Well, the biggest problem right now is that while it's a really attractive unit, the resident 7000 would have to leave and it doesn't have permission, not yet anyway. Only room for one big unit on my work shelf.
In the meantime, I don't go through many tubes so can actually enjoy doing the curves manually with bench supply and graph paper. Doing it one step at a time also helps me take in what the tube is doing a little better .
This back and forth had me going for another look at the Tek website and thought it was cool to see they don't distance themselves from their old products - the now out of production for 30 years 7000 series scopes even having a FAQ page with suggestions for finding a used one to buy , get plugins for etc.
They're still proud of what they've done and suggesting buying it even though they won't make a cent. Pretty amazing.
Lots of info on old Tek products here at tekwiki:
https://w140.com/tekwiki/wiki/576
https://w140.com/tekwiki/wiki/570 (it's even heavier than the 576 )
https://w140.com/tekwiki/wiki/7904A
https://w140.com/tekwiki/wiki/7CT1N (only 1/2 Watt and still expensive: )
https://www.ebay.com/itm/235898013724
I don't believe the older Tek 561 series had a curve tracer plug-in like the 7000 series (was asked earlier ).
Here's an interesting one, I got one of these at a surplus store years back and it's still working well with a 7A29 plug-in and 7B92 with a 604 monitor as a storage scope, it was attached to a PDP11 with D/As and A/Ds, which I -should- have gotten too, I don't think anyone knew what it was: https://w140.com/tekwiki/wiki/R7912
A Tek 7403 is the main workhorse here.
I also have a Tek 7904A here. I especially liked how they made it "split-able" for easier servicing.
The 576 could have used something similar to make it easier to transport. 75 lbs
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That last 1 Amp curve trace of the QE08-200 above is showing some borderline instability in the LV low current Tetrode dips. Tetrode negative impedance kinks showing up with higher screen V.
Another instability sometimes shows up in B pentode tubes around the plate curve knees. The knees will be a little different depending on the direction the signal traverses the knee. 6JK6 is one such tube. The 576 provides a means to traverse the knees in either direction to check for that.
https://w140.com/tekwiki/wiki/576
https://w140.com/tekwiki/wiki/570 (it's even heavier than the 576 )
https://w140.com/tekwiki/wiki/7904A
https://w140.com/tekwiki/wiki/7CT1N (only 1/2 Watt and still expensive: )
https://www.ebay.com/itm/235898013724
I don't believe the older Tek 561 series had a curve tracer plug-in like the 7000 series (was asked earlier ).
Here's an interesting one, I got one of these at a surplus store years back and it's still working well with a 7A29 plug-in and 7B92 with a 604 monitor as a storage scope, it was attached to a PDP11 with D/As and A/Ds, which I -should- have gotten too, I don't think anyone knew what it was: https://w140.com/tekwiki/wiki/R7912
A Tek 7403 is the main workhorse here.
I also have a Tek 7904A here. I especially liked how they made it "split-able" for easier servicing.
The 576 could have used something similar to make it easier to transport. 75 lbs
---------------
That last 1 Amp curve trace of the QE08-200 above is showing some borderline instability in the LV low current Tetrode dips. Tetrode negative impedance kinks showing up with higher screen V.
Another instability sometimes shows up in B pentode tubes around the plate curve knees. The knees will be a little different depending on the direction the signal traverses the knee. 6JK6 is one such tube. The 576 provides a means to traverse the knees in either direction to check for that.
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