One in a series of occasional articles to share best practices for DIY projects.
My gold mine is the Kutztown Radio Show in Kutztown, Pa. I am drawn consistently to one table where the vendor has a plethora of clock radios. He disposes of a friend’s collection, and buyers benefit from radios that were part of of it. Most of them have had no work done at all and are pretty much as they left the factory, except they’re 60 years old.
This case involves a 1965 Zenith N514G radio.
Zenith, as the name implies, is the peak or the top. That has always been my feeling with radios and TVs: Zenith are the best.
When I had it on my workbench, I found that the radio had the usual flaws that occur over the years.
The painted silver trim around the edge was coming off. The plastic covering the clock face was cracked. The knobs were yellowed and dirty. And the radio had a lot of scuffs and dirt marks.
It was complete and the AC cable in the back was in very good shape.
The first step, always, is to check everything inside before you plug it in to make sure there are no potential problems.
This radio had no screws attaching the circuit board to the bottom. Instead, it had a fiber board back that I had to pry apart gently with a screwdriver.
The speaker was no longer attached to the plastic housing in the front, because the indentation plastic support pieces where it lived had broken off and were still attached to the screws. Two of the female ports for attaching the speaker were in good shape but another two had broken off.
The combo electrolytic capacitor was on the bottom of the chassis and there are a couple of nuts that had to be removed to slide the circuit board out.
Note how Zenith packed every component into such a tight space.
Now it was time to remove the circuit and test the tubes, resistors and capacitors.
One of my biggest complaints with vintage radios of the era is that once the circuit board is removed, you have a very short leash to work on anything.
The two AC wires that attached to the male receptacle were too short; they didn’t give me enough room to slide the board out completely. A third wire traveled from the clock and was soldered to the circuit board and that was also too short.
Luckily, the two additional wires connecting to the speaker were long enough so that the circuit board could travel out unencumbered.
I was limited by three wires. Apparently, manufacturers didn’t want you working on these innards.
So instead of having the wires rip and forgetting where they’d been attached, I used black, white and blue wires and extended each one about 10 inches so I could comfortably take the circuit board out and work on it.
I don’t normally like to extend the wires of a vintage radio, but too many times I’ve twisted and angled a circuit board too much and the wires became unattached from the board. Trying to save one step complicates everything else and too much time spent trying to determine where the wire was connected.
The purists may say this wasn’t how the radio was designed, using extended wires. True, but this probably was a cost-saving measure, and these radios weren’t meant to be serviced by the user.
I want the radio to function properly and be a safe and nostalgic gift to the recipient. That said, my wire extensions needed to be safe: connected properly, soldered and with heat shrink tubing covering the joints.
I did notice that several of the other mounting screw locations had broken off. These could all be super-glued back on. At least now I had access to the board.
My method is to replace all the capacitors first and then check the voltage of the resistors. This radio didn’t have wax capacitors (always replace those), just mica caps and an electrolytic. The mica caps rarely need replacement as they tend to hold their values, but I still check them.
I decided to leave the old electrolytic combo capacitor in place but cut the wires and attach new electrolytic capacitors to the correct wires. They shared a common negative, but the original 40 microfarad (mf) was replaced with the 47 mf and the 80 mf was replaced with an 8 2mf.
I used a digital voltmeter to test the value of the resistors. All of them, at age 60, were within tolerance.
With the circuit board still removed, I had the opportunity to remove dust that had collected in the bottom of the shell.
Normally, I use a vacuum and a small brush, but the dust wasn’t too deep so I just used some window cleaner and paper towels to remove it from the crevices.
If the clock motor weren’t functioning, this would be the time to remove it and lubricate it. But the clock was still running, so I just cleaned up the oil that had spilled out over the decades.
Now I turned my attention to the exterior.
A lot of the silver paint had come off around the trim of the outside shell. The easiest and neatest way of correcting that was to mask off the area with blue painter’s tape and then carefully apply silver paint.
I prefer using a silver marking pen to avoid brush strokes, but in this case the marker didn’t adhere to the plastic. I removed the plastic bezel over the clock by prying it out gently. The scratch was too deep to remove. Replacement plastic is available from the Retro Radio Repair website for $22.
I removed the knobs and dropped in a solution of Dawn and water, and soaked for 24 hours.
I scrubbed and cleaned the plastic cabinet with Mr. Clean Magic Eraser. This alone makes a big improvement. Then I removed surface scratches by first using the more aggressive Novus Cleaner #3 with the green label, then #2 with the red label for the finer scratches. Meguiar’s Liquid Carnauba Wax completed the polishing process.
With the Zenith restored to like-new condition, I could add it to my collection to gather dust on the shelf with the rest of minions. Or I could give it as a gift so someone else could enjoy it. You’ll never guess which option my wife told me to select …
