Hi All, was thinking about replacing the EM speaker with a PM speaker in this little Freshman and noticed it is a bit different than a normal EM speaker. It has two wires going to the large coil and two coming out going to the speaker cone along with the two wires from the transformer that sets on top of the speaker. Is this some sort of a choke? There are 3 leads going to the cone of the speaker. Is there any way to replace the speaker. I wouldn't consider it but the cone is warpped and doesn't have very good sound. Thanks Again, George T.

Seems there is a tap on the field coil for grid bias (-7v)

When a cone is warped, you shim the voice coil (35 mm film works well for this) and then spray the cone with water. Once it has dried, it will have realigned. If it is stubborn, you might consider wetting the cone and also carefully wetting the spider with acetone.

No replacement is necessary. Replacement should be avoided whenever possible.

T.

:When a cone is warped, you shim the voice coil (35 mm film works well for this) and then spray the cone with water. Once it has dried, it will have realigned. If it is stubborn, you might consider wetting the cone and also carefully wetting the spider with acetone.
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:No replacement is necessary. Replacement should be avoided whenever possible.
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Hi, it is the paper that is warped but I think the water might help. I put a little toilet paper under the speaker frame on 2 sides and it helped alot. Will try the water and 35 mm film. That should take care of it. If not I will try the Acetone. I would definetly prefer not replacing the speaker. I guess I could send it off for a reconing also. Thank You All Again, George T.

Use the acetone on the spider only, and probably only if the spider is one of the more modern lacquered/varnished spiders, though you can try it on other types, too. If the spider is phenolic, nothing will happen to it if you soak it in acetone.

Use only water on the cone. If the cone is warped, then you definitely need to wet and re-set it. If the spider has set screws, you can also try re-centering the cone via the spider.

Also look for a broken spider. Early phenolic spiders have been known to crack, and other kinds come unglued.

DO NOT get acetone on the voice coil. Do not use acetone on the spider unless you absolutely cannot center the cone by other means. Be sure that if you do soften the spider with acetone, that the voice coil is properly centered in the pole pieces motion-wise. That is, the coil should be pushed in (or pulled out) until it is just completely hidden by the metal frame (or there-abouts). If the voice coil lies a great deal above or below the metal pole pieces, the output will be reduced, and the speaker will bottom out early in one direction, causing distortion at volume levels lower than normally possible. Before wetting anything, have your voice coil shims set. Do not shim after wetting.

T.

Also, in the highly unlikely event that your cone is not salvagable, Peter knows of a good source for inexpensive replacement cones. The cones might require extra clearance (edge padding) due to the rubber cone edge, but they sound great. I'd recommend a source for more original all paper cones, but I don't know of any that don't require a 100 to 1000 quantity minimum order. Peter's cones do work great.

...But again, you should try salvaging your cone first.

T.

:Also, in the highly unlikely event that your cone is not salvagable, Peter knows of a good source for inexpensive replacement cones. The cones might require extra clearance (edge padding) due to the rubber cone edge, but they sound great. I'd recommend a source for more original all paper cones, but I don't know of any that don't require a 100 to 1000 quantity minimum order. Peter's cones do work great.:...But again, you should try salvaging your cone first.
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:T.
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Great advise Thomas will see what I can do, and try to stay away from the acetone. Somebody has worked on the speaker in the past. The felt is glued down along with the outside edge of the cone with some black, I guess speaker glue. It isn't flexible though. With the toilet paper up under the frame it sounds pretty darn good. I wouldn't have thought about using it but I picked up a radio on Ebay and someone used it on that speaker. Talk about a rattle trap when I removed it. I really like your idea with the film I used 3 thin pieces of cardboard for shims one time and it took an act of congress to remove them after the speaker dried. LOL Thanks A Million, or has that gone up to a trillion now. George T.

The film shims are Peter's idea. They can stick when wet, too, but are far superior to cardboard. Whatever the case may be, try not to get the voice coil wet. That's not good at all.

T.