Test Equipment Anonymous (TEA) group therapy thread

[Addicted2AnalogTek]

FedEx delivery today. A very dirty but complete 485. Advert was parts/not working and priced reasonable. And they weren't kidding. It's totally dead. The PSU doesn't even tick. But that doesn't matter. It's going to be a sacrifice...a parts mule. Going to swap out the trigger board with the 485 that does power up, but drove me nuts for weeks trying to figure out the trigger issue.

I'll post pictures of the surgery.




And.....the new trigger preset pot for the 535A will arrive today. Never bored here. 

My money is on this:  you'll end up replacing the filter caps on the new-to-you 485, it'll require minimal repairs, and you'll end up hunting for another parts mule 485 because you wont want to sacrifice the working one for the other one. Only time will tell, though....   

I have two 485's and a dedicated parts unit (no case, already tried to get it running and think the CRT is toast, anyway...), but I lack the time as I have to finish remodeling the current project house in 70 days and it's a solo mission...  I've got a 12' long shelving unit that is literally filled with Tek goodies to restore once I have some time... Oh, and a kitten that loves climbing all over it 

[Addicted2AnalogTek]

Uh...mnem

flu like symptoms?? 

what continent you on??

I just spoke with a friend that spoke with another friend that lives in China, and apparently the patients at the hospitals are getting pissed off and spitting on the hospital staff..... this stuff is destined to get significantly worse.... 

[worsthorse]

I am surprised there weren't more responses given the general level of teklust around here...  My current wish list looks like this:

blah blah blah...

I'm not a big fan of the 7834, especially the older ones with the 154-0745-00 CRT, which I find murky and ugly.  If you must have storage, the 7934 is much better.  Any storage mainframe will be greatly inferior to non-storage in trace brightness.

(Note: Plugins that really benefit from storage are the 7CT1N and the 7L12/7L13, but it makes more sense to get a 7613 to use with them.)

The 7844 is OK, but don't expect to get much out of the dual beamness.  (I usually just put the readout on one of the beams, so it doesn't make the trace flicker.)  Do not buy a 7844 with the P11 (eyehurt blue) CRT.

Try to get 7A29s instead of 7A19s or 7A24s... instead of unobtainium fuses, they have resettable input protection.

7B80 and 7B85 form a set.  Also consider the amazing 7B92A.

Instead of a 7A11, look for a P6201 or P6202.

The 7L spectrum analyzers are really, really hard to repair and maintain.

Thanks for the advice. Yes there was supposed to be a "|" between the 80 and 85; editing error on my part.  I've read about the SA issues on the tekscope list but it is such a cool plug-in.   

You could just buy two individual 7000's (any excuse  )

Edit: actually when I bought that 7603 about 18 months ago the dude was trying desperately to sell me the storage one he had too. I waltzed straight past that

I have a 7834 frame. Someone gave it to me somewhere along the way but I don't remember the details (a sure sign that I have too much stuff).  I just pulled it off the shelf and powered it up just to see if it works. It does, though the display isn't nearly as bright as I'd like it to be and unit is, overall, in pretty rough shape.   

I know I want a 400MHz frame. I don't know that I need either storage or dual beams. Of the two, dual beam sounds more useful. Maybe I should just go for the 7904?   

[WastelandTek]

So, I am fully aware that this is very weak sauce for this thread, but I am pretty happy and feel that I have my time thing sorted for the time being.

A rubidium standard will always be waiting for me when I can afford it some day...

[edavid]

I know I want a 400MHz frame. I don't know that I need either storage or dual beams. Of the two, dual beam sounds more useful. Maybe I should just go for the 7904?   

If you found a good 7854, 7904, or 7904A, I don't think you would miss the dual beam feature much.

(Unless you have OCD about readout-induced trace flicker, as I mentioned.)

[0culus]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

[worsthorse]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

muahahahahahaha!  at this point, my problem is definitely not not enough oscilloscopes...

