On Monday, October 23, 2017 at 8:12:33 PM UTC-4, k...@notreal.com wrote:
> On Mon, 23 Oct 2017 12:05:16 -0700 (PDT), mkoch583@gmail.com wrote:
> 
> >On Sunday, October 22, 2017 at 8:40:23 AM UTC-4, Michael Terrell wrote:
> >> mkoch583@gmail.com wrote:
> >> >
> >> > Ok group.  Worked on the 7633 and replaced a fuse on the first board you see when you remove the back cover.  This fixed a few things.  I now can get a trace , the CRT is nice and clear , and the flash that occurred every 8-9 seconds has stopped.   One problem left.  The trace is vertical instead of horizontal.   Still get a waveform from the function generator , but vertical.  Why is that?   Thanks for all your previous help.
> >> 
> >> 
> >>     Did you put the plugins back in their proper slots? The two left 
> >> slots are for Vertical, the right slot is Horizontal for the timebase.
> >
> >No Mike , I don't think the plug-ins are in those particular slots.  I'll check and make the appropriate swaps.  Does it matter if , in the two left slots , where the dual trace amplifier or the curve tracer go?   Thanks
> 
> The vertical amplifiers can go in either the left slot or the center
> slot.  The horizontal amplifier has to go in the right slot, so if you
> have a curve tracer it has to go into the *right* two slots (it
> controls the horizontal and it controls the vertical ;-).
> 
> If you have two vertical amplifiers, you can put them in the center
> and right slots and do X-Y.  I believe a timebase will work in the
> center or left slot but it doesn't make much sense (the trace will be
> vertical).

  Ok gentlemen , all is well at the AB8CQ workbench. The 7633 is percolating nicely after I put all the plug-ins in the right place.  I'd like to thank all of you for your input and advice.  I'll make sure to come back to this group in case I have any other issues.   Thanks again.

     Mike

On Mon, 23 Oct 2017 12:05:16 -0700 (PDT), mkoch583@gmail.com wrote:

>On Sunday, October 22, 2017 at 8:40:23 AM UTC-4, Michael Terrell wrote:
>> mkoch583@gmail.com wrote:
>> >
>> > Ok group.  Worked on the 7633 and replaced a fuse on the first board you see when you remove the back cover.  This fixed a few things.  I now can get a trace , the CRT is nice and clear , and the flash that occurred every 8-9 seconds has stopped.   One problem left.  The trace is vertical instead of horizontal.   Still get a waveform from the function generator , but vertical.  Why is that?   Thanks for all your previous help.
>> 
>> 
>>     Did you put the plugins back in their proper slots? The two left 
>> slots are for Vertical, the right slot is Horizontal for the timebase.
>
>No Mike , I don't think the plug-ins are in those particular slots.  I'll check and make the appropriate swaps.  Does it matter if , in the two left slots , where the dual trace amplifier or the curve tracer go?   Thanks

The vertical amplifiers can go in either the left slot or the center
slot.  The horizontal amplifier has to go in the right slot, so if you
have a curve tracer it has to go into the *right* two slots (it
controls the horizontal and it controls the vertical ;-).

If you have two vertical amplifiers, you can put them in the center
and right slots and do X-Y.  I believe a timebase will work in the
center or left slot but it doesn't make much sense (the trace will be
vertical).

On Sunday, October 22, 2017 at 8:40:23 AM UTC-4, Michael Terrell wrote:
> mkoch583@gmail.com wrote:
> >
> > Ok group.  Worked on the 7633 and replaced a fuse on the first board you see when you remove the back cover.  This fixed a few things.  I now can get a trace , the CRT is nice and clear , and the flash that occurred every 8-9 seconds has stopped.   One problem left.  The trace is vertical instead of horizontal.   Still get a waveform from the function generator , but vertical.  Why is that?   Thanks for all your previous help.
> 
> 
>     Did you put the plugins back in their proper slots? The two left 
> slots are for Vertical, the right slot is Horizontal for the timebase.

