Monday, September 10, 2012


I am amateur radio operator WA5KSC.  Steve in Upstate South Carolina.  I enjoy both new and old ham radio equipment.  I decided to post some of my projects in hopes that my attempts would encourage other hams to enjoy both building new equipment and restoring old equipment.

Eico 460 Oscilloscope

I was fortunate enough to find a "new" 1972 Eico Wide Band Oscilloscope kit at the 2012 Dayton Hamvention from K4NYW.  Nick had quite a few kits that he had collected over the years.  Below are some pictures of the kit that I purchased that I grabbed from Nick's website.

I was a little worried that all of the parts were not there since the cartons were all open.  The chassis and cabinet had a few rust spots that needed attention as well.

I used naval jelly on the rust spots and over sprayed the cabinet.  Everything looked like new.  It also appeared that all of the parts were present.  Eico had placed protective film on the front panel as well as the plexiglass scale for the CRT.

The plastic film came off the front panel easily, but the paper backed film on the CRT scale took plenty of soap and soaking in warm water to remove.  

Here's a shot of the front panel with the CRT scale after populating some of the front panel controls.

My Eico 460 was one of the later versions of this oscilloscope.  The manual was pretty good, but not as good as those Heathkit produced!  There were a series of large charts that made parts placement easy.

I found that many of the carbon composition resistors had drifted out of tolerance.  I ended up replacing almost all of them with modern replacements.  One of the cement power resistors was also out-of-spec.  Based on feedback from my life long friend Barry, WA4VZQ, I added X1/Y1 by-pass capacitors to the line along with a grounded plug.  Barry also gave me suggestions on modifying the vertical input to accept a modern oscilloscope probe which I incorporated.

I suspect this one may have been faulty since manufacture.

I also substituted modern replacements for several paper capacitors.  Thankfully, the electrolytic can capacitor and HV capacitors were fine as were the Eico tubes.

Below are a few shots of the work-in-progress.  I have to admit to several boo-boo's that had to be corrected.  I was fortunate to have Sue, KJ4DLP, double-checking the work for errors.

The day finally arrived for first power up.  I used a variable transformed to slowly bring up the 460.  Low and behold I got a 60 cycle trace.

Apologies for the poor quality of the CRT picture.  I used available light without a tripod to take the picture.   However, I was excited the first power up didn't "let the smoke out!"

I have since aligned the scope and (almost) leveled the trace level with the grid.  I am pleased with the performance so far. 

Since I mainly work on boatanchors, the Eico 460 is adequate for me. 

I will post some additional traces as I work on projects.