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-----Original Message-----
From: David Berlind, Sent: Monday, May 14, 2018 12:02 PM

My main interest in a curve tracer would be for tube testing/matching. A
few months back, I believe there was discussion of a home-grown 576 fixture
for that. For now, one of my upcoming projects is to build my own tube
testing rig. For example, I'd wire up a single socket to some voltage and
amperage gauges and power the rig with an external DC supply across a
mixture of plate voltage and cathode resistance ranges. But that's a a lot
of work for each tube. I've seen a few hacks that convert old oscilloscopes
into curve tracers but haven't really studied any of them.

On Mon, May 14, 2018 at 2:43 PM, Kevin Oconnor <kjo@...> wrote:

Just chiming in...
I would agree with Chuck on this. Some other factors...
A 576 is way more complex inside with all the display lighting and

control.

If something fails, you have a lot more work to do. I just sold a 576
for
$750 and I think, for a fully working unit, it was a buyer bargain.
The owner just wanted it gone....

I use a 577 for just about anything discrete. I have a dozen fixtures.
(No IC testing though as mine has the 177 fixture) . Both are
versatile, and you can build fixtures to do things Tek didn't
anticipate or support. I'm working on a fixture to test Nuvistors.. A

work in progress though.

One caution (among many) If you get one and then go looking for
fixtures, be ware that many of the Tek plug-in fixtures have reached
EOL. The covers are screwed into bosses in the base boxes. Both the
threaded bosses and the covers themselves are now failing. As the
plastics aged they became brittle and the stresses have fractured the
bosses and the covers now pull away from the base. I have seen top
covers laced with hairline cracks causing the top to break up like a
jig-saw puzzle. So take a good look at what you are buying.

kjo

David Berlind wrote:
. . .
I saw this 577 Curve Tracer show up on eBay and it sold for $256. Not
sure if that power-up trace indicates an issue (not having had or
operated a curve tracer, I don't know what the power-up trace should look

like).

Following-on to conversations in this forum about the the 576, I've
been keeping my eyes out for a 576. Is there a significant difference
between the two?