Hi Bob
Congrats on conquering the problem with your 41-250.
Since your 46-350 problem is a new topic, I took the liberty of making it a new thread.
Since it appears from your photo that the innards of the old electrolytic are still intact, it seems to me that this is, more likely, a case of pot metal having disintegrated. I've worked on a couple of those sets...the ones I've seen had electrolytics in a pot metal can...and the pot metal used for these cans all go bad and disintegrate to a greater or less degree. Sort of like the rubber-covered wiring in 1939-42 Philcos - you can count on these to fall apart.
This is going to be the end result, unfortunately, of ALL cast pot metal items - sooner or later.
Your only recourse is to improvise a steel or aluminum electrolytic can if you want to keep original appearance.
Whew!... I hate to see electrolytic meltdowns!! Did it go "poof" , or was it a fairly "loud" event? I hate those myself!! Personally, I just hope no one was injured!!
Sure looks like pot metal "rot" to me as well. There would be paper fluff all over if it had exploded. Does not even look that swollen either. Some expected age induced swelling (due to increasing leakage and subsequent heating/expansion) may have contributed to the pot metal's demise through cracking and then enevitable pot metal disintegration.
Pot metal breakdown--that explains why there's no collateral damage as well. I just bought the radio and the seller indicated he bought it that way but never got around to restoring it. The radio looks pretty much untouched except that there's a brown wire from the volume pot that's been cut and taped. The other thing I found out (ouch!) is that the chassis is hot, so there's something terribly wrong somewhere.
Nothing terribly wrong; the Model 46-350 is a hot-chassis type set. Be sure to use your iso transformer!
Chuck
I'm glad you said something. I'll put this one away until I get my hands on an iso-transformer. I'm new at this and appreciate every bit of knowledge I can get, especially the safety issues.
Apropos of hot chassis sets, be sure that the line
filter cap(s) are replaced with Y rated cap(s). Also,
I routinely move the switch to the plate side, and use
polarized plugs so that neutral is permanently connected
to the chassis on those sets. As they come, they
are either hot when on, or hot when off, there is
no safe way to plug them in. Moving the switch
alleviates that. I do that on all AC/DC sets, including
the floating ground ones. This runs a slight risk of introducing
hum. I have only had this happen once, and I fixed it
by rerouting the AC line, and making it a twisted pair.
yram, You are correct indeed on restoration of the old ac/dc live chassis!! Depends on how the AC plug is connected onto the AC line cord, and better yet, which side is used when plugging into the AC outlet!! Back then in the old days, AC plugs didnt have a "big spade" on either side of the AC line cord!! Very good observation indeed!! Back when I started servicing these type unforgiving type potential killers, and before I ever owned a AC "isolation trans", I was taught to use the
"one hand only" at a time, while working on these type sets! My best suggestions for "newbies", is keep the ac/dc sets completely "unplugged from AC" while installing new chassis components! Also install a AC line fuse of approx 1/2 amperes, on one side of the ac line cord feeding the chassis first "before" going any further to begin restoration of chassis restoration! I sure dont like the thought of some "newbie" buying a old vintage ac/dc set at a garage sale and "playing around" under the chassis to see if it works or not!! Scary indeed!! "Y" caps are much better than most on the AC line, but I have found replacing the old orig .05 ufs/ with regular .01 ufs on AC line cord could also add safety? Bottom line here, its scary to think about a "newbie" buyer of a old ac/dc type radio from a garage-sale,etc,...
taking it home, plugging it in, and messin-round under the chassis indeed!! Just my thoughts, Randal
I spoke with Wayne Thompson yesetrday (the guy who makes the repalcement 46-350 and 48-350 handles) and he told me that some of them have the pot metqal can, and some an aluminum can. Mine is missing the can, and has old cardboard replacements, so I will either re-stuff an old can, or buy a new can.
I finally got an iso-transformer and I'll be starting on the chassis, soon. I need a can to stuff, also. Mine was definitely rotting pot metal.
YRAM--I'm not sure what you mean about moving the switch to the plate side. I like the idea of making the radio as safe as possible and will definitely use the polarized plug.
Aluminum was a strategic metal during the war, and probably still in short supply for a time afterward. I haven't seen pot-metal cans but I have seen drawn zinc used, which has corroded badly.
By the way, Antique Electronic Supply sells a new 30/30/30/10 aluminum can. It is expensive, butt he voltage ratings on all sections are 475, so it is certainly more than adequate.
justlrnin, hi. moving the switch to the plate side = move switch from ground leg to high side of line and run neutral line cord wire directly to chassis. This has to be done with a replacement "polarized" plug (wide spade/blade neutral). If you don't replace line plug chassis will still be hot sometimes and that sometimes will be when you forget the one hand method and get a belt. PL
And don't forget to confirm that the actual AC outlet is wired correctly!
-Bill