Date   
Re: Tek 2753P Manuals

george edmonds
 

I have repaired many thousands of SMPSU.s, using a variac is not necessary, but, an in series incandescent light bulb is absolutely vital if you wish to avoid a total self destruction at times. It is easier to be safe than sorry.

73 George G6HIG

Re: Deane Kidd and the Metric System

EricJ
 

That makes more sense. For myself, I can convert back and forth pretty easily most of the time in my head already after 20+ years of doing it daily. It's pretty easy for me to think in both measurement systems these days.

--Eric
Sent from my Samsung Galaxy S8.

-------- Original message --------From: "Fabio Trevisan fabio.tr3visan@... [TekScopes]" <TekScopes@...> Date: 12/15/17 8:39 AM (GMT-06:00) To: TekScopes@... Subject: Re: [TekScopes] Deane Kidd and the Metric System

 









Guys,



I think what Ian Newman meant is that you can easily do that conversion by

heart, without resorting to a calculator or a piece of paper to make the

full division or multiplication operation.

It's a no-brainer to repeatedly double the quotient and the divisor until

the divisor reaches 256, and just take note of what the quotient became to

get the result directly in 10ths of mm. With an error of just 0.78%!



I think it goes particularly intuitive to the ones of us who dealt more

with binary logic who can tell by heart most of the smaller powers of 2 and

the relation between all of them.



Rgrds from Brazil,



Fabio



2017-12-15 11:28 GMT-02:00 Eric J wyzkydd2358@... [TekScopes] <

TekScopes@...>:



Same. I was a machinist, toolmaker and welder for 20 years until I injured
my back. We always used 25.4 for conversion from inch to metric and vice
versa, it is correct and gives the exact conversion.
--Eric
Sent from my Samsung Galaxy S8.
-------- Original message --------From: "Barry n4buq@...
[TekScopes]" <TekScopes@...> Date: 12/14/17 7:48 PM
(GMT-06:00) To: TekScopes@... Subject: Re: [TekScopes] Deane
Kidd and the Metric System
I worked in a metric shop for 10 years. I pretty much always used 25.4 as
the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is
technically the correct conversion factor between inches and millimeters
(and easier for me to remember).
Thanks,
Barry - N4BUQ
----- Original Message -----
From: "Tom Jobe tomjobe@... [TekScopes]" <
TekScopes@...>
To: TekScopes@...
Sent: Thursday, December 14, 2017 6:36:53 PM
Subject: Re: [TekScopes] Deane Kidd and the Metric System
That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...

Re: Deane Kidd and the Metric System

Fabio Trevisan
 

Guys,

I think what Ian Newman meant is that you can easily do that conversion by
heart, without resorting to a calculator or a piece of paper to make the
full division or multiplication operation.
It's a no-brainer to repeatedly double the quotient and the divisor until
the divisor reaches 256, and just take note of what the quotient became to
get the result directly in 10ths of mm. With an error of just 0.78%!

I think it goes particularly intuitive to the ones of us who dealt more
with binary logic who can tell by heart most of the smaller powers of 2 and
the relation between all of them.

Rgrds from Brazil,

Fabio



2017-12-15 11:28 GMT-02:00 Eric J wyzkydd2358@... [TekScopes] <
TekScopes@...>:



Same. I was a machinist, toolmaker and welder for 20 years until I injured
my back. We always used 25.4 for conversion from inch to metric and vice
versa, it is correct and gives the exact conversion.
--Eric
Sent from my Samsung Galaxy S8.
-------- Original message --------From: "Barry n4buq@...
[TekScopes]" <TekScopes@...> Date: 12/14/17 7:48 PM
(GMT-06:00) To: TekScopes@... Subject: Re: [TekScopes] Deane
Kidd and the Metric System



I worked in a metric shop for 10 years. I pretty much always used 25.4 as
the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is
technically the correct conversion factor between inches and millimeters
(and easier for me to remember).

