Tektronix 514: restoration update

A bag of parts from Newark arrived and I went to work replacing capacitors in the power supply.  First, I finished re-stuffing one of the cans:
IMG_5582.JPG IMG_5585.JPG IMG_5583.JPG IMG_5584.JPG

I’m really happy with how these came out.

Than went to work replacing the old bumblebee caps – here’s a few shots before I soldered and clipped the leads.  C102 is the re-stuffed can freshly installed.



I was conflicted about just ripping out old components and replacing them with new ones, but (and I’m paraphrasing his words from a conversation I had with Kurt): Tektronix used the best components they had available to them at the time.  If they had these newer, more reliable components, they would have used them instead.  You shouldn’t feel bad as long as the restoration is done in the spirit of the original design and keeps up with their level of craftsmanship.  I’m happy with my work so far and think I’m on the right track.

I decided to power this up on the variac.  It was almost midnight, so I didn’t bother with photos or videos, but:

I started to hear the whine of the high voltage power supply around 60 VAC on the input (frequency is around 4kHZ, wonder if this is right?).  Eventually I saw a fuzzy green dot on the screen around 80VAC, that quickly drifted off.  If I turn the intensity control all the way up, I see the familiar glow of on the screen you get when the beam is deflected way off the face.  All other controls are unresponsive.

The +1,500V supply is around 1,000V, the -1,500V supply is around -800V.  I would like to get those missing 1,200V back…  The -140V supply seems to regulate albeit somewhat loosely.  The 225V, not so much, and the 225V adjust control doesn’t do anything.  I’m suspecting I have to replace the reminder of the .01μF bumblebee caps in the supply.  Maybe I should just rename this hobby “replacing old capacitors”.

It’s a start!