The test you suggest is a good one. I'll do it for sure. However, I am pretty sure that the spring could give sufficient energy for correct speed at one point (coils slide by one another) and then, as it uncoils, encounter an area of sticky old grease, impeding proper release of energy, especially since we are dealing with century old springs and equally old lubricant.
Ron L -----Original Message----- From: phono-l-bounces at oldcrank.org [mailto:[email protected]] On Behalf Of Robert Wright Sent: Monday, September 01, 2008 11:43 PM To: Antique Phonograph List Subject: Re: [Phono-L] Amberola 30 erratic speed Last thought -- listen to a cylinder you know well and wait for the speed to drop. Back the reproducer up about 20 or 30 grooves and see if it does it in the same spot, within about 3 or 4 grooves. If so, it's not the mainspring, or anything other than something the carriage encounters near that physical location along the feedscrew, whether the contact point of half-nut to feedscrew, or the shaft the carriage rides along the length of the playback. Forgive me for speaking out of school, but if it were the mainspring, it just sems like there'd be no point at which you had reliable speed. These guys are the experts, but at least give the 30 this 'repeatable error' test first. ----- Original Message ----- From: "Ken Danckaert" <[email protected]> To: "Antique Phonograph List" <phono-l at oldcrank.org> Sent: Monday, September 01, 2008 3:37 PM Subject: Re: [Phono-L] Amberola 30 erratic speed > Your problem is in the mainspring. It needs to be pulled and ALL the old > lubrication removed. 4"0" steel wool and wd40 will do that. Relube and > put > the spring back in. That will get rid of the problem. DON'T soak it in > kerosene or some other short cut to cleaning. The old stuff has got to > come > off the spring. > > Ken Danckaert > > On Mon, Sep 1, 2008 at 12:50 PM, Ron L'Herault <lherault at bu.edu> wrote: > >> OK, gang, it is time to tap into the lists' wisdom. I'm working on an >> Amberola 30. The hook came unsoldered and the reproducer needed a >> rebuild. >> Those two easy repairs (the spring was in the case)completed, I tested >> the >> phonograph and found that the speed is a bit erratic. It will sound nice, >> then slow just a bit then return to speed for a while only to slow again. >> The carriage moves easily and the horn bobbles and rotates as it should. >> The governor is lubricated and the pad has been oiled. There is no >> evidence >> of crud or damage to the governor disk. There were a few teeth on the >> large >> hear that had a bit of damage but a bit of judicious filing has cured the >> noise the damage created, and besides, the speed variation is more random >> than the cycle of the gear noise. I'm thinking that the mainspring may >> need >> to be removed, cleaned and re-lubricated but I thought I might see if >> there >> is anything else I missed before tearing it apart. >> >> Thanks, >> >> Ron L >> >> >> _______________________________________________ >> Phono-L mailing list >> http://phono-l.oldcrank.org >> > _______________________________________________ > Phono-L mailing list > http://phono-l.oldcrank.org > _______________________________________________ Phono-L mailing list http://phono-l.oldcrank.org