Thanks,

Barry - N4BUQ

----- Original Message -----

From: "Tom Jobe tomjobe@... [TekScopes]" <
TekScopes@...>

To: TekScopes@...
Sent: Thursday, December 14, 2017 6:36:53 PM
Subject: Re: [TekScopes] Deane Kidd and the Metric System
That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...
[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]

Re: 7904A readout bounce

Roger Evans
 

I have just had a look to see what my 7934 (same Y amplifier and channel switch) does at slow sweep speeds. If I put one of the Y traces near the top of the screen and one at the bottom and set the sweep speed to 100msec/div then I see a small shift of the top and bottom readout positions as the beam alternates between the two traces. The movement is at most 0.05 of a major division, quarter of a minor division When the upper beam is displayed both readouts move slightly downwards, when the lower beam is displayed the readouts move up slightly. If I put the two traces near each other, anywhere on the screen, the readout does not move. At 10msec/div the movement is about the same but more objectionable, at anything faster than 1msec/div the readouts are steady. This seems consistent with thermal effects and David explained it very clearly.

IWhat sweep speeds are you using and how much movement of the readout do you see?

Roger

Re: Deane Kidd and the Metric System

EricJ
 

Same. I was a machinist, toolmaker and welder for 20 years until I injured my back. We always used 25.4 for conversion from inch to metric and vice versa, it is correct and gives the exact conversion.
--Eric
Sent from my Samsung Galaxy S8.

-------- Original message --------From: "Barry n4buq@... [TekScopes]" <TekScopes@...> Date: 12/14/17 7:48 PM (GMT-06:00) To: TekScopes@... Subject: Re: [TekScopes] Deane Kidd and the Metric System

 









I worked in a metric shop for 10 years. I pretty much always used 25.4 as the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is technically the correct conversion factor between inches and millimeters (and easier for me to remember).



Thanks,

Barry - N4BUQ



----- Original Message -----

From: "Tom Jobe tomjobe@... [TekScopes]" <TekScopes@...>
To: TekScopes@...
Sent: Thursday, December 14, 2017 6:36:53 PM
Subject: Re: [TekScopes] Deane Kidd and the Metric System
That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example   (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...

Re: Deane Kidd and the Metric System

Vince Vielhaber
 

You guys are all doing it the hard way. When I need to do a conversion I
just ask the Google Home I keep in the shop: Hey Google, what's 283.4mm
in inches? And she tells me.

Vince.

I worked in a metric shop for 10 years. I pretty much always used 25.4 as
the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is
technically the correct conversion factor between inches and millimeters
(and easier for me to remember).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Jobe tomjobe@... [TekScopes]"
<TekScopes@...>
To: TekScopes@...
Sent: Thursday, December 14, 2017 6:36:53 PM
Subject: Re: [TekScopes] Deane Kidd and the Metric System

That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example   (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...


On 12/14/2017 4:02 PM, 'Craig Sawyers' c.sawyers@...
[TekScopes] wrote:

On the topic of conversion between Imperial and SI units of length
there is a well known method of
quickly converting aliquot parts of an inch to millimetres using the
approximation 254 = 256

If you have a fractional inch dimension, multiply top and bottom of
the fraction by two repeatedly
until
the denominator equals 256.? Shift the decimal point of top and
bottom one place to the left.? The
numerator now equals the inch dimension times 25.6, which is the
equivalent number of millimetres
(to less than 1% error)
Ian
Darn, that is a neat trick. I really like simple numerical methods
like that.

Craig







------------------------------------

------------------------------------


------------------------------------

Yahoo Groups Links



Re: Deane Kidd and the Metric System

stefan_trethan
 

Come on guys, surely it was a joke!
It's like saying to get from feet to inches divide by 0.08333333.

ST

On Fri, Dec 15, 2017 at 2:48 AM, Barry n4buq@... [TekScopes]
<TekScopes@...> wrote:
I worked in a metric shop for 10 years. I pretty much always used 25.4 as the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is technically the correct conversion factor between inches and millimeters (and easier for me to remember).

Thanks,
Barry - N4BUQ

Re: 7904A readout bounce

NigelP
 

Seems odd, but let's be quite specific about what I see; the readout jumps up and then down exactly at the start of each alternate sweep; difficult to imagine that this is a thermal problem... it's almost as if a switch is being thrown one way and the other at the start of each sweep (and indeed somewhere in the sweep circuitry that is probably exactly what is happening.... by design)? Also, the effect is quite flip-flop, so not increasing with sweep position but actually at the start of each sweep; one might argue that it's coincident with each sweep gate.

