Date   

Re: Another 7D20 attenuator question

Dallas Smith
 

Another thought, I'm thinking about cutting little squares from the dual fingers from a donor time base switch and solder them to the pads for a gold contact surface.


Re: Tek 465 Turns on, No Dot, No Trace

Stephen
 

In the process of replacing those 2 caps.
They are not easy to take out.
Replacing the 3000uF 35v with a modern 3300uF 63V, and the 5000uF 25V with a modern 4700uF 63V (or maybe a 6800uF 63V), whichever fits better...


Re: New member with a currently-dead 2465

Vincent Mallet
 

Thanks Siggi. The scope is a 2465 300Mhz, S/N B027189. I don't see any smd
components on the A5 board. I don't think the scope has any options but I'm
not too sure how to tell yet.

I looked at the joints of the oscillating circuit components under a
microscope and they looked fine (to my untrained eyes); I tested
conductivity between leads around this area and it matched expectations. I
wiggled things a bit and flexed the board very gently and powered things
back on, still a flat line there.

Thanks,

Vince.

On Fri, Jul 10, 2020 at 8:01 AM Siggi <siggi@...> wrote:

Hey Vincent,

congrats on your 2465, I'm sure you'll get'er going again in no time.
Just to make sure though, is this a 2465 or a 2465A/B? There are important
differences between the three - notably the A5 board in the 2465B suffers
from surface mount capacitor leakage.

Inline.

Siggi

On Thu, Jul 9, 2020 at 9:05 PM Vincent Mallet <vmallet@...> wrote:

Question: how likely is it that the oscillator circuit has failed?

It happens.


Or could
there be an external factor preventing it from oscillating that I don't
see?
This can probably happen also :).
You may want to try and gently flex the board and maybe wiggle the
components involved. IIRC the crystal stands fairly proud, and so may
suffer vibration or shock damage. Best case you have a poor solder joint
somewhere.



My next step would be to pull the few components from the oscillating
circuit out so I can test them but I figured maybe I'd ask around if this
rang a bell first.
I don't remember oscillator death being a common issue.




Re: Cleaning TM500 module pushbutton switches

Ray
 

It might be close to what is called white gas or camping gas, used to fuel portable camping stoves.Colman is one of the brands.It is essential gasoline without any aditives.73Sent from my T-Mobile 4G LTE device------ Original message------From: Nenad FilipovicDate: Fri, Jul 10, 2020 11:04To: TekScopes@groups.io;Cc: Subject:Re: [TekScopes] Cleaning TM500 module pushbutton switchesOn Fri, Jul 10, 2020 at 4:53 PM Colin Herbert via groups.io wrote:

Nenad,
You mention something you call "petroleum benzine". Though I am a retired
research chemist living in Britain, I have no idea of what this is and
others may not also. It _could_ be "petroleum ether", which I am familiar
with, but that comes in various boiling-point ranges and you wouldn't want
to use a high-boiling fraction; 60-40 is the most likely (boiling-range
between 60 and 40 degrees Centigrade/Celsius). Be cautious, this solvent is
very inflammable and not a little smelly. If you are actually thinking of
"benzene" (note the "e", not "i"), then I doubt that anyone in an EU
country would be able to buy that, as it is carcinogenic (causes cancer)
and is therefore controlled. Perhaps you could clarify?
Colin.
Hi Colin,

Yes indeed, I suspected that "petroleum benzine" might cause confusion, and
I'd be glad if we could clear it. The issue is that these damn chemicals
have notorious local names, and something that is quite wide known in one
country can have a completely different name in another, or not be
available at all.

To be honest, I am also not sure about my "petroleum benzine" true content,
but I strongly believe it's just a kind of petroleum ether. It is sold in
pharmacies and has the following uses and properties:
- often called "Benzinum medicinale" and can be looked up by that name in
Europe
- used in medicine as a solvent to clean skin and surfaces off greasy or
similar non-polar contaminants (commonly used to remove traces of adhesive
from skin after patches and bandages are taken off)
- generally used to remove greasy contaminants (as a non-polar solvent),
especially by watchmakers and jewelers
- is "moderately" volatile (e.g. less than acetone)
- is smelly, but certainly not very smelly or outright unpleasant (e.g.
acetone is much more pungent)
- certainly does not smell like benzEne (C6H6), I remember benzene smell
from chemistry classes as much "heavier" and more "oily" than this

These are the only links I found related to its technical properties:
http://www.gram.co.rs/ser/benzin_za_odmascivanje.htm
and
https://www.pharmawiki.ch/wiki/index.php?wiki=Wundbenzin

Due to its pharmaceutical use (application on skin) I was inclined to
believe it is not an aggressive substance. Throughout years of various uses
I can confirm that assumption, I find it mild on rubber and plastic
surfaces. I often use it to clean my photographic lenses, it does an
excellent job on fingerprints and all greasy stuff, evaporates without a
trace, and also no trace/damage on the surrounding plastic parts.

