WhitakerAudio
 
Gallery of Heathkit Restoration Projects

Photos are shown below of additional Heathkit test instrument restoration projects using the techniques detailed on the IM 5248 project page. The end goal of this work is to refurbish nearly all test equipment on my bench to the style developed for the IM 5248. This work is time-consuming, and expensive. However, the end results are very nice. So, I will keep going...

 

IM 5258 Harmonic Distortion Analyzer

The original front panel for this instrument is shown on the right, with the polycarbonate overlay next to it. As with the IM 5248 project, the original front panel was scanned and reproduced in Adobe Illustrator. The finished instrument is shown below. The case panels were done in a powder coat finish.

Nearly all of the front panels done so far (and documented on this page) were first versions. In a couple of instances, however, a second panel run was required to get it right.

Original front panel Polycarbonate overlay front panel for IM 5258
Front view of IM 5258 Side view of IM 5258

 

IO 4510 Dual Trace Oscilloscope

The original front panel of the instrument is shown on the right, with the polycarbonate overlay next to it. The front panel for this instrument is somewhat complex, but manageable.

The finished results are shown below. It is quite a transformation. The photo on the right shows the instrument on a roll-around stand. As with the other restorations, the case was given a powder coat finish.

I have come to prefer the look of the all-white front panel over the two-tone (white and blue) of the original instrument.

The original front panel color and legends were contained on a plastic insert. As such, use of the polycarbonate overlay made for a clean, uncomplicated installation.

Origional front panel Polycarbonate overlay for IO 4510
Front panel of IO 4510 Side view of IO 4510

 

IG 5218 Audio Frequency Generator

The techniques used in previous update projects were repeated here. The original front panel is shown on the left, along with the replacement polycarbonate overlay on the right.

The finished results are shown below. A powder coat finish was used, as before. Most of the knobs were replaced with new units.

User preference comes into play when the look of an instrument is under consideration. My preference is the clean white panel with the nice contrast of the blue cabinet.

Front panel of original IM 5218 IG 5218 polycarbonate overlay
Completed IG-5218 Side view of IG-5218

 

IM 25 Volt-Ohm-Milliampere Meter

The IM 25 is an instrument from the "brown" era of Heathkit test equipment. In order to match the look of the other refurbished instruments, the overlay base color selected was white. The original panel is shown on the left, and the overlay is shown on the right.

The unit features a large meter and intuitive layout. The transformation was dramatic.

This instrument is a pleasure to use. The large, easy to read meter is a welcome break from LCD displays, which typically do a poor job of representing varying voltages.

Original IM 25 front panel Overlay for IM 25
Refurbished IM 25 VOM Side view of IM 25 VOM

 

IM 5238 AC Voltmeter

The IM 5238 is a popular, high performance ac voltmeter. The original front panel, shown on the left, had a white base with blue accent. The replacement overlay, on the right, simplifies the layout by eliminating the blue accent. This is another case where the blue accent on the front panel was eliminated.

With a number of different Heathkit instruments converted to the white base polycarbonate overlay, I have come to strongly prefer the consistent look of the white panel.

Owing to the construction of the overlay, aggressive cleaning is possible without risk of damaging the printed legends.

Original IM 5238 front panel IM 5248 overlay
IM 5238 completed instrument Side view of IM 5238

 

IG 1275 Sweep Generator

The IG 1272 is a perfect candidate for replacement of the front panel with a polycarbonate overlay. This instrument, like the IO 5410 (above) used a plastic insert over a metal base panel. Over the years, the insert tends to yellow. As shown in the photos on the right, the original panel was in bad shape. The replacement was an enormous improvement

The original panel insert did not have an adhesive backing (or at least it disintegrated over the years). This caused the old insert to fit poorly in some cases. The new panel solved this problem.

Original IG 1275 front panel Replacement IG 1275 overlay
Reconditioned IG 1275 Side view of IG 1275

 

IP 27 Power Supply

The IP 27 power supply is a popular instrument from the early 1970s. The basic color scheme is a beige panel and brown cabinet with black trim. Following the approach taken in the other instrument refurbishment projects, a white panel was produced with black and red lettering. The cabinet was refinished in blue to match the other instruments in this line.

