General Electric HM-171 Restoration

The Cabinet.  Click here for pictures. The cabinet is in excellent condition. All that is needed is some touchup. The touchup has been completed.

Though our set had an original escutcheon for the channel selector, two other collectors had GE sets that were missing theirs. After quite a bit of research, we were finally able to find a company that could make replicas. Here is the replica, along with the original plate:

The Chassis. Click for pictures or technical information. The chassis will be cleaned with water and a mild detergent using soft brushes to get into small places. Then, all paper capacitors will be replaced with modern ones (see the procedure for this). Each electrolytic capacitor will be tested for leakage and capacity. If bad, new electrolytics will be installed inside the old ones.

This chassis has been modified to add an audio output stage, using the HM-185 design. The 6H6 detector was replaced with a 6SQ7 detector/audio amplifier, and a 6V6 was added. A volume control was installed next to the brightness control and a hole drilled in the cabinet. In addition, the horizontal oscillator tube, originally a 6F8, was replaced with a 6SN7. We have returned to chassis to the original design.

After rebuilding all the paper capacitors, we found several bad resistors, including a 20 watt wirewound one in the power supply circuit. The set worked perfectly after replacing these parts and three bad tubes.