Repeating issue, Birch/Grinnell portable

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paradroid1793
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Repeating issue, Birch/Grinnell portable

Post by paradroid1793 »

My portable I recently purchase is repeating on a record. I've adjusted the speed, oiled the tonearm, and replaced the needle.

Anyone have any idea what could be wrong?
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JerryVan
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Re: Repeating issue, Birch/Grinnell portable

Post by JerryVan »

Either the swivel at the back of the tone arm, or the joint in the tone arm is stiff and dragging. I kind of think it's the joint in the tone arm not allowing the reproducer to rise and fall with the turntable wobble. Notice if the needle is raising off of the record as the turntable rises and falls.

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paradroid1793
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Re: Repeating issue, Birch/Grinnell portable

Post by paradroid1793 »

Hmmm... I've brushed some oil around the areas of the arms movement to some little results. I'll keep trying.
Be sure to look up Samuel Murchison Seka on the interwebs for some music and phonograph reading material.

JerryVan
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Re: Repeating issue, Birch/Grinnell portable

Post by JerryVan »

paradroid1793 wrote: Fri Oct 17, 2025 8:15 pm Hmmm... I've brushed some oil around the areas of the arms movement to some little results. I'll keep trying.
If the problem is swollen pot metal parts, no amount of oil will really fix it.

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Re: Repeating issue, Birch/Grinnell portable

Post by Lah Ca »

Repeating and expanding upon JerryVan's advice ....

The arm should move quite freely back and forth. Unfortunately the base of the arm cannot easily be taken apart and reassembled on Birch machines. So turn the machine up a bit on its side and put a few drops of good quality machine oil into the joint at the base of the tone arm. The set the machine flat again. Sit and watch TV or something .... and keep working the arm back and forth gently and slowly across the full range of its movement. Do this mindlessly ad nauseam. You want to reach a point where there is little or no resistance to the movement of the arm.

The gooseneck elbow should also move up and down quite freely. It is made so that it binds a bit at the top of its vertical movement to help with changing needles, keeping the reproducer/sound box from crashing down onto a record. But other than that tightness at the top, it should move freely.

If the elbow does not move freely, it can be removed with care. Remove the reproducer. Put a drop of penetrating oil on the screw that holds the elbow in place. Wait. Remove the screw very gently. Do not force it. Now work on loosening and freeing the elbow. Oil and patient persistence may be required. Do not use much force. Pot metal is very fragile. Once the elbow is out, you can polish up its end and the socket it fits into on the tone arm using steel wool. Pot metal swells with age so you may need wear the old metal down a bit to get a looser fit. Work on it. Clean it. Do a test fit. Repeat as needed.

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