No Mike , I don't think the plug-ins are in those particular slots.  I'll check and make the appropriate swaps.  Does it matter if , in the two left slots , where the dual trace amplifier or the curve tracer go?   Thanks

mkoch583@gmail.com wrote:
>
> Ok group.  Worked on the 7633 and replaced a fuse on the first board you see when you remove the back cover.  This fixed a few things.  I now can get a trace , the CRT is nice and clear , and the flash that occurred every 8-9 seconds has stopped.   One problem left.  The trace is vertical instead of horizontal.   Still get a waveform from the function generator , but vertical.  Why is that?   Thanks for all your previous help.


    Did you put the plugins back in their proper slots? The two left 
slots are for Vertical, the right slot is Horizontal for the timebase.

On Sat, 21 Oct 2017 13:05:38 -0700, mkoch583 wrote:

> Ok group.  Worked on the 7633 and replaced a fuse on the first board you
> see when you remove the back cover.  This fixed a few things.  I now can
> get a trace , the CRT is nice and clear , and the flash that occurred
> every 8-9 seconds has stopped.   One problem left.  The trace is
> vertical instead of horizontal.   Still get a waveform from the function
> generator , but vertical.  Why is that?   Thanks for all your previous
> help.
> 
>      Mike

Try fiddling with the timebase controls. Some scopes (notably Philips) 
have exceptionally complicated timebase options. Can't recall what yours 
is off-hand, sorry.



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On Thursday, October 19, 2017 at 4:07:13 AM UTC-4, Tauno Voipio wrote:
> On 18.10.17 21:33, mkoch583@gmail.com wrote:
> > On Tuesday, October 17, 2017 at 9:00:51 PM UTC-4, jurb...@gmail.com wrote:
> >> On most Teks with plugins if you unplug the vertical ones you should get a line across the screen. Just leave the horizontal in. Put it o auto. If that doesn't work switch it to external input. If that doesn't work remove the horizontal as well, which on some will result in a spot in the center of the screen.
> >>
> >> Also good test points are the deflection plates, which are usually on the sides of the neck of the CRT. You can tell the vertical ad horizontal pairs. The voltages should be close on each element of a pair but not necessarily pair to pair.
> >>
> >> Schematics are available on the net, if the voltages match but are all off from what the print says look to the power supply. Of course if removing any plugin restores the trace or spot, look at that first.
> >>
> >> It is a bit rough to measure the high voltage directly but there are telling test points, usually the focus control. Good luck with it. If it does turn out to be one of the plugins, they are available. They are not scrap prices yet so I guess there is a significant number of these old beasts that work.
> > 
> > There are three plug-ins on this unit ( none of which are just horizontal or vertical ): curve tracer , dual trace amplifier supplying the channel 1 and channel 2 inputs , and a dual time base.  I pulled the curve tracer. No dice.  I swapped the dual trace amp with the dual time base. No good. I cleaned all of the terminals on the back of each plug in. I even pulled out all of the plug-ins.  No luck.
> >    There are no inputs on the main oscilloscope itself so I have to rely on the dual trace amp plug-in to input a signal.
> >    I've downloaded a copy of the user and service manuals so I'm going to look it over.  Thank you all for your time.
> >   ( PS )  I also have a BK Precision scope that works well but it's only 10 MHz bandwidth.  I really need the 100 MHz for rf work.
> 
> 
> The dual time base is horizontal, and the dual trace amplifier is
> (mostly) vertical. The curve tracer is probably both.
> 
> -- 
> 
> -TV

Ok group.  Worked on the 7633 and replaced a fuse on the first board you see when you remove the back cover.  This fixed a few things.  I now can get a trace , the CRT is nice and clear , and the flash that occurred every 8-9 seconds has stopped.   One problem left.  The trace is vertical instead of horizontal.   Still get a waveform from the function generator , but vertical.  Why is that?   Thanks for all your previous help.