What I have not yet checked is whether fully overlaying two or four alternate traces on the screen minimises the effect; in other words whether it is the shift in vertical displacement of the normal two or four scan lines that is attributing to the readout display shift.

Anyway the bottom line is that the thermal compensation adjustment process is not actually solving the issue. I can see that if I adjust (eg R131 @ 50mS sweep) to one extreme or the other I can observe readout jitter going in or out but it doesn't seem to minimise the bounce.

Nigel

Re: Tek 2753P Manuals

John Miles
 

There's not much upside in using the old Variac and/or light-bulb trick to
bring up a switching power supply. The switcher won't generally fail in a
way that draws excess AC line current. If a secondary rail is shorted, it
will simply refuse to start. Meanwhile, the combination of a shorted
secondary rail and an unusual high-impedance or low-voltage AC power
connection may not have been well-characterized by the original designer.
The best strategy is to just plug it in and hit the power switch.



-- john, KE5FX

Author/maintainer of the 49x service document, FWIW :)



From: TekScopes@... [mailto:TekScopes@...]
Sent: Thursday, December 14, 2017 5:35 PM
To: TekScopes@...
Subject: [TekScopes] Re: Tek 2753P Manuals





So, I found some manuals for a 494AP which is similar to mine. Also found
some 494 repair notes which looks to be a good find. Anyway, I finally got
around to powering it up with a dim bulb circuit and a 200W bulb. A couple
LEDS on the front came on and the scope backlights but that is it. The bulb
in the test circuit also lit to about half brightness I would guess, not
sure if it's safe to hook up to the variac and get some power board
voltages??? Got the case off, very nice and clean inside, good sign. One of
the main filter caps has the plastic a little ruffled on top so maybe that
got a little hot at some point. Having a little difficulty getting to the
power board, not sure if the go by from the 494 is the same so I am kinda
hesitant to go any further trying to disassemble it. Hoping it's just a few
electrolytics to replace get her up and going. The downside to this unit is
that it is a huge beast of a machine. Have no clue where I will set this up
if I ever get it going.

http://www.antiqueradios.com/forums/download/file.php?id=198994

Re: Deane Kidd and the Metric System

Tom Gardner
 

On 14/12/17 22:57, Ian Newman ian_new@... [TekScopes] wrote:

Hi,
On the topic of conversion between Imperial and SI units of length there is a well known method of quickly converting aliquot parts of an inch to millimetres using the approximation 254 = 256
How very annoyingly neat and simple. Annoying because I didn't think of it myself.

It makes pi*pi == g == 10 look boring.

Anyway, thanks; email saved!

Re: My tek 2465 smokes

Tom Gardner
 

On 15/12/17 06:51, 'hardy hansen' hardyhansen@... [TekScopes] wrote:

After not having used my tek 2465 for a while-now it really smokes-do vagely recall it have been seen before??

Any advise welcome as i am not in a position right now to dig very deep because of health issues.
A good starting point would be
http://www.condoraudio.com/wp-content/uploads/Projects/Tektronix-2465B-Oscilloscope-Restoration-Repair.pdf

Re: Deane Kidd and the Metric System

Craig Sawyers <c.sawyers@...>
 

Damn. *Were* you pulling our leg Tom? If so you suckered me into getting on my theory high horse!

Craig

Memorizing the number .03937 solves the whole problem going either
way, to or from inches and millimeters.
That is a more difficult and much more imprecise number to remember than 25.4. That is by
definition
the precise conversion. Whereas 1/25.4 ~ 0.03937 are the first digits of a repeating decimal
(since it can
be expressed as 10/254, and a fraction of two integers always returns a repeating decimal, as a
simple
example 1/9 = 0.11111...). It turns out that the repeat length of 1/254 (and hence of
10/254 = 1/25.4)) is 42 digits long!

Craig

Re: Deane Kidd and the Metric System

Craig Sawyers <c.sawyers@...>
 

Memorizing the number .03937 solves the whole problem going either way, to or from inches and
millimeters.
That is a more difficult and much more imprecise number to remember than 25.4. That is by definition
the precise conversion. Whereas 1/25.4 ~ 0.03937 are the first digits of a repeating decimal (since
it can be expressed as 10/254, and a fraction of two integers always returns a repeating decimal, as
a simple example 1/9 = 0.11111...). It turns out that the repeat length of 1/254 (and hence of
10/254 = 1/25.4)) is 42 digits long!

