Skip to main content

Heathkit TC-1 Tube Tester Restoration Part 1

 

Heathkit TC-1 Tube Tester Restoration Part 1

Filed in Heathkit TC-1 on Nov.09, 2018

Part 1 – Initial Inspection

I picked up this Heathkit TC-1 tube tester at the Williams, AZ Hamfest several years ago.  It had the power cord cut off at the entry, and a $10 price tag.  I took a chance that the transformer might be good, and picked it up.  Now to find out if it was worth the risk…

 
Heathkit TC-1 as found

The front panel was in pretty good shape, with a few knobs missing.  All controls moved smoothly through their positions.  The power cord is missing, and there is a little bit of corrosion around the mounting hardware for the controls and the lamp test socket.

 
Heathkit TC-1 bottom view

The bottom of the panel shows some light, powdery corrosion.  Mounting hardware for the tube sockets shows heavier corrosion.  There are bunches of bad solder joints to be cleaned up.

 
Set Line Rheostat

The “Line Set” Rheostat looks to be in good shape.  It will probably just need the connections touched up. The taped wire looks suspicious.  I’ll have to look into that

 
Selector Bank

Some corrosion on the bus wires for the selection switch bank will need to be cleaned up.  All of the switches have a dark oxidation on them to clean up.

 
Type Switch

That looks like a broken/burned resistor on the “Type” selector switch, along with one of the old style resistors on the right that typically are out of spec.  There is also some solder work to be done here.

 
Plate Setting

The large resistor to the right of the “Plate” potentiometer is just floating on one leg.  It would be nice to make that more secure.

 
Test Switch

The top left of the chassis has lots of corrosion on the tube socket mounting hardware, as well as plenty of bad solder joints to fix.

 
Meter

The meter appears to be in good condition, at this point.  We will probably need to change the capacitor on the back of the meter.

 
Tube Sockets

 

The right hand tube sockets are more of the same.  Corrosion on the mounting hardware and poor solder joints.

 
Data Roll

The paper data roll is in good condition.  I’m afraid to do much with it at this point, for fear of tearing it.  We will see how it holds up.

 
Cabinet

The cabinet has a large wax/oil spot on the side that would be above nothing that would cause that.  The transformer is on the other side of the cabinet.  I wonder if someone had the case on upside down for a period of time?  But I also do not see any leakage problem with the transformer, so this is a mystery, for now.

So, the plan:

1. Add line cord and check the transformer for proper operation.  If this is bad, the rest of the project would not be worth the time involved.

2. Remove all hardware possible, while keeping most of it tied together with the wiring.  Hopefully, I will be able to remove the front panel for cleaning the corrosion off the back, clean up the mounting hardware and reassemble.  I’m afraid I may have to unsolder all of the tube sockets to do that, though.

3. Disassemble the selector switches for cleaning

4. Reassemble components on to panel, attaching wiring.

5. Clean up all solder joints.

6. Clean potentiometers, remaining switches and rheostat.

7. Replace capacitor.

8. Test basic operation, and calibrate.

9. Potentially make mod to account for higher line voltage.

10. Add fuse to line cord.

11. Refinish cabinet.

12. Assemble into cabinet.

13. Find or make replacements for missing knobs.

Sounds like a project! Stay tuned for updates…

 

Comments

Post a Comment

Popular posts from this blog

Building the W8NX Short Trap Dipole

Image
  Building the W8NX Short Trap Dipole Filed in Antennas on May.31, 2021 For the past five years, I have been operating the lower bands (30, 40 and 80 meters) with a trap dipole that was modeled after a web article written by John DeGood NU3E. [1] While the antenna performed well, a monsoon storm last summer beat it up enough that the antenna wire broke at the center balun. So I climbed the tower and lowered the remains of the antenna to the ground for repairs. On closer examination, I discovered that the relentless Arizona sun had taken its toll on the traps. The insulation on the exposed ends of the coax had rotted away. They were still working, but would need to be rebuilt and weatherized to insure good operation many years into the future. Since I was going to have to rebuild the antenna, I started thinking about whether this antenna met my current needs and wishes. I had been wanting to get on 160 meters at this QTH for some time, but my small back yard w...
Read more

Yaesu G-450XL Rotator Repair

Image
  Yaesu G-450XL Rotator Repair Filed in Antennas on Dec.30, 2007 In December of 2007, the rope support for the center element of my Cushcraft A3 broke, requiring me to climb the tower and bring the beam down for maintenance.  At the same time, at had been noticing that the rotator control was not indicating correctly, it was very erratic.  So I brought the rotator down for maintenance, as well. The first step was to mark the side of the case, where the top and bottom of the clam shells connected together.  This would allow me to assemble it in the correct alignment when the time came.   Marked Case of Rotator Next, I took the top cover off.  All of the bearings between the clam shells in the depression on the outside were safely stored.   Top Removed A little inspection revealed what the problem was.  The center gear had broken away from the shaft it was pressed onto.  I tried re-pressing it back onto the shaft, but it was to...
Read more

Kenwood TS-790A Light Replacement

Image
 I noticed a while back that my TS-790 meter displays had gone dim.  While I had the radio opened up to adjust the master clock. I decided to replace the burnt out incandescent lights with new white led lights. I neglected to take any pictures until after the work was done, but this will show where the lights are located, and which led bulbs I used to replace them. To access the 3 bulbs for replacement, I removed the top cover.  This and the bottom cover had already been removed in a prior repair in my case.  So I don't know if the bottom cover needs to come off or not. There are two screws on each side of the front faceplate.  I removed the top screw and loosened the bottom screw to allow the faceplate to tilt forward off the edge of the bench.   Faceplate Screws   Be careful when tipping the faceplate forward.  I managed to break one wire out of a connector on the bottom right side.  I was able to reattach the wire with the faceplate open....
Read more