[Neomys Sapiens]

I wanted to respond about the 7xxx question, but truthfully: no, I don't want one.
Because of space at home and portability elsewhere.
Maybe I am under shock - having narrowly escaped another unspeakable service action involving rotary aviation and freezing temperatures. Luckily I scrutinized the pictures close enough to see the coaxial overvoltage arrester where it does not belong. Well yes, this fault can be level-dependant. I am curious whether the power amplifier survived unscathed, which will be seen when the offending item has been removed.
Did I mention that I am supposed to be in R&D?

[med6753]

My money is on this:  you'll end up replacing the filter caps on the new-to-you 485, it'll require minimal repairs, and you'll end up hunting for another parts mule 485 because you wont want to sacrifice the working one for the other one. Only time will tell, though....   

I have two 485's and a dedicated parts unit (no case, already tried to get it running and think the CRT is toast, anyway...), but I lack the time as I have to finish remodeling the current project house in 70 days and it's a solo mission...  I've got a 12' long shelving unit that is literally filled with Tek goodies to restore once I have some time... Oh, and a kitten that loves climbing all over it 

Been down that road before with some 465B's. Had 2, one was not working. Bought a supposed non-working 465B for parts. It turned out to be in better shape than the one I had for repair. So mine became the third unit for parts.

We'll see tomorrow when I open up this 485 at poke around.

[0culus]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

muahahahahahaha!  at this point, my problem is definitely not not enough oscilloscopes...

Fixed that for you. 




 

[med6753]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

muahahahahahaha!  at this point, my problem is definitely not not enough oscilloscopes...

Haven't yet really found a need for dual beam and I definitely want nothing to do with old storage scopes. Sometimes lady luck falls into your lap and it's a easy decision. 7904 with 500MHz goodness and 4 plug-ins for $100 who could say no? Yea, the power supply was in tick mode but the fix wasn't bad.

[Mr. Scram]

So, I am fully aware that this is very weak sauce for this thread, but I am pretty happy and feel that I have my time thing sorted for the time being.

A rubidium standard will always be waiting for me when I can afford it some day...

All test gear is welcome. The TEAurch doesn't judge. The Pile welcomes all.

[med6753]

All test gear is welcome. The TEAurch doesn't judge. The Pile welcomes all.

That is unless you want to calibrate your DMM's via unconventional means but with a logical and sound methodology. Before the ink is dry the naysayers and finger pointers are all over you like flies on a dung heap.     

[WastelandTek]

Praise be to The Pile

amen

[mnementh]

Just a random thought off the top of my head...  is the deal with people being so anal about the absolute temperature accuracy of their soldering stuff...?

Even if the tip/air temp is dead-on, you STILL have to pay attention to how the work is going and be prepared to adjust as much as +/- 10° or more... there are just too many variables in how any individual part heats up to be able to set a fixed temp for all work. Yes, you should still be starting out at ~600°F for leaded and ~700°F for unleaded, but seriously... once you get past the "absolute noob" skill level you should be knowledgeable enough and confident enough in that knowledge to fine-tine for any situation on the fly.

I'm getting SMD parts off OK with the hot air system. I looked at a lot of tutorials on YT but I never got a definitive answer as to air temp and air flow to use for desoldering (wide array of "expert" answers). I've been using 380 C and "medium" air flow. Does anyone disagree with those settings? 

Sounds about right in the mid-high normal range for unleaded solder. 

You'll want to lower your flow for smaller stuff so parts don't blow away before you can grab them; but desoldering parts is how you get a feel for what's right. Up to a point, slower airflow will transmit heat better to a small area. When you need to heat larger masses (like a ground fill) and larger areas to remove a part is when you need to turn up the flow. Always modulate flow before you crank up the heat.

Carry on; before long, you'll be doing BGAs!!!

mnem
*ploop*

[mnementh]

All test gear is welcome. The TEAurch doesn't judge. The Pile welcomes all.

That is unless you want to calibrate your DMM's via unconventional means but with a logical and sound methodology. Before the ink is dry the naysayers and finger pointers are all over you like flies on a dung heap. 

It had nothing to do with that; it was all about haranguing papa smurf.

mnem
 

[mnementh]

Uh...mnem   flu like symptoms??    what continent you on??   

