Rob is a braver ham than I. When my Tek 465 quit, I tried to fix it, but quickly chickened out.
Very nice that he painted his in Juliano Blue.
Dear Bill and Pete,
I do enjoy your podcast, and I must present an offering to the "Gods of Homebrew",
An on-line find of an old Tek 545 oscilloscope presented a chance to enjoy the warmth of 100+ tubes (once repaired)
The outside was heavily scratched, the inside looked like a chicken coup, but no major bits missing or broken.
Lots of cleaning, testing all tubes,(using the excellent uTracer tube tracer), replacing the broken 3, remounting the cooling fan, lots of reading about tube oscilloscopes, adjusting the trigger circuit, rebuilding 3 electrolytic power supply capacitors, sandblasting the cabinet and a coat of BLUE paint.
Voila, the joy of (visual) oscillation! (1MHz 2V p-p)
Rob VK5RC
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My 545 developed ripple in the trace soon after I got it (someone I knew saved it from being tossed, complete with plugins and manual).
ReplyDeleteI took off the cover and probed the "lower" voltages with the probe, until I found a point where touching it increased the ripple on the trace.
Most of the electrolytics in the power supply were fairly large values (for the tube era, but I was surprised the local surplus outlet had the right value. And putting it in got rid of the ripple on the trace.
Michael
Oh, man, I love those things. There were still a few floating around in the early 70s in my college days. They were the sort of stuff that pulled me into an EE career.
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