• 2024
  • Dec
  • 13

The Heathkit IO-10 Oscilloscope - Part 1: Observations

In my quest to find a small bench scope, I picked up a couple of different models for a decent price. This IO-10 was a negotiated item - I mostly didn’t want to pay the asking price because it had a missing fuse holder cap, and that usually means that someone was working in the device trying to figure out why the fuse was blowing. Other than that, the device looked to be in pretty decent physical condition.

It arrived today in a box that, when new, was just a suggestion of cardboard and it didn’t really survive the trip. Uh oh. It was crushed somewhat and I expected the worst.

Opening revealed an apparently mostly intact device:

io101top.jpg

There was a lot of debris in the device. Paper, leaves, etc. I understand it had been sitting in a garage, but was it being used to shred leaves? Fortunately, all of the tubes are still in their sockets but you can tell they tried to vibrate loose. Most are the original Mullard, but there’s a couple of RCA, a Sylvania, and a GE device in here in the places you’d expect. Power supply, mostly. All covered with debris.

io101inside.jpg

io101power.jpg

Most of the controls and one of the terminals are just frozen with goo and damp corrosion. This is going to need a good dousing with alcohol and tuner lube. I can’t even turn the power control. It’s locked.

Unfortunately, because it wasn’t packed properly, it got damaged at some point, probably dropped on it’s corner. I am sad because this thing was otherwise in 8/10 shape. I’m going to ask a friend who does metalwork for some advice on knocking this dent out.

io101front.jpg

It doesn’t appear to have been touched except for tubes, and the one part seems to indicate this was made sometime around 1968. So, it’s not terribly old - the electrolytics may be still good (but unlikely due to garage storage.) Everything else is disc, so this shouldn’t need much more than some good filter capacitors and maybe a few of those carbon resistors replaced.

This one is going to need to wait a while before I get it on the bench, as the holidays and some work-related items are going to take priority. Check back soon for more on this device!

Next part of this series: Coming Soon.