My New RCA Victor Portable

[OrthoFan]

... It is simply not possible to tilt the front piece of the arm back to make the changing of needles easy. And if this were not so, the channel for the set screw is very short, so movement would be limited anyway....

The die-caste (pot metal) tonearms supplied by the third-party US manufactures during this period were not nearly as well designed or constructed as those made by the European (mostly Swiss) and British companies, which still seemed to take portable gramophones seriously. Nonetheless, you should be able to tilt it back to easily change needles, as seen here:

Capture.JPG (56.81 KiB) Viewed 757 times

I'm wondering if the front part (U-tube or sound box "crook") is original to that tonearm or a replacement.

OrthoFan

[Lah Ca]

Nonetheless, you should be able to tilt it back to easily change needles.
OrthoFan

Trusting in your wisdom and experience, I looked at it again. I took it apart again and reassembled it.

It still appeared that the U-Tube had very limited movement. Yet, the arm appears to be identical to the one in your pic above.

After measuring things and actually calculating what the range of travel the channel for the set screw should allow, I could see no reason why it should not be possible to tilt the arm up and back. Yet, it wasn't possible.

So ... if at first you don't succeed, get a bigger hammer. I used undue force on the arm, pot-metal-damage-risk force, And what do you know? It is possible. It's just not easy. But it does get easier, if not easy, every time I move it.

Screenshot from 2022-10-05 16-59-16.png (532.45 KiB) Viewed 739 times

I assume that the U-Tube should move freely and that it should be a pivot point that allows the arm to deal with un-even records and records of different thicknesses, much as the one on my new-to-me HMV 102 does.

So I am thinking that I need to be a bit more aggressive on my attack on the end of the U-Tube. Either that or mix some light abrasive with grease and just keep working it back and forth, cleaning, testing, and repeating until it is free.

[gunnarthefeisty]

Nonetheless, you should be able to tilt it back to easily change needles.
OrthoFan

Trusting in your wisdom and experience, I looked at it again. I took it apart again and reassembled it.

It still appeared that the U-Tube had very limited movement. Yet, the arm appears to be identical to the one in your pic above.

After measuring things and actually calculating what the range of travel the channel for the set screw should allow, I could see no reason why it should not be possible to tilt the arm up and back. Yet, it wasn't possible.

So ... if at first you don't succeed, get a bigger hammer. I used undue force on the arm, pot-metal-damage-risk force, And what do you know? It is possible. It's just not easy. But it does get easier, if not easy, every time I move it.

Screenshot from 2022-10-05 16-59-16.png


I assume that the U-Tube should move freely and that it should be a pivot point that allows the arm to deal with un-even records and records of different thicknesses, much as the one on my new-to-me HMV 102 does.

So I am thinking that I need to be a bit more aggressive on my attack on the end of the U-Tube. Either that or mix some light abrasive with grease and just keep working it back and forth, cleaning, testing, and repeating until it is free.

I would try sanding gently.

[Dischoard]

I went through the same thing with the pot metal elbow on a 40s RCA that I picked up except that mine was absolutely frozen solid. If you're careful just work a little toothpaste, lapping compound, something into that joint and gently work it back and forth until it starts to free up. I was finally able remove mine entirely and then sand it down, actually put it on a grinding wheel as mine had swollen so much. Works like butter now!

viewtopic.php?f=2&t=51527&hilit=rca

[Lah Ca]

@OrthoFan and Dischoard

Thank you for your help.

I worked more on the U-tube with files, sandpaper, and steelwool.

I have things working reasonably well now. I am not certain that I will ever get it all set completely well as the the end of the U-tube seems out of round.

However, I have enough free play in the arm now that I can raise the U-tube for changing needles. It is still a little stiff here but this OK; the arm cannot accidentally be knocked forward on to a record.

The big change is in the amount of free play in the other end of the U-tube's rotation. It is quite loose in the play and storage positions.

This looseness improves the performance of the machine greatly. I do not have to keep tweaking the needle rake angle to compensate for records with heavier drag or greater thicknesses. I can set the sound box/reproducer in place and leave it. The play in the arm now allows the release of tension against a record by allowing the needle to rise slightly as needed, I think.

It is now a totally different machine, much for the better. Major thanks.

[Lah Ca]

I finally got around to dealing with the needle cup that won't keep the needles inside.

The motivation here was that I have been taking the machine, with its record holder full, to various social occasions, much to the delight and amusement of all in attendance, and the leaky needle cup was very inconvenient. What is the point of having a portable gramophone if you don't port it?

I used a bit of gasket material from the same package that I used to redo the gasket between the U-arm and the reporducer. It stays in place without adhesive. Needles do not fall out.

The box of gasket material is proving to very useful for a wide variety of purposes, all of which, so far, are greatly removed from plumbing and facets.

[Inigo]

Nice and easy solution! I love to find modern available materials to repair machines. It ensures availability of spare parts!