Best regards,
Nenad


Re: Cleaning TM500 module pushbutton switches

Glenn Little
 

Ensure that you remove all traces of the WD40.
WD40 is a water displacer.
It will leave a gummy mess.

Glenn

On 7/10/2020 11:30 AM, Renée wrote:
I have the same issue only with the plastic on plastic ( the actuator for finger poking to the to the outside world) is causing the sticking. they were cleaned with soap and water ( yes disassembled) to remove dirt and then ipa without success. suggestions?
I have used WD40 to soften grease for easier removal. leave it sit for a day or two, sometimes multiple applications...I try not to make it too messy.
thanks for the procedure, some things I had not considered, very helpful!
Renée


On 7/10/20 7:42 AM, Nenad Filipovic wrote:
On Fri, Jul 10, 2020 at 3:05 AM W1PJE <@W1PJE> wrote:
I have multiple TM500 modules that have developed sticky / intermittent
pushbutton switches (the square small ones). Is there a recommended cleaning procedure? I was going to do the standard use of Caig's DeOxit in a sparing manner, but perhaps there is a better way.
In some cases hard patina forms on contact surfaces and DeOxit can be ineffective or just a short term solution. Additionally, DeOxit cannot restore the original grease which is likely fully decomposed and dry due to age. In that case I use the following procedure to restore these without any desoldering: - Gain access, carefully uncouple and remove the pushbutton shaft. - Remove the clamp next to the spring, carefully remove the tiny parts (spring, tiny rocker bolt and its elastic support). - Carefully pull out the switch shaft at the back of the switch body - care must be taken to go slow and grip the two metal contacts (use tweezers) before they fully come out (otherwise they may fly off and get lost). Note (or take photo of) the orientation of contacts with respect to their slot in the shaft (the bend in the middle should be oriented away from the switch body). - If the switch is radio button type it will contain a "clutch" sliding plate that needs to be pushed to one side so the shaft could be released and removed. - Sometimes a PCB component may get in the way of shaft removal, I almost always find it easier to remove the offending component rather than the switch body. - If switch parts are clogged by ancient dried up grease, clean/wash everything (both plastic and metal parts) with a paintbrush in petroleum benzine (pharmaceutical grade, in Europe we get it in regular pharmacies; however most non-polar solvents which are not aggressive to plastic would do). Do not let the plastic parts sit in benzine for too long, all this can and should be done in just a few minutes. Let the clean parts dry. - Using a soft brass brush (I get these at dentist supply shops) gently scrub the patina off the active side of the metal contacts. Soft brass brush should not damage the contact plating that needs to be preserved. - Use cotton ear buds soaked first in petroleum benzine, then IPA to clean the internals of the switch body. I spend at least two sticks per switch. - Grease all sliding surfaces of parts sparingly (innards of the switch body, shaft, contacts, rocker bolt pathway in the shaft) with plastic safe light grease. The goal of contact greasing is protection from moisture and oxygen that may re-deposit the patina again in time. Light grease won't interfere with low current low voltage electrical contact properties. - Re-assemble and exercise the switch. HTH, Best regards, Nenad  .

--
-----------------------------------------------------------------------
Glenn Little ARRL Technical Specialist QCWA LM 28417
Amateur Callsign: WB4UIV wb4uiv@... AMSAT LM 2178
QTH: Goose Creek, SC USA (EM92xx) USSVI LM NRA LM SBE ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"


Re: Another 7D20 attenuator question

Dallas Smith
 

Hi Håkan,
Get all the attenuator errors on boot, but all relays are good. As stated by my first post I believe that the substrate board is the cause.

I noticed that the 'A12 & A13 'substrate PCB' has tarnished relay contacts. they are a dull gray (lead?). I thought Tek gold plated PCB contacts for non corrosion and good contact resistance?
Shouldn't the contact pads be gold plated?


