Date   

Re: Stuck switches on 453

greenboxmaven
 

In addition to the volatiles evaporating, the grease or oil can oxidize into varnish. This is greatly enhanced by moisture. I have had great results for many years using synthetic engine oil such as Mobil 1 0W-15 and heat to liquify the varnish. Put a few drops of the oil on the shaft and bushing, them heat the shaft where it goes into the bushing with a soldering iron until the oil is sizzling, add more oil as needed to maintain the heat bridge to the shaft and bushing. Remove any plastic couplings, gears, or knobs that could be damaged by the heat before you start. Work the shaft back and forth carefully until it frees up, be patient, if you don't get results at first, be sure there is a drop of oil on the shaft where it enters the bushing and let it cool. It may require a few heating-cooling cycles with the oil applied before it frees up, once it does, flush the oil and crud out thoroughly and re-lubricate with the synthetic oil. Then, use a contact cleaner of your choice for the pot or switch contacts.

Bruce Gentry, KA2IVY

On 8/1/20 12:02 PM, Gary Robert Bosworth wrote:
So often, it is the grease that was used as a lubricant and the volatiles
evaporated leaving a dried up paste.

On Sat, Aug 1, 2020, 08:58 Richard P via groups.io <wb5nen=
yahoo.com@groups.io> wrote:

David (and others):

Yes, my problem is the same as yours: The variable knobs on Ch. 1 and 2
Volts/Div are frozen, and are stuck in the uncalibrated mode. I???ve tried
various compounds...some for switches, some for pots, but no joy. Colorful
Anglo-Saxon expressions haven???t helped, either. Just NOT going to budge,
either one of them. Don???t know if it???s switches or pots that are binding.

But, since I mostly want this scope in Calibrated mode (and not
Uncalibrated, where it is locked-up now), I???m thinking I will just bypass
the switches and live with it. That???s what I???m thinking.

R




Re: Why would you do this?

 

Hi Snapdiode,
Given the condition of the front cover you can see this manual was heavily used so you can assume the spine also shows comparable wear and tear. In addition to that, these comb bindings become brittle with age and the plastic changes from white to light yellow. If it was in a smoking environment (quite common years ago) that will add even more deterioration to it. I think it is expecting too much to assume anything about the spine including if it is still there at all.
If the spine is cracked or missing entirely it is easy to find an office supply store that can put a new comb binding on it for you. The price is pretty insignificant to replace a comb binding. I can do it for you if you want.
I don't think he is trying to hide anything. It is probably more likely the spine was not important enough to the seller to include in the photo.
As you indicated the price preferredgamingandtrade is asking is quite reasonable. At this price he isn't making any money with this auction. So why would he want to take additional photos for a manual he is selling for $15.00. I thinking he is doing any member who has a P6042 probe a favor by offering it at all. I would buy it in a heartbeat if I didn't have it already. Most people would toss this in the recycle bin rather go to all the trouble to list it.
Dennis Tillman W7pF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of snapdiode via groups.io
Sent: Saturday, August 01, 2020 9:30 AM
To: TekScopes@groups.io
Subject: [TekScopes] Why would you do this?

https://www.ebay.ca/itm/P6042-Probe-Manual-B-7/174057498026?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20180105095853%26meid%3D275a9bf791574af0888ffaf1f52182aa%26pid%3D100903%26rk%3D1%26rkt%3D20%26mehot%3Dnone%26sd%3D174057498026%26itm%3D174057498026%26pmt%3D1%26noa%3D1%26pg%3D2510209&_trksid=p2510209.c100903.m5276

As we can see the photo of the manual is cropped to hide the spine and cover edge.

I assume the spine is totally cracked and wrecked and the edge is tattered.

But the price is OK, all I want is an answer from the seller, and I've been messaging the seller for a week.

Does anyone have a physical P6042 manual for sale for less than 20$ and reasonable shipping?





--
Dennis Tillman W7pF
TekScopes Moderator


Why would you do this?

snapdiode
 

https://www.ebay.ca/itm/P6042-Probe-Manual-B-7/174057498026?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20180105095853%26meid%3D275a9bf791574af0888ffaf1f52182aa%26pid%3D100903%26rk%3D1%26rkt%3D20%26mehot%3Dnone%26sd%3D174057498026%26itm%3D174057498026%26pmt%3D1%26noa%3D1%26pg%3D2510209&_trksid=p2510209.c100903.m5276

As we can see the photo of the manual is cropped to hide the spine and cover edge.

I assume the spine is totally cracked and wrecked and the edge is tattered.

But the price is OK, all I want is an answer from the seller, and I've been messaging the seller for a week.

Does anyone have a physical P6042 manual for sale for less than 20$ and reasonable shipping?