Racoon City again 

Well, it took him 5 days but my son is feeling better now. I just traded bedrooms and bedclothes with my daughter, so I could quarantine myself away from my wife in hopes of saving her from this evil.

Thanks everyone for your get-well wishes. I'll pop in from time to time as the drugs make it possible for me to see the screen and type. 

mnem

[worsthorse]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

muahahahahahaha!  at this point, my problem is definitely not not enough oscilloscopes...

Haven't yet really found a need for dual beam and I definitely want nothing to do with old storage scopes. Sometimes lady luck falls into your lap and it's a easy decision. 7904 with 500MHz goodness and 4 plug-ins for $100 who could say no? Yea, the power supply was in tick mode but the fix wasn't bad.

yikes, i forgot about your 7904 find... did it come with the fast plug-ins, too?

[Martin.M]

Do not buy a 7844 with the P11 (eyehurt blue) CRT.

correct. Bring it directly to me. 

this is my 7844, opt 21 (dedicated slots) + opt.78 (P11, blue beams)


The only what is not so amazing is the readout system:
Some segments are "thin" displayed, by example:
a 8 looks like H. Also 6 and 9 the vertical bow is thin.
This may be better with a phosphor what have a longer delay then P11.
The little problem is not to see with simply vertical plugins bec. they use almost 1,5,0 , no 6,8,9
but counters, DMM read out results , so they do that.
P11 looks best with a sunglas filter (smoke grey, not blue), you see that here. The blue P11 was made for using the large Polaroid cameras, the films was very sensitive for the color.
A lot of digital cameras are also very sensitive for that, so the intensity must be low to get fine pictures.

[med6753]

Are you having a Discord meeting today at 1900 hours UTC? I haven't seen any recent mention of this. 

[med6753]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.


_{and you should have more than one oscilloscope anyway!}

muahahahahahaha!  at this point, my problem is definitely not not enough oscilloscopes...

Haven't yet really found a need for dual beam and I definitely want nothing to do with old storage scopes. Sometimes lady luck falls into your lap and it's a easy decision. 7904 with 500MHz goodness and 4 plug-ins for $100 who could say no? Yea, the power supply was in tick mode but the fix wasn't bad.

yikes, i forgot about your 7904 find... did it come with the fast plug-ins, too?

It came with a 7A26, 7A24, and two 7B80's.

[Cubdriver]

Do not buy a 7844 with the P11 (eyehurt blue) CRT.

correct. Bring it directly to me. 

this is my 7844, opt 21 (dedicated slots) + opt.78 (P11, blue beams)
(Attachment Link)

The only what is not so amazing is the readout system:
Some segments are "thin" displayed, by example:
a 8 looks like H. Also 6 and 9 the vertical bow is thin.
This may be better with a phosphor what have a longer delay then P11.
The little problem is not to see with simply vertical plugins bec. they use almost 1,5,0 , no 6,8,9
but counters, DMM read out results , so they do that.
P11 looks best with a sunglas filter (smoke grey, not blue), you see that here. The blue P11 was made for using the large Polaroid cameras, the films was very sensitive for the color.
A lot of digital cameras are also very sensitive for that, so the intensity must be low to get fine pictures.

Right?  I've been looking for a P11 scope for a while now, but haven't seen any that were reasonably priced (and have seen damned few of them period).

-Pat

[Dek]

Praise be to The Pile

amen

Teallelujah brother.

[AVGresponding]

A Tek mainframe scope would be way more than I'm ever likely to need; my fully loaded TDS420A is plenty good enough, and if I need a component tester I have the Hameg 302-6, and if I ever get around to repairing the concave front panel, a PM3218.

I suppose there are plug-ins I'd find useful, but I've no idea what's available beyond the obvious stuff. An SA is the only thing I'm missing, but it's a low priority item for me, as I've no large interest in RF stuff beyond maybe snooping on my RC transmitter.

[tggzzz]

Dual beam does have one huge use case: looking at two signals of widely different frequency. Unless you do this a lot, it's probably not needed other from the cool factor.

Dual-beam storage scopes have another.

Consider capturing two channels of a single-shot event where the event duration is so fast that a CHOP sweep cannot be used. Good luck trying an ALT sweep