Re: Tek 465 Turns on, No Dot, No Trace

 

strictly that should refer to <https://groups.io/g/TekScopes>

David

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Stephen
Sent: 10 July 2020 14:43
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 465 Turns on, No Dot, No Trace

On Fri, Jul 10, 2020 at 02:28 AM, Albert Otten wrote:


Where do I find the archives? I’m new here.
Stephan, that's just short for "old messages at the Tekscopes website". A lot
of information and hints there. You also should know about Tekwiki ,
w140.com/tekwiki/wiki/Main_Page .
Albert
I see. Of course I know about TekWiki.
Thank you again.
Any advice regarding my other question About HV?


Re: Cleaning TM500 module pushbutton switches

Nenad Filipovic
 

On Fri, Jul 10, 2020 at 4:53 PM Colin Herbert via groups.io <colingherbert=
blueyonder.co.uk@groups.io> wrote:

Nenad,
You mention something you call "petroleum benzine". Though I am a retired
research chemist living in Britain, I have no idea of what this is and
others may not also. It _could_ be "petroleum ether", which I am familiar
with, but that comes in various boiling-point ranges and you wouldn't want
to use a high-boiling fraction; 60-40 is the most likely (boiling-range
between 60 and 40 degrees Centigrade/Celsius). Be cautious, this solvent is
very inflammable and not a little smelly. If you are actually thinking of
"benzene" (note the "e", not "i"), then I doubt that anyone in an EU
country would be able to buy that, as it is carcinogenic (causes cancer)
and is therefore controlled. Perhaps you could clarify?
Colin.
Hi Colin,

Yes indeed, I suspected that "petroleum benzine" might cause confusion, and
I'd be glad if we could clear it. The issue is that these damn chemicals
have notorious local names, and something that is quite wide known in one
country can have a completely different name in another, or not be
available at all.

To be honest, I am also not sure about my "petroleum benzine" true content,
but I strongly believe it's just a kind of petroleum ether. It is sold in
pharmacies and has the following uses and properties:
- often called "Benzinum medicinale" and can be looked up by that name in
Europe
- used in medicine as a solvent to clean skin and surfaces off greasy or
similar non-polar contaminants (commonly used to remove traces of adhesive
from skin after patches and bandages are taken off)
- generally used to remove greasy contaminants (as a non-polar solvent),
especially by watchmakers and jewelers
- is "moderately" volatile (e.g. less than acetone)
- is smelly, but certainly not very smelly or outright unpleasant (e.g.
acetone is much more pungent)
- certainly does not smell like benzEne (C6H6), I remember benzene smell
from chemistry classes as much "heavier" and more "oily" than this

These are the only links I found related to its technical properties:
http://www.gram.co.rs/ser/benzin_za_odmascivanje.htm
and
https://www.pharmawiki.ch/wiki/index.php?wiki=Wundbenzin

Due to its pharmaceutical use (application on skin) I was inclined to
believe it is not an aggressive substance. Throughout years of various uses
I can confirm that assumption, I find it mild on rubber and plastic
surfaces. I often use it to clean my photographic lenses, it does an
excellent job on fingerprints and all greasy stuff, evaporates without a
trace, and also no trace/damage on the surrounding plastic parts.

Best regards,
Nenad


Re: Tek 465 Turns on, No Dot, No Trace

 

What test equipment do you have access to? You might be able to make up a divider string to extend the range of a DMM to cover the 2500 volts needed to measure the cathode voltage. For example, if your DMM has a 10 meg input, then making up a 90 meg stack from 9 ten-meg, 1% resistors installed in a glass or plastic tube (Bic pen?) would give a X10 probe.

You would want to get that voltage right before adjusting any H & V adjustments.

Regards

On 7/10/2020 7:11 AM, Stephen wrote:
On Thu, Jul 9, 2020 at 03:48 PM, Tom Miller wrote:

Second, get the supplies working correctly. I suspect C1552 5000uF and
C1562 3000uF as being low capacity. Confirm by looking at the ripple on
the +5 and -8 test points.
Lots of ripple indeed!! You were right!!
I’m gonna change those 2 and report back.
I never would’ve thought that would have such a drastic impact on the trace.

Is there a way to check and adjust the -2450V HV without a HV probe??

Thanks again.

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: Another 7D20 attenuator question

 

On Tue, Jul 7, 2020 at 07:32 PM, Dallas Smith wrote:


My second 7D20 attenuators started acting up.
What is the actual problem ?
Early F/W's are known to sometimes cause false error(s) during startup.