The new front panel and cabinet color completely remakes the look of the unit so it matches the "blue line" of instruments.

Original front panel of the IP-27 Polycarbonate overlay
IP-27 overall view Front panel of IP-27

 

IM 4110 Frequency Counter

The obvious approach for the IM 4110 is to duplicate the look of the existing front panel to the extent practical. This was the starting point for development of the overlay. The original panel, with its translucent upper half, is quite difficult to duplicate with the available tools and processes. The compromise made for this overlay involves providing a window for the LED displays, rather than having the entire upper portion of the panel open. As in the original, the basic panel color is white, with black lettering and spot color (red and blue) for the legends as required.

Original IM-4110 front panel Replacement panel for IM-4110
Completed IM-4110 Finished instrument

 

IG 37 FM Stereo Generator

The IG 37 FM stereo generator is another product from the "brown era" of Heathkit test equipment. A later version, the IG 5237, is essentially identical, except for the color scheme, which features a white front panel and blue case.

Two screw-on "Amphenol"connectors are used on the front panel of the IG 37. During the upgrade, these were changed to the more common BNC type, which is also used on the IG 5237.

IG 37 front panel Polycarbonate overlay
Completed front panel Side view of IG-37

 

IP 2717A High Voltage Power Supply

The IP 2717A is a popular variable high voltage power supply for experimenters and schools. Two variable outputs are provided (B+ and C-) in addition to filament voltages. A large number of these instruments are in circulation.

The remake of the IP 2717A was straightforward. No modifications of the unit were needed. The front panel remake was complicated in that there's a lot of stuff on the panel. When combined with a new finish for the case and new Davies knobs to match the other refurbishment projects, this turned out very nice.

Original front panel of instrument IP-2717 overlay
Completed IP-2717 front panel Side view of IP-2717

 

IP 5220 Variable Isolation AC Power Supply

This project was a challenge. The first step was to remove all components from the front panel so it could be scanned to create the polycarbonate overlay artwork. Because of the construction of the unit, however, a conventional scanner was not used. The chassis and front panel are one piece of sheet metal, Problems relating to scanning included the size and weight of the piece.

Rather than use a scanner to capture the front panel, a photograph was taken and then imported into Adobe Illustrator where the artwork was created.

The end result was quite good, as shown in the photos.

Original IP 5220 front panel Polycarbonate overlay
Completed IP 5220 front panel Cabinet view of IP 5220

 

Audio Load Test Set

This project involved updating the front panel of a special-purpose audio load test set. The instrument carries no Heathkit model number, and I can't find it in old catalogs. It appears the unit was intended for service centers, rather than consumers.

In any event, the two channel load permits easy switching of the output of an amplifier under test between external speakers and an internal load. In addition, a switchable test port is provided.

Original front panel New front panel
Audio load exterior Audio load

 

Projects Completed

With the completion of the audio load test set (above), all of the equipment on the bench has been refurbished. The bench is shown in the photo below.

The test instruments are loosely grouped as follows (from top row to bottom row): RF, power supplies, signal generators, signal analysis, and test sets. In addition to the instruments shown, there are also two IO-4510 oscilloscopes.

It can be seen that there are duplicates for most instruments. This was done by design to allow for simultaneous 2-channel measurements. Also, in recognition of the age of the Heathkit equipment, having a second known-good instrument is probably a good thing.

I had previously collected many more Heathkit instruments, but sold them off over time as it became clear what instruments I would use, and those that I would likely not use. The projects that I expected to do in the future drove those decisions. I have narrowed my focus to audio amplifiers and radio receivers.

Power for all the instruments comes from a single master switch to allow for convenient shutdown of all equipment. One copy of each Heathkit assembly/user manual has been collected for the workbench instruments.

In addition to the instruments shown here, a computer has been dedicated to measurement applications, as described in the About the Workbench page

Completed workbench