Heathkit SA-2060 (non A version)

Several year ago I picked up a well-used Heathkit SA-2060 Transmatch. I used it for a while and then it was boxed up while I moved around or was using a different station configuration.

Known problems:
1) Inductor shaft slippage - shaft shows many signs of it occurring. (common occurance)
2) Internal ground connection from inductor to bushing broken due to nut coming loose on inductor.
3) Balun flashover to strap of C2 to the grounded winding of balun. (common occurance)

Solutions:
1) Shaft coupling would not hold on the damaged shaft so I made a new one out of brass and have two 6-32 set screws on each end. That allows for a much better bite on the damaged shaft. Loctite used on the set screws and no more problems.




2) At some point in this tuners life the nut which holds the bushing to the end of the inductor came loose and the shaft rotated, causing the damage. I notice it when the shaft coupling loosened up on me. At that time I pulled the inductor out to properly repair it and noticed the internal connection has been twisted off.

To remove the end of the inductor I tapped hard on the brass shaft with the handle of a screwdriver and managed to get the cap to move. Once it was loose it was a simple matter to it to gain access to the connection.
I removed the shaft from the cap and used a small butane torch to remove the old connection, clean it up and solder a new piece of braid from RG-58 to it. This would be impossible to do with a standard soldering iron.
The other end of the braid is slipped over the prepared end of the inductor and soldered into place. You must leave a bit of unsoldered braid so that the shaft can be located to the center to permit the inductor cap to be installed. Keep leads short.
Once the soldering it done, replace the end cap with a little glue to hold it in place. I used E6000 adhesive.


3) I have a roll of glass-cloth tape and will remove the damaged balun and rewind it to original specs. While it is out I will rewind the cores with clean tape to eliminate the carbon which was deposited after the arc and reinstall it. At that time I will address the proximity of the strap connection to C2.

This is the original balun after I removed it. I have never used the balun, but this failure was caused by RF arcing from the strap which runs between L1 and C2 to ground through the windings of the balun, which is grounded. This is a common problem due to the design of the SA-2060. I didn't notice the damage until I was checking out the inductor problem.
A view of the reworked balun. I protected the area of the balun near the strap to C2 by winding some additional glass-cloth tape over the windings. The dielectric strength of the Scotch (®) Glass-Cloth tape is around 3kv per layer. As additional dielectric strength, I used two wraps of 3mil thick Kapton tape over the offending strap as well. This adds an additional 9kv of protection to the balun from the strap. The Kapton is the golden stuff on the silver strap.
Back together and ready for service! You can see W2AWA marked this SA-2060 so I assume he was the original builder
Distance between the Balun and the C2 strap is only ~0.250"

 

After all this work to get the SA-2060 back in shape I opted to clean up the windings on the inductor which is showing its age.
Prior to cleaning. The inductor is in good shape for as old as it is. You can see the silver is worn and copper is showing through.
Above is my inductor after part of it was cleaned. I used a great product called Cool-Amp. Using a damp cloth, all you have to do is rub their silver plating poweder windings. The excess paste needs to be washed off. I used a brush to clean out the space between the windings and plenty of warm water. Excess water was removed with compressed air and then the windings were cleaned with alcohol and a lint free cloth.