Re: OT - Any interest in starting a Tektronix Logic Analyzer Group? (with added bonus question!)

jslcanuck
 

Noting that I'm replying nearly ten years after this posting, yes, an analyzer group is needed,
and I really don't think it should be Tek-specific. In fact, there are *already* various analyzer
groups here (both Tek and non-) that haven't seen a post. It's going to take a small group
of people (or maybe just one who's kind of obsessively nuts) to give one a proper launch. I
say open it up to Tek, HP, Arium, and whatever else anyone wants to pour in. In my experience
over in the Data I/O group, people and the potential for discussion is not enough; a critical mass
of useful files (docs and software) is what makes the difference and brings active users.

Bonus added question:

I have a TLA 510/520 I want to press into use. I have the 92C96 acquisition board, cable,
and leads - all the way to the individual two-pin signal (+gnd) leads meant to be plugged into
header pins on the target. That's where my problem starts - I need grabber clips (EZ-Hook,
KlipChip, etc.), but the grabbers only have a single pin and the probe cable won't fit onto
them. In the manual for this thing (under "optional accessories") they describe:

p/n 020-2108-00: Six 8-channel lead sets, 12 Y-cables, 72 KlipChip Adapters

Are these "Y-cables" little two-wire splitters that go between the probe tip and the grabber?


Re: Stuck switches on 453

Gary Robert Bosworth
 

So often, it is the grease that was used as a lubricant and the volatiles
evaporated leaving a dried up paste.

On Sat, Aug 1, 2020, 08:58 Richard P via groups.io <wb5nen=
yahoo.com@groups.io> wrote:

David (and others):

Yes, my problem is the same as yours: The variable knobs on Ch. 1 and 2
Volts/Div are frozen, and are stuck in the uncalibrated mode. I’ve tried
various compounds...some for switches, some for pots, but no joy. Colorful
Anglo-Saxon expressions haven’t helped, either. Just NOT going to budge,
either one of them. Don’t know if it’s switches or pots that are binding.

But, since I mostly want this scope in Calibrated mode (and not
Uncalibrated, where it is locked-up now), I’m thinking I will just bypass
the switches and live with it. That’s what I’m thinking.

R




Re: Stuck switches on 453

Richard P
 

David (and others):

Yes, my problem is the same as yours: The variable knobs on Ch. 1 and 2 Volts/Div are frozen, and are stuck in the uncalibrated mode. I’ve tried various compounds...some for switches, some for pots, but no joy. Colorful Anglo-Saxon expressions haven’t helped, either. Just NOT going to budge, either one of them. Don’t know if it’s switches or pots that are binding.

But, since I mostly want this scope in Calibrated mode (and not Uncalibrated, where it is locked-up now), I’m thinking I will just bypass the switches and live with it. That’s what I’m thinking.

R


Re: Tektronix 2230

satbeginner
 

Hello Saroj,

I was busy the past few days, hence my late reaction...

C907 being not there (open connection or broken capacitor) will definitely be of influence to the switchers behaviour.
I see in your pictures (especially TP45 !) a extra spikes in between the pulses I would not expect to see, which are also not in the service manual.

This could be related to a wrongly chosen reference point for the groundlead of the testprobe.
I looked in the 2232 Service manual and the 2230, and I found them not quite clear in describing where the ground lead of your probe should go, so I checked the 2215A service manual too, and I found that better.
In the 2215A manual next to each testpoint it is clearly stated where the ground lead should go.
I will add that page of the 2251A manual to the album with your pictures.

Added in your album: https://groups.io/g/TekScopes/album?id=250384


In the 2215A and 2230 service manual you can see the extra spikes should not be there.

I would be very interested in the TP at the Gate of the switching FET. (TP38 in the 2215A SM, TP45 in the 2230 SM), that should use TP940 as ground reference.
Beware! your 2230 scope under test must be running using the isolation transformer for these measurements!

I also found the amplitudes I could read from your pictures quite different from the ones in the service manual.

For now I would first concentrate on the power supply, and look at the vertical deflection later.

Stay safe,

Leo


Re: DC503 Not Working

Stephen
 

On Sat, Aug 1, 2020 at 03:34 AM, Roger Evans wrote:


My DC503 also has nothing connected at the lower of the two points in your
picture. On my board there are four of these holes in a row with no wires or
components attached, partky hidden by the shaft of the function switch. They
are 'vias' used to transfer a PCB trace to the opposite side of the board for
routing purposes. There is another row of 7 similar vias towards the
connector end of the same board.

Roger

Interesting. The schematic shows pin 12 connected to a switch....


Re: DC503 Not Working

Roger Evans
 

My DC503 also has nothing connected at the lower of the two points in your picture. On my board there are four of these holes in a row with no wires or components attached, partky hidden by the shaft of the function switch. They are 'vias' used to transfer a PCB trace to the opposite side of the board for routing purposes. There is another row of 7 similar vias towards the connector end of the same board.