Craig

Re: My tek 2465 smokes

cmjones01
 

On 15 Dec 2017 7:52 a.m., "'hardy hansen' hardyhansen@...
[TekScopes]" <TekScopes@...> wrote

After not having used my tek 2465 for a while-now it really smokes-do
vagely recall it have been seen before??

The smoke is probably from the mains input filter capacitors which, after a
few decades, crack and admit moisture, then fail with a cloud of smoke. The
proper fix is to replace the capacitors. The fix I use is just to wait for
the smoke to stop (it does, eventually) and carry on using the scope.

The operation of the instrument is not affected by these capacitors, but
there's a chance it won't meet its conducted radio interference spec if
they've failed. You are free to decide whether this is something you care
about.

Chris

Re: My tek 2465 smokes

Ed Breya
 

You said it smokes, but does it run? Open it up and look for the source. Could be one of the infamous bad X-caps, or something else burning up and ready to crap out entirely. It's best to look while there's still some smoke left.

Ed

My tek 2465 smokes

hardyhansendk
 

Hello

After not having used my tek 2465 for a while-now it really smokes-do vagely recall it have been seen before??

Any advise welcome as i am not in a position right now to dig very deep because of health issues.

Thanks

Hardy.





Fra: TekScopes@... [mailto:TekScopes@...]
Sendt: 14. december 2017 17:58
Til: TekScopes@...
Emne: Re: [TekScopes] My 2462A died suddenly





El 14/12/2017 a las 10:47 a.m., machine guy @Mac
[TekScopes] escribió:

Sorry, my reply will be slow and limited while on holiday. Your
symptoms seem like a bad capacitor. There is a fault in the service
manual that interchanges C1115 and C1132. This causes you to fit a 35
volt capacitor (c115) in a 87 volt circuit (where C1132 should be).
So trust the schematic and your ohm meter, buzz out the circuit and
make certain that your caps are fitted to the schematic. Ignore the
board outline drawings.

Sent from Yahoo Mail for iPhone

On Tuesday, December 12, 2017, 4:35 AM, Joachim Lange ti8jlh@...
[TekScopes] <TekScopes@...> wrote:


El 10/12/2017 a las 11:54 p.m., machine guy @Mac
[TekScopes] escribió:

Glad to hear it is fixed. Thanks for reporting back. I was worried
because I am leaving for a winter holiday and was not going to be much
help until 2018. Best wishes for the Holidays.
Mac

On ‎Saturday‎, ‎December‎ ‎9‎, ‎2017‎ ‎09‎:‎09‎:‎38‎ ‎PM‎ ‎CST,
Joachim Lange ti8jlh@... [TekScopes] <TekScopes@...>
wrote:


El 08/12/2017 a las 01:30 a.m., machine guy @Mac
[TekScopes] escribió:

Change C1066. Then verify that you have the dummy load connected
properly and check the voltage on the collector of Q1062. If the
voltage on the collector of Q1062 is wrong after that, double check
the voltages on Q1050. Here is how everything is supposed to work:
Q1050 creates pulses that energize T1050. One of the windings of
T1050 drive a full wave rectifier CR1062 through CR1065. The
rectified pulses are filtered by C1066 to provide the 12.5 volts on
the collector of Q1062. Its pretty hard for other parts, like Q1066,
to drag down that voltage. I think Q1062 would get really hot if that
were happening. My opinion, is that either T1050 is not being properly
energized or there is a fault in the rectifiers CR1062 through CR1065,
or the filter capacitor C1066 is not storing enough energy. C1066 is
the most likely fault and its easy to change.

On ‎Thursday‎, ‎December‎ ‎7‎, ‎2017‎ ‎08‎:‎49‎:‎57‎ ‎PM‎ ‎CST,
Joachim Lange ti8jlh@... [TekScopes] <TekScopes@...>
wrote:


El 04/12/2017 a las 12:18 a.m., machine guy @Mac
[TekScopes] escribió:

Its a problem that the voltage on the emitter of Q1062 is less
than 11
Volts. Check the voltage on the collector of Q1062, it should be at
least 12.5 Volts. If it is not, check C1066 (or replace it). Until
you get the voltage at the collector of Q1062 and emitter of Q1062
right the gate drives of Q1060 and Q1070 will have errors that can
keep the rest from working.