     Mike 

On Thursday, October 19, 2017 at 4:07:13 AM UTC-4, Tauno Voipio wrote:
> On 18.10.17 21:33, mkoch583@gmail.com wrote:
> > On Tuesday, October 17, 2017 at 9:00:51 PM UTC-4, jurb...@gmail.com wrote:
> >> On most Teks with plugins if you unplug the vertical ones you should get a line across the screen. Just leave the horizontal in. Put it o auto. If that doesn't work switch it to external input. If that doesn't work remove the horizontal as well, which on some will result in a spot in the center of the screen.
> >>
> >> Also good test points are the deflection plates, which are usually on the sides of the neck of the CRT. You can tell the vertical ad horizontal pairs. The voltages should be close on each element of a pair but not necessarily pair to pair.
> >>
> >> Schematics are available on the net, if the voltages match but are all off from what the print says look to the power supply. Of course if removing any plugin restores the trace or spot, look at that first.
> >>
> >> It is a bit rough to measure the high voltage directly but there are telling test points, usually the focus control. Good luck with it. If it does turn out to be one of the plugins, they are available. They are not scrap prices yet so I guess there is a significant number of these old beasts that work.
> > 
> > There are three plug-ins on this unit ( none of which are just horizontal or vertical ): curve tracer , dual trace amplifier supplying the channel 1 and channel 2 inputs , and a dual time base.  I pulled the curve tracer. No dice.  I swapped the dual trace amp with the dual time base. No good. I cleaned all of the terminals on the back of each plug in. I even pulled out all of the plug-ins.  No luck.
> >    There are no inputs on the main oscilloscope itself so I have to rely on the dual trace amp plug-in to input a signal.
> >    I've downloaded a copy of the user and service manuals so I'm going to look it over.  Thank you all for your time.
> >   ( PS )  I also have a BK Precision scope that works well but it's only 10 MHz bandwidth.  I really need the 100 MHz for rf work.
> 
> 
> The dual time base is horizontal, and the dual trace amplifier is
> (mostly) vertical. The curve tracer is probably both.
> 
> -- 
> 
> -TV

Thanks for the help.  Very much appreciated.

On 18.10.17 21:33, mkoch583@gmail.com wrote:
> On Tuesday, October 17, 2017 at 9:00:51 PM UTC-4, jurb...@gmail.com wrote:
>> On most Teks with plugins if you unplug the vertical ones you should get a line across the screen. Just leave the horizontal in. Put it o auto. If that doesn't work switch it to external input. If that doesn't work remove the horizontal as well, which on some will result in a spot in the center of the screen.
>>
>> Also good test points are the deflection plates, which are usually on the sides of the neck of the CRT. You can tell the vertical ad horizontal pairs. The voltages should be close on each element of a pair but not necessarily pair to pair.
>>
>> Schematics are available on the net, if the voltages match but are all off from what the print says look to the power supply. Of course if removing any plugin restores the trace or spot, look at that first.
>>
>> It is a bit rough to measure the high voltage directly but there are telling test points, usually the focus control. Good luck with it. If it does turn out to be one of the plugins, they are available. They are not scrap prices yet so I guess there is a significant number of these old beasts that work.
> 
> There are three plug-ins on this unit ( none of which are just horizontal or vertical ): curve tracer , dual trace amplifier supplying the channel 1 and channel 2 inputs , and a dual time base.  I pulled the curve tracer. No dice.  I swapped the dual trace amp with the dual time base. No good. I cleaned all of the terminals on the back of each plug in. I even pulled out all of the plug-ins.  No luck.
>    There are no inputs on the main oscilloscope itself so I have to rely on the dual trace amp plug-in to input a signal.
>    I've downloaded a copy of the user and service manuals so I'm going to look it over.  Thank you all for your time.
>   ( PS )  I also have a BK Precision scope that works well but it's only 10 MHz bandwidth.  I really need the 100 MHz for rf work.


The dual time base is horizontal, and the dual trace amplifier is
(mostly) vertical. The curve tracer is probably both.