Roger


Re: DC503 Not Working

Stephen
 

I always discover new stuff...
It seems the pin, I think, 12? of U354 Is connected to nothing.... But I pretty sure it should be...

See pict: https://groups.io/g/TekScopes/photo/250733/0?p=Created,,,20,2,0,0

There is continuity between these to points, but nothing is connected...
I’m not sure if this is related to my display issue, but I’m sure it’s not right.
Does any have one of these and tell me what should be there, if anything?

Thanks.


Re: Stuck switches on 453

Dale H. Cook
 

On 7/31/2020 10:20 AM, JR wrote:

I have tried turning the Scope where the Potentiometer Shaft is Vertical
and place a Few Drops of Deoxit on the Shaft ...
DeoxIT is not intended for potentiometers - it is for switches. Caig FaderLube is intended for potentiometers and other controls.
--
Dale H. Cook, GR/HP/Tek Collector, Roanoke/Lynchburg, VA
https://plymouthcolony.net/starcity/radios/


Re: Tektronix 2246 flickering screen, ch2 not working.

grusus@...
 

After taking some break in troubleshooting this scope, I got back to it.

After analysing service manual I got to the point that sth is messed up with clock/timing.

I think this is corelated with visible retrace.

Checked clock signal around U2409, U2508, U2507 - all seems fine. I am little concern about timer reset signal (+1VDC, no ac - only 8Mhz ripple from main clock - I don't know how it should look like), and INTR signal - also only dc no ac.

Today I made small experiment and dissconnected RO BLANK (R2419). Readouts are much brighter, grid dot is fully present, readouts are less blurry and more stable.
On Video I am connecting and dissconneting R2419.

https://photos.app.goo.gl/341Lxitp8DYbE9R97

That is why I am almost certain that there is some timing/interrupt/clock issue in this scope. It blanks when it shouldn't,

Can anybody give a hint what to check next? How to address this problem?


Re: Tektronix 2230

Saroj Pradhan
 

Hi Satbeginner
I measured some wave froms.
I have attached some snapshot in the same link that you created for me.
You suggested me to measure the gate voltage. Is the voltage to be measured
is with respect tp940?.
I have another issue with this scope.
Both the beam deflects applying input to just single channel. Text swings
vertically while applying signal to the oscilloscope.
Thanks
Saroj



On Fri, Jul 31, 2020, 6:18 PM Saroj Pradhan via groups.io <sarojman.Pradhan=
gmail.com@groups.io> wrote:

Hi
Satbeginner

Hope, every thing is fine with you.
I am ready with isolation transformer.
I had to build myself one. It was a tedious task, Because I do not have
proper winding machine. I will take the measurement tomorrow.
By the way, now the oscilloscope can be put on for more than 20 minutes. I
did not try for more than 20 minutes. What I noticed is the poor terminal
contact of C907. My question is :What happens if C907 terminal is open?
Right now, I have put irf830 for q9070 and ug2d(25ns recovery time)
Ug2d does not meet the specification for voltage requirement. Ug2d is rated
for 200v.
I am in much more difficult situation to acquire proper replacement part.
All option I have is either salvage the
component from old board or look in the local market. If I am lucky I can
find
some component in local market.
One thing more I have chacked the temperature at heatsink of q9070. In 20
minutes time it reached upto 70 degree Celsius.
Thanks
Saroj





On Fri, Jul 17, 2020, 10:28 AM Saroj Pradhan via groups.io
<sarojman.Pradhan=gmail.com@groups.io> wrote:

Hi Satbeginner
Right now I am looking for the transformer. I will get back when I find
one.
Thanks
Saroj

On Fri, Jul 17, 2020, 10:05 AM Saroj Pradhan via groups.io
<sarojman.Pradhan=gmail.com@groups.io> wrote:

Hi
Yes the transformer is not isolated its a tapped primary.
I need to find another one.
Thanks Harvey








Re: 2432A Chan Delay adjustment

Colin Herbert
 

I think you'll find that there is a switch to the right of the AMPLITUDE rotary switch which looks a little like the "AC/GND/DC" switches on many Tek scopes. This switch is marked STD AMPL/FAST RISE/HIGH AMPL and when put in the FAST RISE position the PERIOD led lights up and the AMPLITUDE led extinguishes. The controls on the greyed section of the front panel become operational and you can select the PERIOD and PULSE AMPLITUDE. The outputs are two BNCs; either fall or rise. It should all be in the manual.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Peter K via groups.io
Sent: 31 July 2020 10:01
To: TekScopes@groups.io
Subject: [TekScopes] 2432A Chan Delay adjustment

My scope 2432A gave a 9300 Trigs/Repet fail error some time ago. It works fine but I decided to fix it.
I did do a cold start and self cal passed. Also Atten Gain and Trigger adjustments passed.
My difficulty is Chan Delay adjustment. The Service manual (page 5-13) just said: “Set the Calibration Generator for a FAST RISE output”. But it is not clear what frequency and amplitude (Vp-p) is expected by the scope. I don’t have Calibration Generator PG 506. I read the manual on PG506, but it did not become clear.
I know that for non-critical applications the external calibration can be ignored, but I just won’t to remove the annoying inscription on start up
Any help would be greatly appreciated

Thanks, Peter.