/Håkan


Re: Cleaning TM500 module pushbutton switches

SCMenasian
 

In the US, benzene is one of many aromatic hydrocarbons. Aromatic hydrocarbons
are incompatible with many plastics; it can soften, or even dissolve, them. I would be very cautious about using "petroleum benzine" without testing it first. Isopropyl alcohol is much safer from both environmentally and from a compatibility viewpoiont.


Re: Cleaning TM500 module pushbutton switches

Renée
 

I have the same issue only with the plastic on plastic ( the actuator for finger poking to the to the outside world) is causing the sticking. they were cleaned with soap and water ( yes disassembled) to remove dirt and then ipa without success. suggestions?
I have used WD40 to soften grease for easier removal. leave it sit for a day or two, sometimes multiple applications...I try not to make it too messy.
thanks for the procedure, some things I had not considered, very helpful!
Renée

On 7/10/20 7:42 AM, Nenad Filipovic wrote:
On Fri, Jul 10, 2020 at 3:05 AM W1PJE <@W1PJE> wrote:
I have multiple TM500 modules that have developed sticky / intermittent
pushbutton switches (the square small ones). Is there a recommended cleaning procedure? I was going to do the standard use of Caig's DeOxit in a sparing manner, but perhaps there is a better way.
In some cases hard patina forms on contact surfaces and DeOxit can be ineffective or just a short term solution. Additionally, DeOxit cannot restore the original grease which is likely fully decomposed and dry due to age. In that case I use the following procedure to restore these without any desoldering: - Gain access, carefully uncouple and remove the pushbutton shaft. - Remove the clamp next to the spring, carefully remove the tiny parts (spring, tiny rocker bolt and its elastic support). - Carefully pull out the switch shaft at the back of the switch body - care must be taken to go slow and grip the two metal contacts (use tweezers) before they fully come out (otherwise they may fly off and get lost). Note (or take photo of) the orientation of contacts with respect to their slot in the shaft (the bend in the middle should be oriented away from the switch body). - If the switch is radio button type it will contain a "clutch" sliding plate that needs to be pushed to one side so the shaft could be released and removed. - Sometimes a PCB component may get in the way of shaft removal, I almost always find it easier to remove the offending component rather than the switch body. - If switch parts are clogged by ancient dried up grease, clean/wash everything (both plastic and metal parts) with a paintbrush in petroleum benzine (pharmaceutical grade, in Europe we get it in regular pharmacies; however most non-polar solvents which are not aggressive to plastic would do). Do not let the plastic parts sit in benzine for too long, all this can and should be done in just a few minutes. Let the clean parts dry. - Using a soft brass brush (I get these at dentist supply shops) gently scrub the patina off the active side of the metal contacts. Soft brass brush should not damage the contact plating that needs to be preserved. - Use cotton ear buds soaked first in petroleum benzine, then IPA to clean the internals of the switch body. I spend at least two sticks per switch. - Grease all sliding surfaces of parts sparingly (innards of the switch body, shaft, contacts, rocker bolt pathway in the shaft) with plastic safe light grease. The goal of contact greasing is protection from moisture and oxygen that may re-deposit the patina again in time. Light grease won't interfere with low current low voltage electrical contact properties. - Re-assemble and exercise the switch. HTH, Best regards, Nenad .


Re: New member with a currently-dead 2465

Siggi
 

Hey Vincent,

congrats on your 2465, I'm sure you'll get'er going again in no time.
Just to make sure though, is this a 2465 or a 2465A/B? There are important
differences between the three - notably the A5 board in the 2465B suffers
from surface mount capacitor leakage.

Inline.

Siggi

On Thu, Jul 9, 2020 at 9:05 PM Vincent Mallet <vmallet@...> wrote:

Question: how likely is it that the oscillator circuit has failed?

It happens.


Or could
there be an external factor preventing it from oscillating that I don't
see?
This can probably happen also :).
You may want to try and gently flex the board and maybe wiggle the
components involved. IIRC the crystal stands fairly proud, and so may
suffer vibration or shock damage. Best case you have a poor solder joint
somewhere.



My next step would be to pull the few components from the oscillating
circuit out so I can test them but I figured maybe I'd ask around if this
rang a bell first.
I don't remember oscillator death being a common issue.