-- 

-TV

On Tuesday, October 17, 2017 at 9:00:51 PM UTC-4, jurb...@gmail.com wrote:
> On most Teks with plugins if you unplug the vertical ones you should get a line across the screen. Just leave the horizontal in. Put it o auto. If that doesn't work switch it to external input. If that doesn't work remove the horizontal as well, which on some will result in a spot in the center of the screen. 
> 
> Also good test points are the deflection plates, which are usually on the sides of the neck of the CRT. You can tell the vertical ad horizontal pairs. The voltages should be close on each element of a pair but not necessarily pair to pair. 
> 
> Schematics are available on the net, if the voltages match but are all off from what the print says look to the power supply. Of course if removing any plugin restores the trace or spot, look at that first. 
> 
> It is a bit rough to measure the high voltage directly but there are telling test points, usually the focus control. Good luck with it. If it does turn out to be one of the plugins, they are available. They are not scrap prices yet so I guess there is a significant number of these old beasts that work.

There are three plug-ins on this unit ( none of which are just horizontal or vertical ): curve tracer , dual trace amplifier supplying the channel 1 and channel 2 inputs , and a dual time base.  I pulled the curve tracer. No dice.  I swapped the dual trace amp with the dual time base. No good. I cleaned all of the terminals on the back of each plug in. I even pulled out all of the plug-ins.  No luck.
  There are no inputs on the main oscilloscope itself so I have to rely on the dual trace amp plug-in to input a signal.
  I've downloaded a copy of the user and service manuals so I'm going to look it over.  Thank you all for your time.
 ( PS )  I also have a BK Precision scope that works well but it's only 10 MHz bandwidth.  I really need the 100 MHz for rf work.

On Tue, 17 Oct 2017 17:39:46 -0700, mkoch583 wrote:

> On Tuesday, October 17, 2017 at 5:20:14 PM UTC-4, Cursitor Doom wrote:
>> On Tue, 17 Oct 2017 12:53:05 -0700, mkoch583 wrote:
>> 
>> > I've recently gotten hold of a Tektronix 7633 oscilloscope but can't
>> > seem to get a trace or any kind of waveform on the crt.   Was
>> > wondering if I'm doing something wrong , not doing something right ,
>> > or is the scope in need of repair?  Is the repair complex ( I know my
>> > way around a soldering iron ) or should I just sell it for parts.
>> >   It came with three plug-ins : Dual trace amplifier , curve tracer ,
>> >   and dual time base.
>> >   Tried two different function generators and the output from my
>> >   4-watt transceiver.  No joy.  Any help would be greatly
>> >   appreciated.
>> >    Thank you.
>> 
>> Are you familiar with scopes at all? Any useful answer will need to be
>> based on your degree of experience with them. Have you owned CRT-based
>> scopes before?
>> 
>> 
>> 
>> --
>> This message may be freely reproduced without limit or charge only via
>> the Usenet protocol. Reproduction in whole or part through other
>> protocols, whether for profit or not, is conditional upon a charge of
>> GBP10.00 per reproduction. Publication in this manner via non-Usenet
>> protocols constitutes acceptance of this condition.
> 
> I'm not an expert with scopes but , as I'm wishing to get back into
> homebrewing radio gear , I think one would be a very useful instrument
> to have on the bench.  Looking at my original post , I suppose it's
> obvious that I've got a lot to learn , but this is something that I want
> to pursue in retirement ( I'm 64 ).
>   About 15 years ago I owned a Sencore scope but sold it when I moved to
>   a new house.  Never really learned how to use it.
>   But as I said , just trying to get at least a horizontal line on the
>   crt.  Then I can figure it out from there.  Thanks.
> 
>     Mike   AB8CQ

Things to check (being extremely careful to not touch any cathode circuits
until/unless you've verified that cathode voltage is discharged - it's 
probably around -2kV and enough current capacity to kill!):

* make sure filament voltage is present.  can you see any glow? is 
filament open?

* verify that Z-axis isn't too negative relative to cathode (will 
extinguish any beam).  This potential is used to blank between sweeps 
so may be hard to measure.  If your 'scope has an X-Y mode that might
turn it on for a long time and allow use of a DMM.

* is cathode voltage as negative as manual indicates?

* verify that V,H deflection plates aren't wildly off.  You could
disconnect all 4 plate pins, connect to ground - do you get a dot 
mid-screen? 

My memory has faded.  Is this the variable persistence model?  That
would complicate matters.