Amptech Systems & TUBETVSHOP.COM

&

Sylvania 21LC28

Home Our Services About Us Tube Audio Sets for Sale Parts & Accessories Restoration Shop Special Cases Cabinetry Service Sample Restorations Packaging Request Restoration FAQ Links In Loving Memory

 

I've owned this set for over twelve years.  When I first moved into my new home, I put this set in temporary storage.  Here is the set when I first brought it out of storage.  The swivel base was temporarily removed for transporting the set.  Inside and out, the set is thoroughly inspected.

Although the original components still function, I have opted for precautionary replacement of the "voltage-doubler" capacitors in the low-voltage power supply.  The new capacitors are mounted under the chassis.  The remainder of the restoration consists of making the final "setup" adjustments.

The new capacitors help to restore full B+ supply voltage, which was only about 10% lower than the value specified in the service literature, brightening up the picture noticeably.  I also performed preliminary grayscale setup.
The base is now reattached to the set's cabinet.  Proper adjustment of the HV Regulator helps to further improve picture quality.
Convergence and final grayscale tracking adjustments are next.  Overall, static and dynamic convergence results are excellent for this type of set.
Overall performance is checked using several test patterns.  In this photo, a "gated rainbow" pattern is displayed.  Although not shown in the photo, a  Vectorscope is connected to the set during this test to evaluate the performance of the chroma processing circuitry. 

 
 
Send mail to webmaster@amptechsystems.com with questions or comments about this web site.
Last modified: 07/29/16