Talk about replacing ALL old electrolytics and paper caps as a general principle... right?
That's my motto! Yes that's good advice!

But I was REALLY pleasantly surprised tonight as I tore into this nice old Stromberg Carlson 400H.
http://www.nostalgiaair.org/PagesByModel/498/M0021498.pdf

It was made waaay back in 1939...
....that's 70 years ago... right?

Well surprisingly the set was playing perfectly well when it arrived.
... and as I turned over the chassis to see what caps had already been replaced contributing to this good performance... I saw to my surprise that NOTHING was ever touched. Everything was EXACTLY as it left the factory... even the 3 section electrolytic can.

I did replace EVERY cap though anyway...including all the "micas" and .... as I did it I measured each one when removed, to see how far they had deteriorated in 70 years. Well... guess what?
Every single cap tested perfectly (except one 100pf cap that was at 25pf) otherwise all were great including the electrolytics!!

I would never have left them in there but it sure says something about the parts quality that Stromberg Carlson used back then.

I love the performance "quality" that this set demonstrates. The tuning is ultra quiet between stations and the speaker cone is tough as nails (thick paper) and the dial calibrates so perfectly and easily.

This set just seems to oooze good engineering and quality.

Kudos to whomever it was that engineered it and also to who procured and manufactured the parts and put this one into the production cycle.

Hi Peter,
I have an old CQ magazine hich describes all of the capacitor types available in 1950. Paper wax capacitors were metntioned. It claimed that paper wax capacitors are reliable as long as they are sealed against moisture infiltration. However, most of them are not.
Since what we are doing is a kind of artistic or historic preservation, I wonder if changing the capacitors when they are of high quality is good thing to do.
This rarely is encountered of course. We all assume that the capacitors in a 70 year old radio are rubbish, and we are almost always right. I pose the question for those rare times when it isn't so.

Best Regards,

Bill Grimm

I work at what remains of the old Stromberg-Carlson factory here in Rochester,NY. They did build fine radio,television and telephone equipment before joining in with General Dynamics and becoming a defense electronics industry.Today we build the Harris/RF Communications Falcon III radios(see our website) on Carlson Rd.to support our warfighters. Unfortunately no more civilian electronics. I have a 515M that features the Acoustic Labyrinth(a tuned speaker enclosure port that exits underneath toward the floor for robust bass) and a US Army Signal Corps BC-348P communications receiver,both of which I thoroughly enjoy looking at and listening to. -Walt.

I have the console which is 1/2 of a circle. It is a really nice radio and I have not done anything to it yet. Also have AK 711J in wonderful monster cabinet.