On ‎Sunday‎, ‎December‎ ‎3‎, ‎2017‎ ‎08‎:‎30‎:‎33‎ ‎PM‎ ‎CST,
Joachim
Lange ti8jlh@... [TekScopes] <TekScopes@yahoogroups..com>
wrote:


El 17/11/2017 a las 01:18 a.m., machine guy @Mac
[TekScopes] escribió:

Much of the 2465B is the same as the 2465A. The power supplies are
identical. But a service manual for the 2565A will eventually be
necessary (calibration, etc.). I got the manual for my 2465A from
Artek manuals. They are excellent scans of original manuals. The
owner is a member of this group.
On Thursday, November 16, 2017, 8:27:10 PM CST, Joachim Lange
ti8jlh@... [TekScopes] <TekScopes@...> wrote:


El 16/11/2017 a las 06:28 p.m., machine guy @Mac
[TekScopes] escribió:

First, I assume you are aware that the power supply will not
operate
properly without a load and may in fact be damaged if operated
without
a load. After that, I am very doubtful that the problem is
caused by
U1030 (a TL494). The operation of U1030 depends on voltage
from the
collector of Q1021 and you measured that to be zero. I am not
concerned that you have a TL594 instead of a TL494, I think
TL594 is a
suitable substitute for a TL494. So I suggest you not change
TL494
without more information.
Second, I assume you are aware that measurements in this
area are
directly connected to mains power and can be dangerous. It is
advisable that you use an isolation transformer to remove the
scope
from direct mains connections when working in this area. After
that,
the zero voltage on Q1021 collector is a key indicator that the
PSU is
not starting at all. You may want to refer to the service manual
theory of operation for the PSU and the key role that Q1021
plays in
start up and static operation. Specifically, the conduction of
Q1021
depends on base current drive from Q1022 and Q1022 can be shut
down by
over-current sensed by Q1040. More measurement in this area
may give
a clue to why there is no voltage on the collector of Q1021. I
suspect the collector voltage on Q1040 will be low (say less
than 6
volts).
Did you check the resistance of R1020 and the leakage of C1025?

On Thursday, November 16, 2017, 4:58:03 PM CST, Joachim Lange
ti8jlh@... [TekScopes] <TekScopes@...> wrote:


Hello everybody,
I hope you can help me repairing the PSU of my 2465A.
I took out the power supply and connected it to power. The fuses
all are
ok. I coud see that there is a voltage at the emitter of
Q1021. Not
exactly 13.2V but one more Volt. At the colector of the same
Q1021
there
is 0V.
I revised all the resistors and also Q1021, Q1022, Q1030,
Q1040 and
Q1050. Also all the CR's (diodes).All these components are good.
I did not pull out U1030 because I am a little unsecure
doing that
and I
don't have a TL494. The scope has a TL594 instead. Are they the
same?
I will look at the computer PS I have laying around because I
think
these ICs are installed in some of those.
But please could anybody tell me if this could be the failure?
I have some other questions about the caps in this PSU but I
will make
them later.
Thank you very much for your advises.

Joachim TI8JLH

[Non-text portions of this message have been removed]

Thank you for your fast answer.
Yes the resistance R1020 is ok and C1025 looks healty.
Tomorrow I will assemble the two parts and look for the voltage
on the
collector of Q1021.
I was searching for the theory of operation on the web because my
manual
don¨t have it. I found one for 2465B.
The low power supplies are the same for both models.
I will write tomorrow with more.
Thank you

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hello,
Thank you for your help.
I am still trying to repair the PSU.
I replaced 11 resistors. Most of them were open and the others
doubled
their value. Also three caps looked as they were leaking. I replaced
them too. (the ESR was ok)
I reasembled the PSU and at first I was very happy, but after one
minute
the screen began to flicker and than it turned off.
I took it off again and build the Primary Test Load and also I
used my
power supply. Not together.
With the Test Load connected there is 120V across load but the gate
drives of Q1060 and Q1070 is only 4.6V instead of 11V.
The volts supplied from emitter of Q1062 is about 9V.
The U1030 is working. The gate drive of Q1050 is ok.
Do you think that the regulator board is the problem or could it be
U1066?
Thank's
Joachim





Hello
Now I got again 120V at the test load. I removed U1066 and used a
socket
to install it.
With the U1066 in place I have the same voltages as before.
With the removed U1066 there as about 10V at the gates and 10V on the
emitter of Q1062.
I wanted to know what is bringing down the voltages on the emitter and
collector of Q1062.
Without U1066 the voltages still dont match.
May be it is the Q1062.
Do you have an idea how to check for the missig voltages?
Thank you.

