Hey gang. Got the R-1261 working with 'a little help from my friends'. After replacing the filter cap and a few others, has a strong selective signal response. Problem is, speaker distortion. The speaker is in fine looking condition, good cone and wiring. I removed the magnet to get at the dust.... no improvement. There is some sliding noise when moving the cone in/out. I tried to adjust by positionig the core magnet. Mute is the only change that is noticed. When the strongest sound is realized, there is a raspy tone along with volume increases. I would hate to replace it with a fixed mag type. Help?

Hi Pat, You're lucky that it's an electrodynamic speaker and can be pulled apart to service it, also you don't have to worry about magnetism when there's no power. Check the pole pieces to see if there's any rust or particles stuck to them. Make sure the voice coil is round (no bumps) and hasn't got any loose turns of wire. You can place the coil over the disassembled pole pieces to prove they clear. Check the centering spider isn't broken. Sometimes the cone can sag out of shape by gravity after many years. Sometimes this can be overcome by rotating the speaker 180 degrees so it sags back into shape. It could be distortion in the output stage, perhaps due to a leaky coupling capacitor , gassy tube, etc. but since you can hear the cone rubbing when you move it, fix that first. You can wire an external permag speaker in place of the original voice coil to check the receiver is undistorted.
Good Luck, Don Black.

: Hey gang. Got the R-1261 working with 'a little help from my friends'. After replacing the filter cap and a few others, has a strong selective signal response. Problem is, speaker distortion. The speaker is in fine looking condition, good cone and wiring. I removed the magnet to get at the dust.... no improvement. There is some sliding noise when moving the cone in/out. I tried to adjust by positionig the core magnet. Mute is the only change that is noticed. When the strongest sound is realized, there is a raspy tone along with volume increases. I would hate to replace it with a fixed mag type. Help?

Hi,
I have restored a couple of speakers that had a slight bind in the voice coil by two different methods. I would first try the shimming method I describe at the end of this first, then try the coil re-forming method that will work best for your situation.

1)I had a pair of speakers (permags) that had distorted voice coils, but the windings were still tight to the form, that I burnished the interfering area away from the magnet- in your case it would be the pole piece, but the principle is the same. The advantage is that the area of interference was the only area that I disturbed, I did not risk damaging the coil by exposing the weaker area. This does not always work, but is worth a try, especially if there is no dust cap in place.

2) I resorted to the tool box to find a socket of the correct diameter on the outside to use as a forming mandrel, and gently forced the socket through the voice coil's distorted area. This only works if the coil form has not kinked very badly.

Lastly, because there is some play in the pole piece mounting holes, upon re-assembly any time the unit is taken apart; if there is no dust cap, or if it is easily removed, cut a "shim" to encircle the pole piece without overlap. This centers the pole piece and voice coil combination. Use some grocery bag, or other paper that has a little thickness to it.

If these things do not resolve the problem, check to see that the coil form is not skewed tot he centerline of the pole piece ( or vice versa- depending on how the speaker was assembled).

: Hi Pat, You're lucky that it's an electrodynamic speaker and can be pulled apart to service it, also you don't have to worry about magnetism when there's no power. Check the pole pieces to see if there's any rust or particles stuck to them. Make sure the voice coil is round (no bumps) and hasn't got any loose turns of wire. You can place the coil over the disassembled pole pieces to prove they clear. Check the centering spider isn't broken. Sometimes the cone can sag out of shape by gravity after many years. Sometimes this can be overcome by rotating the speaker 180 degrees so it sags back into shape. It could be distortion in the output stage, perhaps due to a leaky coupling capacitor , gassy tube, etc. but since you can hear the cone rubbing when you move it, fix that first. You can wire an external permag speaker in place of the original voice coil to check the receiver is undistorted.
: Good Luck, Don Black.

: : Hey gang. Got the R-1261 working with 'a little help from my friends'. After replacing the filter cap and a few others, has a strong selective signal response. Problem is, speaker distortion. The speaker is in fine looking condition, good cone and wiring. I removed the magnet to get at the dust.... no improvement. There is some sliding noise when moving the cone in/out. I tried to adjust by positionig the core magnet. Mute is the only change that is noticed. When the strongest sound is realized, there is a raspy tone along with volume increases. I would hate to replace it with a fixed mag type. Help?