scott
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On Oct 27, 2012, at 1:34 AM, Scott Harris <scottrharris@...> wrote: I've checked and replaced a few caps in the -150V, 100V, and 300V supplies in my Tek 575.
Now these supplies are all in spec for voltage and ripple. One cap seems to have an elevated ESR, so I'll probably replace it soon too.
I've also replaced all four 2000 uF caps in the 12 V supply. The 150 uF cap in this section seems to be OK. What voltages and ripple should I expect here? I didn't see any specs on the schematic.
The curve tracer seems to work, but the out and back I-V curves do not lie on top of each other and the whole family of I-V curves seems to "wobble" a bit on the screen.
Does this sound familiar? Any ideas?
I'm wondering if I have some excessive ripple somewhere else. Any ideas?
I'll try and make a YouTube video, to demonstrate what I'm talking about.
Thanks,
-Scott
|
Help with a Tek 575 Curve tracer
I've checked and replaced a few caps in the -150V, 100V, and 300V supplies in my Tek 575.
Now these supplies are all in spec for voltage and ripple. One cap seems to have an elevated ESR, so I'll probably replace it soon too.
I've also replaced all four 2000 uF caps in the 12 V supply. The 150 uF cap in this section seems to be OK. What voltages and ripple should I expect here? I didn't see any specs on the schematic.
The curve tracer seems to work, but the out and back I-V curves do not lie on top of each other and the whole family of I-V curves seems to "wobble" a bit on the screen.
Does this sound familiar? Any ideas?
I'm wondering if I have some excessive ripple somewhere else. Any ideas?
I'll try and make a YouTube video, to demonstrate what I'm talking about.
Thanks,
-Scott
|
Re: 7000 series on-screen displays boards
If you mean the PCB assembly to scope cross-reference, there are at least two versions, one of which should be in Tekscope's files or one of the other Tek repositories.
-Dave
From: "David" To: TekScopes@... Sent: Friday, October 26, 2012 8:58:10 PM Subject: Re: [TekScopes] 7000 series on-screen displays boards
?
Of the three different readout boards that I now know of now, the 7844
uses the common one so it will be the easiest to find as it is on the
less expensive 7000 series mainframes.
I am surprised there is not already a list for this somewhere.
On Fri, 26 Oct 2012 23:50:04 -0400, Michael Dunn <md@...>
wrote:
> Thanks for all the info. I have a couple of 7844s in need of
>repair, so may end up with one working unit, and a display board
>donor...?
>
>Michael
|
Re: 7000 series on-screen displays boards
Of the three different readout boards that I now know of now, the 7844 uses the common one so it will be the easiest to find as it is on the less expensive 7000 series mainframes. I am surprised there is not already a list for this somewhere. On Fri, 26 Oct 2012 23:50:04 -0400, Michael Dunn <md@...> wrote: Thanks for all the info. I have a couple of 7844s in need of
repair, so may end up with one working unit, and a display board
donor...?
Michael
|
Re: 7000 series on-screen displays boards
Thanks for all the info. I have a couple of 7844s in need of repair, so may end up with one working unit, and a display board donor...?
Michael
|
The capacitors should be more important than the sense lines. They provide part of each regulator's frequency and phase compensation. I would be suspicious if not hooking up the sense lines has an effect. They are all shunted to the main lines via low value resistors from 47 to 470 ohms. Could one or more of those resistors be partially open? Or maybe the pole-zero compensation in one of the regulators (resistor and capacitor in series like R3278/C3278 and R3289/C3289 in the -15 volt regulator) is bad. The -15 and -50 volt regulators are more liable to oscillate because their NPN output power stages have gain. They have extra frequency compensation of their output stages to help control that. On Fri, 26 Oct 2012 20:48:35 -0000, "Albert" <aodiversen@...> wrote: Hi Jerry,
Nothing helped to get rid of the oscillations when using my testload. True oscillation, about 12 MHz. So as a final attempt I also made sense lines connections, something I never did before. Against my expectation this cured the problem! There still is some switching noise in the rhythm of the inverter, but the DC voltages are fine now.
This is the final configuration (|| means in parallel):
+/-50V both 470R || 1k5, both 10uF to GND
+/-15V both 22R || 22R, both 100uF to GND
+5V 6R8 || 6R8, 100uF to GND
+5VL 5R6 (to GND Lights, I did not connect pin 3 and pin 7).
No other ground wires, except earth from chassis PS to chassis main frame to be on the safe side. All loads via the 10-pin LV connector and the 6-pin Sense connector. So nothing at the 54V lines for the HV supply.
I didn't try it yet with less load, and I added the caps (values taken from the Main Interface Board) before I added the sense lines. So maybe these are not (all) needed. Anyway the result could be used as a guide I think. I used forced cooling; some resistors had to dissipate a little more power more than rated for.
Albert
---
I would expect the sense lines to be needed? They are directly connected on the interface.
Jerry Massengale
|
Re: Estate sale scopes...
I figured it was Chinese USB scopes in the other place ?
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From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Jim
Sent: Friday, October 26, 2012 8:33 PM
To: TekScopes@...
Subject: Re: [TekScopes] Re: Estate sale scopes...?
Well, the other place has Jetronic 545s .... ?
From: jtjewell83 <jtjewell83@...>
To: TekScopes@...
Sent: Friday, October 26, 2012 8:26 PM
Subject: [TekScopes] Re: Estate sale scopes...
If Heaven don't have Tek scopes, I don't wanna gooooo!!!?
|
Re: Estate sale scopes...
Well, the other place has Jetronic 545s ....
Jim N6OTQ
From: jtjewell83
To: TekScopes@...
Sent: Friday, October 26, 2012 8:26 PM
Subject: [TekScopes] Re: Estate sale scopes...
If Heaven don't have Tek scopes, I don't wanna gooooo!!!?
|
Re: Estate sale scopes...
If Heaven don't have Tek scopes, I don't wanna gooooo!!!
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--- In TekScopes@..., Ron York <freelunch@...> wrote:
You can't take it with you, so we ought to enjoy those things that
give us pleasure while we are able to.
Ron
On 10/25/12, Miroslav Pokorni <mpokorni@...> wrote:
Well put Laura,
But most us do not heed the warning.
Miroslav Pokorni
On 10/24/2012 9:20 PM, Laura Tighe wrote:
This should be a lesson. You can't take it with you.
Laura
two bids already ( although could be a tube scrounger at that price)
Dave
On 10/24/2012 8:59 AM, Craig Sawyers wrote:
Not my auction:
. com/itm/19074405 4939
<>
SWMBO would kill be if I even bid, let alone won it ...
Yeah - me too. I'm under increasing pressure to downsize, let alone buy
that lot.
Please someone do - I'd hate them to go into recycling.
Craig
|
David Hess
Michael Dunn