[Radioroslyn]

I picked up this Saal circ'24 or '25 horn speaker to find the driver is open. The base and driver are made of pot metal and they screw together. Well they did in '24 but now it doesn't want to budge. I suspect that the pot metal has warped causing it to be very tight. Have tried some WD-40 and heat from a heat gun. Any ideas?? I'm afraid if I use a large wrench on it it may snap off.
Tnx
Terry

[morzh]

Terry,

Tapping with a mallet and a nail set to dislodge watever bond has formed over the years. Axially as well as to the wrench.
WD40 is not a loosener by purpose, penetrating oils are. Usually kerosene-based.

[sam]

pb blaster works great on loosening things

[Radioroslyn]

Well guys I took a mallet and with a few tight taps I manged to break off the driver. The driver is a goner as it is stuck fast and would probably break it trying to get it apart. So onward to the JB weld to put the broken pieces back together. It will get a small PM speaker and opt to match the impedance.
Terry

[morzh]

Well, why not. A PM with OPT will work just fine.

[Radioroslyn]

Well it does ruin the value of it for the purist, which I'm not one of.
Terry

[morzh]

Heck, if I were a purist, I'd have to stop restuffing caps.
Any purist is one only up to a point. Any restoration is a compromise.
If you think of it, most famous artworks are now full of today's repro paints from all restorations. Da Vinci, Rafael, all those Sixtine Chapel pics....so, what, do we stop considering Mona Lisa as a Da Vinci's work then? or does it ruin its value?

Fundamentlism is always....bad. At best it is impractical.

[Arran]

An easy way to replace those is to harvest the driver out of an old headset, the impedance is usually close enough. You have to be careful with some 1920s horns, sometimes they are worth more as original, but non functional, then working but having a transistor radio speaker in the base. With few exceptions they were not paired with any radio in particular, other then the big makes like Atwater Kent. They are not the sort of speaker that one would use for much other then demonstration purposes. There are also a lot of horns around that no longer have the base, or are matched to the wrong base, I think I would be more inclined to convert one of those then to take taking an original but stubborn pot metal one apart.
Regards
Arran