Re: Cleaning TM500 module pushbutton switches

Colin Herbert
 

Nenad,
You mention something you call "petroleum benzine". Though I am a retired research chemist living in Britain, I have no idea of what this is and others may not also. It _could_ be "petroleum ether", which I am familiar with, but that comes in various boiling-point ranges and you wouldn't want to use a high-boiling fraction; 60-40 is the most likely (boiling-range between 60 and 40 degrees Centigrade/Celsius). Be cautious, this solvent is very inflammable and not a little smelly. If you are actually thinking of "benzene" (note the "e", not "i"), then I doubt that anyone in an EU country would be able to buy that, as it is carcinogenic (causes cancer) and is therefore controlled. Perhaps you could clarify?
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Nenad Filipovic
Sent: 10 July 2020 15:42
To: TekScopes@groups.io
Subject: Re: [TekScopes] Cleaning TM500 module pushbutton switches

On Fri, Jul 10, 2020 at 3:05 AM W1PJE <@W1PJE> wrote:

I have multiple TM500 modules that have developed sticky / intermittent
pushbutton switches (the square small ones). Is there a recommended
cleaning procedure? I was going to do the standard use of Caig's DeOxit in
a sparing manner, but perhaps there is a better way.
In some cases hard patina forms on contact surfaces and DeOxit can be
ineffective or just a short term solution. Additionally, DeOxit cannot
restore the original grease which is likely fully decomposed and dry due to
age. In that case I use the following procedure to restore these without
any desoldering:

- Gain access, carefully uncouple and remove the pushbutton shaft.
- Remove the clamp next to the spring, carefully remove the tiny parts
(spring, tiny rocker bolt and its elastic support).
- Carefully pull out the switch shaft at the back of the switch body - care
must be taken to go slow and grip the two metal contacts (use tweezers)
before they fully come out (otherwise they may fly off and get lost). Note
(or take photo of) the orientation of contacts with respect to their slot
in the shaft (the bend in the middle should be oriented away from the
switch body).
- If the switch is radio button type it will contain a "clutch" sliding
plate that needs to be pushed to one side so the shaft could be released
and removed.
- Sometimes a PCB component may get in the way of shaft removal, I almost
always find it easier to remove the offending component rather than the
switch body.
- If switch parts are clogged by ancient dried up grease, clean/wash
everything (both plastic and metal parts) with a paintbrush in petroleum
benzine (pharmaceutical grade, in Europe we get it in regular pharmacies;
however most non-polar solvents which are not aggressive to plastic would
do). Do not let the plastic parts sit in benzine for too long, all this can
and should be done in just a few minutes. Let the clean parts dry.
- Using a soft brass brush (I get these at dentist supply shops) gently
scrub the patina off the active side of the metal contacts. Soft brass
brush should not damage the contact plating that needs to be preserved.
- Use cotton ear buds soaked first in petroleum benzine, then IPA to clean
the internals of the switch body. I spend at least two sticks per switch.
- Grease all sliding surfaces of parts sparingly (innards of the switch
body, shaft, contacts, rocker bolt pathway in the shaft) with plastic safe
light grease. The goal of contact greasing is protection from moisture and
oxygen that may re-deposit the patina again in time. Light grease won't
interfere with low current low voltage electrical contact properties.
- Re-assemble and exercise the switch.

HTH,
Best regards,
Nenad


Re: Tektronix 2465b Boo Boo

Siggi
 

On Fri, Jul 10, 2020 at 6:32 AM James Theonas via groups.io <jamestheonas=
yahoo.com@groups.io> wrote:

What scale and test can I do to test calibration (Only as an indication of
course)? I don't actually know if scope is calibrated.
On the 2465 you can use the calibrator to (roughly) check the horizontal
(timing) accuracy of the scope. The calibrator's frequency is derived from
a crystal oscillator, and the calibrator's frequency tracks the time/DIV
setting of the scope to output 5 cycles across the CRT for most of the
range. By aligning the rising edge of the calibrator on the intersection of
a horizontal and the center vertical graticule line, you can see how far
you're out at the other end of the CRT.

Checking the vertical accuracy is harder - you need a signal generator that
can output something like a square wave with a well-defined, accurate
peak-to-peak voltage. The vertical deflection is only specified as +-2%
accurate for channel 1&2 (10% for 3&4), so your reference signal doesn't
need to be super accurate for a quick check.
The calibrator is specified to output 0.4V peak to peak, +-1%, so that'll
give you an indication of whether your 0.1V/DIV is good at least.