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hello ,
I am very sorry to tell you about the mistake I made and that made me
waste my time and a lot of energy.
I forgot to bridge J207 and J206.
After I did that, voltages are ok now.
Thanks for your time and for your explanation of the circuit.
I'm very sorry for wasting your time and of the others who helped.
Regards
Joachim

[Non-text portions of this message have been removed]



Hello Mac,
When I turned the scope on it worked for half hour and than it started
blinking. All leds where blinking and on the screen there was a big dot
tha disappeared and came back and so on.
I took the PSU apart again and connected the load I built.
The voltages on emitter of Q1062 is over 11V and the collector has about
19V.
BUT the gate drives of Q1060 and Q1070 are only 5.6V and not 11V.
Must I replace U1062, U1064 and U1066?
What do you think?
Sorry for bother you again on your holydays.
Joachim



#yiv5774964079 #yiv5774964079 -- #yiv5774964079ygrp-mkp {border:1px
solid #d8d8d8;font-family:Arial;margin:10px 0;padding:0
10px;}#yiv5774964079 #yiv5774964079ygrp-mkp hr {border:1px solid
#d8d8d8;}#yiv5774964079 #yiv5774964079ygrp-mkp #yiv5774964079hd
{color:#628c2a;font-size:85%;font-weight:700;line-height:122%;margin:10px
0;}#yiv5774964079 #yiv5774964079ygrp-mkp #yiv5774964079ads
{margin-bottom:10px;}#yiv5774964079 #yiv5774964079ygrp-mkp
.yiv5774964079ad {padding:0 0;}#yiv5774964079 #yiv5774964079ygrp-mkp
.yiv5774964079ad p {margin:0;}#yiv5774964079 #yiv5774964079ygrp-mkp
.yiv5774964079ad a {color:#0000ff;text-decoration:none;}#yiv5774964079
#yiv5774964079ygrp-sponsor #yiv5774964079ygrp-lc
{font-family:Arial;}#yiv5774964079 #yiv5774964079ygrp-sponsor
#yiv5774964079ygrp-lc #yiv5774964079hd {margin:10px
0px;font-weight:700;font-size:78%;line-height:122%;}#yiv5774964079
#yiv5774964079ygrp-sponsor #yiv5774964079ygrp-lc .yiv5774964079ad
{margin-bottom:10px;padding:0 0;}#yiv5774964079 #yiv5774964079actions
{font-family:Verdana;font-size:11px;padding:10px 0;}#yiv5774964079
#yiv5774964079activity
{background-color:#e0ecee;float:left;font-family:Verdana;font-size:10px;padding:10px;}#yiv5774964079
#yiv5774964079activity span {font-weight:700;}#yiv5774964079
#yiv5774964079activity span:first-child
{text-transform:uppercase;}#yiv5774964079 #yiv5774964079activity span
a {color:#5085b6;text-decoration:none;}#yiv5774964079
#yiv5774964079activity span span {color:#ff7900;}#yiv5774964079
#yiv5774964079activity span .yiv5774964079underline
{text-decoration:underline;}#yiv5774964079 .yiv5774964079attach
{clear:both;display:table;font-family:Arial;font-size:12px;padding:10px 0;width:400px;}#yiv5774964079
.yiv5774964079attach div a {text-decoration:none;}#yiv5774964079
.yiv5774964079attach img
{border:none;padding-right:5px;}#yiv5774964079 .yiv5774964079attach
label {display:block;margin-bottom:5px;}#yiv5774964079
.yiv5774964079attach label a {text-decoration:none;}#yiv5774964079
blockquote {margin:0 0 0 4px;}#yiv5774964079 .yiv5774964079bold
{font-family:Arial;font-size:13px;font-weight:700;}#yiv5774964079
.yiv5774964079bold a {text-decoration:none;}#yiv5774964079
dd.yiv5774964079last p a
