Collins 356B - mistake in schematic?

[athnony]

So I'm wondering if I found a mistake in the schematic, or if I'm just too much of a novice to understand why C301B is shown with the positive connected to the B- rail

I recapped two 356Bs according to the schem and had this cap blow on me in both units. I could've sworn the original can-style multicap had that terminal connected to R304+305, so wouldn't that mean the positive should be facing opposite (negative connected to B-) of what's shown in the schematic?? Or maybe there's some old school voodoo I don't know about?

 

[rock soderstrom]

C301b is drawn with the wrong polarity. It forms with R313 the last PSU ripple filter for V301 and must be installed definitely this way, otherwise boom!



What this funny D lying on the back means I do not know. Maybe member EMRR Doug can tell us....

 

[beatnik]

C301D is also the wrong way around

The symbols correspond to the various sections on the multi can capacitor

 

[rock soderstrom]

The symbols correspond to the various sections on the multi can capacitor

That's what I thought, but I wasn't sure...

 

[ruffrecords]

Looks like they use the same symbol for all types of capacitor, even the 0.0047uF interstage coupling caps which are obviously unpolarised. I agree it is a drawing error. They really should have used an unambiguous symbol for a polarised capacitor.

Cheers

Ian

 

[gyraf]

..isn't it the small triangle mark that designates both the type and the plus-side?

 

[athnony]

Thank you! I thought I was losing it for a minute.

..isn't it the small triangle mark that designates both the type and the plus-side?

I think it's just the symbol on the multi-can - you can kind of make out the triangle in the bottom of this photo I took before recapping.

From the looks of it, beatnik is right about 301D as well

 

[athnony]

Happy to report this little space heater seems to be working great + sounds incredible!

I noticed another error... C302 should be 4uF, not 40.

Here's a corrected schematic + original manual for reference in case anyone needs it in the future!