Roy,
I got very lucky a couple weeks ago and scored a basically pristine 7104 and it's intended plugin complement at a .gov surplus auction for a very good price (all of the above for $125). It is obviously well cared for, as the crt is crisp, bright, with the only signs of any problems being around the readouts, which are a bit dim compared to the traces (which isn't unexpected I suppose). I've found it is very easy to get a perfectly usable trace for all but the fastest signals at very low brightness levels...low enough that the limited view circuit either isn't kicking in or it's in the 20 minute timeout region (beam current above 0.2 microamps, but less 2 microamps) than rather than 2 minutes (2 microamps or above).
It's truly a tour de force for Tektronix analog scope engineering; beautifully crafted inside and out, with incredible performance.
Sean
toggle quoted message
Show quoted text
On Wed, Aug 21, 2019 at 06:55 AM, Roy Thistle wrote:
Hi Dennis:
We have 2 7104s... and occasionally I see one for sale, and the picture of it
usually shows it operating with the amber "limited viewing time" indicator
illuminated.
I'd only pay the prices most are asking for a 7104, if I thought I could get a
good spare MCP CRT, with some good life left in it. A cheap 7104 might be
worth it, just for the parts though.
I take it by your post... that even though the janitor tripped over a 7104 in
the hallway, outside the research lab, and is now selling it... the CRT should
be good, even though it may have operated in "limited viewing time" mode
frequently?
Best regards and wishes.
Roy
