What a great job you did, timb
I was surprised by how out of shape your unit was and how you've brought it back to life, and looking forward to seeing your upgrades.
I'd be curious to see whether the panel meters will inject a tiny bit of noise into the output if you build it into the chassis.
I'm like MarkPalmer on maintaining the original look and technology as much as possible, and when I do need better metering of the power output, just drop my eload in series or use separate DMMs.
I've kept original labels from the primary owner whenever possible [ not the seller]. The top one was from Boeing, and one of the others is either Martin Marietta, or Grumman but fell off, and one from a cal lab that has stickers on the screws not to open it . Aside from cleaning and some Dexoit, the units are working as they came OOB from eBay.
Agreed! very nice job
Thanks guys! Yeah, I worked hard on this one and I appreciate all the help from everyone here. Physically, I would have *liked* to keep this 2020B stock, but the panel meter was broken beyond repair and I haven’t been able to locate a suitable replacement edgewise meter, so I figure doing some sort of retro looking digital meter would be my best bet.
That’s why I was thinking of using the HP bubble displays, to keep it from the same era:
As for noise, I doubt it will inject any noise. I can always use an Op-Amp on the input of the panel meter chip so I don’t place any load on the output itself (though I imagine that’s already part of the chip). I can also use one of those cheap 5V supply isolators to power the chip if I do see any noise. I highly doubt that will be an issue though.
I also did consider rebuilding the old meter with a Switec X27.168 servo, which could have been cool.
The other option is using tiny individual LEDs on a board to make a custom bar graph type deal. I’d custom print markings on translucent vinyl and place it in-front of the LEDs and behind a clear piece of acrylic glass in the meter cutout.
Not sure what would look the best, though I’m going with the LEDs.