Re: TM 500 Power Module Tester and Utility Power Supply

Dave Casey
 

There are already photos on the TekWiki page for this plugin showing
exactly what you're asking for. The unit shown is of identical construction
to mine (down to the sharpie labeling of the PWB part number and the
hand-scribed number in the soldermask above it).

Dave Casey

On Sat, Aug 1, 2020 at 1:15 AM Bill Perkins <sales@...> wrote:

I have one that was made by Tek (has a Tek serial number). It has a
single,
purpose built Tek PWB in it, which has been numbered "670-8715-00" in
Sharpie. The two trimmers in mine are Bourns 386 series. All the front
panel controls and I/O are connected to the PWB with hookup wire
(including
the Scope output). The board is laid out such that all these connection
points are near the front panel end of the PWB, and they all appear to
be
labeled in the etch layer.

Dave Casey
Would you mind pulling the covers off and taking a few photos of each
side of the PCB and both sides of the front panel?

I'm interested in building one myself too.

Thanks!
Jared
Likewise . . .

Bill




2432A Chan Delay adjustment

Peter K
 

My scope 2432A gave a 9300 Trigs/Repet fail error some time ago. It works fine but I decided to fix it.
I did do a cold start and self cal passed. Also Atten Gain and Trigger adjustments passed.
My difficulty is Chan Delay adjustment. The Service manual (page 5-13) just said: “Set the Calibration Generator for a FAST RISE output”. But it is not clear what frequency and amplitude (Vp-p) is expected by the scope. I don’t have Calibration Generator PG 506. I read the manual on PG506, but it did not become clear.
I know that for non-critical applications the external calibration can be ignored, but I just won’t to remove the annoying inscription on start up
Any help would be greatly appreciated

Thanks, Peter.


Re: TM 500 Power Module Tester and Utility Power Supply

Bill Perkins
 

I have one that was made by Tek (has a Tek serial number). It has a single,
purpose built Tek PWB in it, which has been numbered "670-8715-00" in
Sharpie. The two trimmers in mine are Bourns 386 series. All the front
panel controls and I/O are connected to the PWB with hookup wire (including
the Scope output). The board is laid out such that all these connection
points are near the front panel end of the PWB, and they all appear to be
labeled in the etch layer.

Dave Casey
Would you mind pulling the covers off and taking a few photos of each side of the PCB and both sides of the front panel?
I'm interested in building one myself too.
Thanks!
Jared
Likewise . . .

Bill


Re: DC503 Not Working

Stephen
 

On Mon, Jul 27, 2020 at 07:06 AM, Colin Herbert wrote:


I think you are getting terms a bit confused. Zero resistance _is_ a short.
Perhaps you intended to write "infinite resistance"? Easily done.
Colin.
Yes, you’re absolutely right. What I awkwardly meant to say is that I “read” nothing on the meter, and that the continuity tester didn’t beep.

Thanks for correcting me.


Re: Stuck switches on 453

dabono@...
 

I came across a similar problem recently on a T922. In my case, the variable knobs for the channel 1 and channel 2 Volts/Div were frozen (and the shaft coupling on the CH2 knob was broken, probably from somebody trying to force it).

I was able to get them working again by spraying a little contact cleaner where the potentiometer shaft goes into the "sleeve" on the potentiometer body, and gradually turning them back and forth several times. They were very stiff at first, but eventually needed less force to turn them, and they'd rotate a bit further each time. I didn't need to do anything to the switches behind the pots.

I don't know if you tried contact cleaner in that particular spot - if not, it's worth a try.

Good luck!
David


Re: TM 500 Power Module Tester and Utility Power Supply

Jared Cabot
 

On Sat, Aug 1, 2020 at 12:39 PM, Dave Casey wrote:


I have one that was made by Tek (has a Tek serial number). It has a single,
purpose built Tek PWB in it, which has been numbered "670-8715-00" in
Sharpie. The two trimmers in mine are Bourns 386 series. All the front
panel controls and I/O are connected to the PWB with hookup wire (including
the Scope output). The board is laid out such that all these connection
points are near the front panel end of the PWB, and they all appear to be
labeled in the etch layer.

Dave Casey
Would you mind pulling the covers off and taking a few photos of each side of the PCB and both sides of the front panel?

I'm interested in building one myself too.


Thanks!
Jared