{font-family:Verdana;font-weight:700;}#yiv5774964079
dd.yiv5774964079last p span
{margin-right:10px;font-family:Verdana;font-weight:700;}#yiv5774964079
dd.yiv5774964079last p span.yiv5774964079yshortcuts
{margin-right:0;}#yiv5774964079 div.yiv5774964079attach-table div div
a {text-decoration:none;}#yiv5774964079 div.yiv5774964079attach-table
{width:400px;}#yiv5774964079 div.yiv5774964079file-title a,
#yiv5774964079 div.yiv5774964079file-title a:active, #yiv5774964079
div.yiv5774964079file-title a:hover, #yiv5774964079
div.yiv5774964079file-title a:visited
{text-decoration:none;}#yiv5774964079 div.yiv5774964079photo-title a,
#yiv5774964079 div.yiv5774964079photo-title a:active, #yiv5774964079
div.yiv5774964079photo-title a:hover, #yiv5774964079
div.yiv5774964079photo-title a:visited
{text-decoration:none;}#yiv5774964079 div#yiv5774964079ygrp-mlmsg
#yiv5774964079ygrp-msg p a span.yiv5774964079yshortcuts
{font-family:Verdana;font-size:10px;font-weight:normal;}#yiv5774964079
.yiv5774964079green {color:#628c2a;}#yiv5774964079
.yiv5774964079MsoNormal {margin:0 0 0 0;}#yiv5774964079 o
{font-size:0;}#yiv5774964079 #yiv5774964079photos div
{float:left;width:72px;}#yiv5774964079 #yiv5774964079photos div div
{border:1px solid
#666666;min-height:62px;overflow:hidden;width:62px;}#yiv5774964079
#yiv5774964079photos div label
{color:#666666;font-size:10px;overflow:hidden;text-align:center;white-space:nowrap;width:64px;}#yiv5774964079
#yiv5774964079reco-category {font-size:77%;}#yiv5774964079
#yiv5774964079reco-desc {font-size:77%;}#yiv5774964079
.yiv5774964079replbq {margin:4px;}#yiv5774964079
#yiv5774964079ygrp-actbar div a:first-child
{margin-right:2px;padding-right:5px;}#yiv5774964079
#yiv5774964079ygrp-mlmsg {font-size:13px;font-family:Arial, helvetica,
clean, sans-serif;}#yiv5774964079 #yiv5774964079ygrp-mlmsg table
{font-size:inherit;font:100%;}#yiv5774964079 #yiv5774964079ygrp-mlmsg
select, #yiv5774964079 input, #yiv5774964079 textarea {font:99% Arial,
Helvetica, clean, sans-serif;}#yiv5774964079 #yiv5774964079ygrp-mlmsg
pre, #yiv5774964079 code {font:115% monospace;}#yiv5774964079
#yiv5774964079ygrp-mlmsg * {line-height:1.22em;}#yiv5774964079
#yiv5774964079ygrp-mlmsg #yiv5774964079logo
{padding-bottom:10px;}#yiv5774964079 #yiv5774964079ygrp-msg p a
{font-family:Verdana;}#yiv5774964079 #yiv5774964079ygrp-msg
p#yiv5774964079attach-count span
{color:#1E66AE;font-weight:700;}#yiv5774964079 #yiv5774964079ygrp-reco
#yiv5774964079reco-head {color:#ff7900;font-weight:700;}#yiv5774964079
#yiv5774964079ygrp-reco
{margin-bottom:20px;padding:0px;}#yiv5774964079
#yiv5774964079ygrp-sponsor #yiv5774964079ov li a
{font-size:130%;text-decoration:none;}#yiv5774964079
#yiv5774964079ygrp-sponsor #yiv5774964079ov li
{font-size:77%;list-style-type:square;padding:6px 0;}#yiv5774964079
#yiv5774964079ygrp-sponsor #yiv5774964079ov ul {margin:0;padding:0 0 0
8px;}#yiv5774964079 #yiv5774964079ygrp-text
{font-family:Georgia;}#yiv5774964079 #yiv5774964079ygrp-text p
{margin:0 0 1em 0;}#yiv5774964079 #yiv5774964079ygrp-text tt
{font-size:120%;}#yiv5774964079 #yiv5774964079ygrp-vital ul
li:last-child {border-right:none !important;}#yiv5774964079



