Magnetic Return Structure, Help Me Understand

[Phil-G]

GM I loved slot cars in the mid '60s! There were two local places I frequented in Pico Rivera and Whittier, CA with my mediocre cars and Cox controller. I had an inline 1/32 scale and a sidewinder GT-40 looking 1/24 scale. My mom said that it was all a fad and would be gone within a year. I argued that oh no, slot cars were here to stay, but both racing tracks were closed within a year or so. Mom was cool enough not to say "I told you so."

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[Old Guy]

Used to do hand rewinds on slot car motors, had a setup with two single edge razor blades to balance on. Actually built some nice running motors..big Mabuchis for endurance racing.
Got older and had to make a living, so drifted away as the tracks were closing. It just got to be too much effort and expense. I think that is what killed the sport.

[Earl K]

Bowtie,

I'll wrap up my thoughts now ( about your initial "welding" query on Magnetic Return Structures ).

Here's the W.E. 1947 catalogue introducing their new line of post war equipment.

WELoudspeakers47

After some careful reading of WE's ( internal company review of the products ) I ended up concluding that W.E. didn't think welding on their M.R. structures was a cause for concern. The magazine does in fact mention that welding MRS parts together being superior to soldering them together.

That's really incidental info I realize but it came at a time when WE was launching their new line ( & seemed to be pulling out all stops on the engineering fronts ).

Their ( cost no-object ) 728b speaker really did break new ground ( having );

(i) Cast Magnetic Return Structures
(ii) 4" Voice-Coil ( for better power dissipation )
(iii) Rear-Vented Voice-Coil
(iv) Finally, at least the early models were built with the magnetizing coil embedded within the return structure ( access to the leads must have been welded over after the charge was applied to the alnico ).
- I really find that tidbit to be interesting cause I have to ask myself why the need to apply an internal charge ?


The 754(a+b) 12" speakers were a bit more utilitarian and used welded Steel Casings just like Altec.
- So obviously WE didn't think this was such a heavily compromised approach that it needed to be avoided in their new line-up .

Anyways, all totally circumstantial info, as "food-for-thought" .

[Elitopus1]

Very interesting thread guys. I have wondered too why Altec made the switch. I figured it was just for cost savings.

Obviously there are more differences than just the magnetic structure, but I prefer my older 802D drivers to the newer 802G. The ?better? technology doesn't sound better to me.

[Earl K]

Very interesting thread guys. I have wondered too why Altec made the switch. I figured it was just for cost savings.

Obviously there are more differences than just the magnetic structure, but I prefer my older 802D drivers to the newer 802G. The “better” technology doesn't sound better to me.

Apparently, casting costs more ( not less ).

My 802D drivers have a cast return POT ( btw ) and they are tapered the same as the 802G.