The service manual has a "Performance Verification" section, which details
how to validate that the scope is in all spec across the board. This is -
obviously - vastly more involved than a quick horizontal/vertical
deflection check.


Re: Cleaning TM500 module pushbutton switches

Nenad Filipovic
 

On Fri, Jul 10, 2020 at 3:05 AM W1PJE <@W1PJE> wrote:

I have multiple TM500 modules that have developed sticky / intermittent
pushbutton switches (the square small ones). Is there a recommended
cleaning procedure? I was going to do the standard use of Caig's DeOxit in
a sparing manner, but perhaps there is a better way.
In some cases hard patina forms on contact surfaces and DeOxit can be
ineffective or just a short term solution. Additionally, DeOxit cannot
restore the original grease which is likely fully decomposed and dry due to
age. In that case I use the following procedure to restore these without
any desoldering:

- Gain access, carefully uncouple and remove the pushbutton shaft.
- Remove the clamp next to the spring, carefully remove the tiny parts
(spring, tiny rocker bolt and its elastic support).
- Carefully pull out the switch shaft at the back of the switch body - care
must be taken to go slow and grip the two metal contacts (use tweezers)
before they fully come out (otherwise they may fly off and get lost). Note
(or take photo of) the orientation of contacts with respect to their slot
in the shaft (the bend in the middle should be oriented away from the
switch body).
- If the switch is radio button type it will contain a "clutch" sliding
plate that needs to be pushed to one side so the shaft could be released
and removed.
- Sometimes a PCB component may get in the way of shaft removal, I almost
always find it easier to remove the offending component rather than the
switch body.
- If switch parts are clogged by ancient dried up grease, clean/wash
everything (both plastic and metal parts) with a paintbrush in petroleum
benzine (pharmaceutical grade, in Europe we get it in regular pharmacies;
however most non-polar solvents which are not aggressive to plastic would
do). Do not let the plastic parts sit in benzine for too long, all this can
and should be done in just a few minutes. Let the clean parts dry.
- Using a soft brass brush (I get these at dentist supply shops) gently
scrub the patina off the active side of the metal contacts. Soft brass
brush should not damage the contact plating that needs to be preserved.
- Use cotton ear buds soaked first in petroleum benzine, then IPA to clean
the internals of the switch body. I spend at least two sticks per switch.
- Grease all sliding surfaces of parts sparingly (innards of the switch
body, shaft, contacts, rocker bolt pathway in the shaft) with plastic safe
light grease. The goal of contact greasing is protection from moisture and
oxygen that may re-deposit the patina again in time. Light grease won't
interfere with low current low voltage electrical contact properties.
- Re-assemble and exercise the switch.

HTH,
Best regards,
Nenad


Re: Tek 465 Turns on, No Dot, No Trace

Stephen
 

On Fri, Jul 10, 2020 at 02:28 AM, Albert Otten wrote:


Where do I find the archives? I’m new here.
Stephan, that's just short for "old messages at the Tekscopes website". A lot
of information and hints there. You also should know about Tekwiki ,
w140.com/tekwiki/wiki/Main_Page .
Albert
I see. Of course I know about TekWiki.
Thank you again.
Any advice regarding my other question About HV?


Re: Frequencies and voltages required to calibrate a 2400-series scope?

Roger Evans
 

Hi Siggi,

I am very interested to follow this thread since I might well need to recalibrate a 2465B and I am not keen on removing the NVRAM without some better de-soldering tools. I have no problem in providing the timing references from some home made synthesised generators and low frequency amplitude calibration from a PG506 but I don't have anything beyond a SG503 for constant amplitude at high frequency.

Regards,

Roger


Re: Tek 465 Turns on, No Dot, No Trace

Albert Otten
 

Where do I find the archives? I’m new here.
Stephan, that's just short for "old messages at the Tekscopes website". A lot of information and hints there. You also should know about Tekwiki , w140.com/tekwiki/wiki/Main_Page .
Albert


Re: Tek 465 Turns on, No Dot, No Trace

Stephen
 

On Thu, Jul 9, 2020 at 04:22 PM, Stephen wrote:


On Thu, Jul 9, 2020 at 03:48 PM, Tom Miller wrote:

A little searching the archives for 465 and 475 power supply tips would
help you.
Where do I find the archives? I’m new here.

Thanks