Hi,
I replaced U1062 and U1064 because there were laying around. but I don't
have U1066.
Now what I can see is that there is 11V on one gate of the Q1060 or
Q1070 and on the other there are only 5V.
Looks that U1066 is bad?
Capacitors are ok.
Thank you for responding on your holydays.
Joachim








<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient>

Virusfri. <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient> www.avg.com





[Non-text portions of this message have been removed]

Re: Deane Kidd and the Metric System

stefan_trethan
 

Thanks, Ian, for that neat trick with the 256 method. I'll use it for sure.

And thank you Tom, for pulling our leg. ;-)

ST

On Fri, Dec 15, 2017 at 1:36 AM, Tom Jobe tomjobe@...
[TekScopes] <TekScopes@...> wrote:
That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...

Re: c-12 camera

Glydeck
 

I love this!

Sent from my iPad

On Dec 14, 2017, at 8:04 AM, 'Craig Sawyers' c.sawyers@... [TekScopes] <TekScopes@...> wrote:

That is really neat!

Craig

See my flower pot adapter for a 7623A:

https://eb4apl.ure.es/camerascope/camscope_en.htm

Regards,

Ignacio, EB4APL

[Non-text portions of this message have been removed]

Replacement caps for 465B

n4buq
 

Anyone have a good list / supplier for the electrolytic caps in the LVPS of a 465B? I had some of the adapter discs made (the kind that take a snap-in cap) so looking for that form factor.

Here's the specs from the manual:

C4419 5000uF 25V +100% / -0%
C4429 1200uF 100V +75% / -10%
C4439 550uF 100V +75% / -10%
C4521 5500uF 30V +100% / -10%
C4531 5000uF 25V +100% / -10%

Was considering the same 6800uF, 35V, 20% cap (Mouser P/N 647-LGU1V682MELZ) for C4419, C4521, and C4531. Given they're originally +100% caps, I presume that'd be okay? Anyone have better choices?

Thanks,
Barry - N4BUQ

Re: Deane Kidd and the Metric System

n4buq
 

I worked in a metric shop for 10 years. I pretty much always used 25.4 as the conversion factor. 0.03937 is a rounded recriprocal of 25.4 which is technically the correct conversion factor between inches and millimeters (and easier for me to remember).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Jobe tomjobe@... [TekScopes]" <TekScopes@...>
To: TekScopes@...
Sent: Thursday, December 14, 2017 6:36:53 PM
Subject: Re: [TekScopes] Deane Kidd and the Metric System

That is a very neat trick... but consider this simple plan:
For the fractional part of the dimension, divide the bottom number into
the top number to get its decimal equivalent.
Example   (7/16" = 7 divided by 16 gives you 0.4375 inches)
If there are whole inches involved in the measurement then it becomes
1.4375, 2.4375 etc.
Divide the decimal inch number by .03937 and you have your millimeter
equivalent.
Example ( our 7/16" is 0.4375 decimal inches, we divide it by .03937 and
we have our answer of 11.11125 mm.
Memorizing the number .03937 solves the whole problem going either way,
to or from inches and millimeters.
Let's have an example of going from millimeters to inches:
If you multiply 100mm by .03937 you will get it's equivalent in inches,
100 x .03937 = 3.937 inches.
The number .03937 is simply how many inches are in one millimeter.
This .03937 method was the common way that millimeters and inches were
dealt with in shops I worked at in the US.
tom jobe...


On 12/14/2017 4:02 PM, 'Craig Sawyers' c.sawyers@...
[TekScopes] wrote:

On the topic of conversion between Imperial and SI units of length
there is a well known method of
quickly converting aliquot parts of an inch to millimetres using the
approximation 254 = 256

If you have a fractional inch dimension, multiply top and bottom of
the fraction by two repeatedly
until
the denominator equals 256.? Shift the decimal point of top and
bottom one place to the left.? The
numerator now equals the inch dimension times 25.6, which is the
equivalent number of millimetres
(to less than 1% error)
Ian
Darn, that is a neat trick. I really like simple numerical methods
like that.

Craig



[Non-text portions of this message have been removed]



------------------------------------

------------------------------------


------------------------------------

Yahoo Groups Links