(Fixing) “What Ails Your Old Phonograph?”

[Neophone]

What Ails Your Old Phonograph?

Now is the time to bring that portable wind-up phonograph down from the attic and put it in shape for summer. Rattles, shrills, wows, and the other awful sounds that phonographs may give out often come from easily correctable troubles. These photos show some of the common flaws and what to do about them.

Is the pickup head okay? If not, it will either bottleneck the sound or bring it out sour. A damaged diaphragm causes distortion and loss of volume. Small dents may be pressed out.

A needle holder that’s too loose causes rattles; one that’s tight reproduces records shrilly. Test the holder with your finger. It should have the tiniest amount of play. Don’t bother fixing bent or broken parts, for new heads are inexpensive. The new one needn’t be identical with the old one as long as it fits the arm.

Does the needle track? If it tends to jump the groove, inspect the side-to-side and up-and-down movement of the arm. It should be free in both directions. Polish arm joints with fine sandpaper. If the joint has a slot, make sure it is clean. Apply a dry lubricant such as graphite before reassembling the parts.

Does the table wobble? If so, it may bounce the needle out of its track and will probably put “wows” in the music. A piece of chalk tells the story. Hold the chalk firmly, rest your hand on a solid surface, and bring the chalk down till it just touches the felt. If the table is level, it should mark the rim evenly all around. Wobble may be caused by loose or missing mounting bolts or a bent spindle.

If you suspect that the bottom of the turntable is rubbing against the stop lever, speed regulator, or mounting board, chalk the lower edge of the rim liberally. The powder will rub off on obstructions or high points.

Is the speed right? Poor speed regulation can make records sound as if the musicians were being paid by the beat. Or it can turn a fox trot into a funeral march. Adjusting the speed-regulator arm should bring the speed to a fairly constant 78 r.p.m. This can be checked with a stroboscopic disk. Seen under an electric light, one row of lines seems to stand still when the speed is right. The disk shown at the left above has rows for all three phono speeds for both 50- and 60- cycle lights.

Another way to check turntable speed is to count revolutions, as shown at right. Slip a piece of paper under a record so that part of it projects. Start the motor and count the number of times the paper passes a point in a given time. Adjust the speed regulator until it counts 78 turns a minute.

Does the regulator regulate? If not, lift off the turntable and take a look at the linkage to the brake lever. Sometimes the collar that connects the regulator arm and lever comes loose. The collar bolt should be tightened. If the collar is tight, the governor itself may be faulty. You’ll have to check that next.

Is the governor sticking? The photo at right shows the parts of the speed-control mechanism. Three weighted balls or disks are spring-fastened to two collars on the shaft. One collar—which is attached to a brake disc—is free to slide on the shaft. As speed increases, the balls fly outward and pull the sliding disk against the brake shoe. The Three balls must be of equal weight and their springs of equal tension. If movement seems sluggish, the shaft should be polished and lightly oiled. Replace the brake shoe if it is worn or broken.

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Hopefully that was a bit easier to follow, and members and guests who are newer to the hobby (or to trying to service a machine) will be able to get something out of these directions that Larry so kindly provided.

Your friendly internet daemon,

MordEth

Folks, Here's the article LarryH graciously provided from the April 1950 issue of Popular Science Magazine. Originally posted in the Phonographs section.

Regards,
John

[MordEth]

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Note: please continue any discussion in the original thread.

— MordEth